Designing Buildings - User contributions [en]

Sustainability in building design and construction

2014-07-09T10:35:45Z

Susan Poupard:

Sustainability is a broad term describing a desire to carry out activities without depleting resources or having harmful impacts, defined by the Brundtland Commission as '''meeting the needs of the present without compromising the ability of future generations to meet their own needs''.' ([http://www.un-documents.net/wced-ocf.htm Brundtland Commission, Our Common Future, 1987]). Some broader descriptions include social and economic welfare although these can confuse the basic issue of the depletion of resources.

Sustainability in building developments is a vast and complex subject that must be considered from the very earliest stages as the potential environmental impacts are very significant (ref [https://www.innovateuk.org/built-environment Technology Strategy Board]). The built environment accounts for:
*45% of total UK carbon emissions (27% from domestic buildings and 18% from non-domestic)
*73% of domestic emissions arise from space heating and the provision of hot water.
*32% of landfill waste comes from the construction and demolition of buildings.
*13% of products delivered to construction sites are sent directly to landfill without being used.

Once it has been decided to build a new building, as opposed to say changing working practices or refurbishing an existing building, a very significant commitment to consume resources has already been made. Designers and contractors may be able to help limit that consumption, but they cannot change the overall commitment.

This consumption of resources can be even more significant if the client makes a decision to relocate, with the impact this has on their staff, requiring that they either move house or change their travel plans. Decisions such as this which are often made outside of any environmental assessment process can have a far greater impact on sustainability than decisions that designers are able to influence such as the form of the building and selection of materials. Key decisions may be picked up by an environmental impact assessment on larger projects, but even then, this can be a post-rationalisation process used to justify decisions to the local planning authority, rather than a genuine decision making process.

Clients may wish therefore to appoint an independent client adviser with specialist knowledge of sustainability during the very early stages of their project (before the consultant team has been appointed) to help them address these high level decisions.

Clients may have an existing environmental policy, that sets out an overall sustainability vision, as well as detailed objectives and targets. They may also have environmental accreditation such as ISO 14000 (a series of standards which provides a framework for environmental management). Other standards may be imposed by funders, the building regulations, and planning legislation (including the possible need for an environmental impact assessment). It is wise however to write a specific environmental plan for the development being considered, as building projects involve many detailed issues that go beyond the scope of an existing corporate plan.

A project-specific environmental plan could form part of the brief, or on larger projects might be a stand-alone document. It might include an overall vision, objectives and and specific targets in relation to:
*Business planning: the need for a new building as opposed to doing nothing, refurbishment or changes in working practices.
*Selection of consultants: contractual requirements in relation to the selection of materials, monitoring and reporting, track record, environmental accreditation and qualifications of staff.
*Selection of location: availability of transport, the selection of a greenfield or brownfield site, the local availability of resources and services, the local infrastructure and local ecology.
*Project brief: procurement route, travel plan, working methods, standards, ecology and landscape, energy use and energy source, flexibility and durability, waste management, water management, material selection and pollution.
*Design: energy use and energy source, embodied energy, use of harmful materials, material sources, ecology and landscape, flexibility and durability, waste management, water management, disposal, travel plan and pollution.
*Tender: contractual requirements such as monitoring and reporting, working practices, track record, environmental accreditation and qualifications of staff.
*Construction: transport, embodied energy, use of harmful materials, material sources, working methods, site waste management plan, recycling, pollution, wheel washing, dust generation and noise nuisance.
*Operation: energy source, energy use, water management, maintenance, resource management, waste management, flexibility, durability, landscape and ecology, pollution, evaluation and feedback.
*Resilience to climate change.
*Disposal: dismantling and demolition, re-use, re-sale and recycling, landscape and ecology, hazardous materials and pollution.

The environmental plan should:
*Set specific, measurable targets.
*Set standards that must be adhered to.
*Establish risks and mitigation measures.
*Establish procedures for communication and training.
*Establish procedures for monitoring and reporting.
*Establish procedures for revision and updating.

Environmental plans require policing, and on a large project this can be a full-time job for a specialist. At the client level, a senior champion should be appointed to take responsibility for environmental matters.

Predicting the likely environmental performance of a development during the design phase is becoming more important as regulations become increasing strict. As well as the building regulations, and government targets for low carbon construction (see [http://www.bis.gov.uk/constructionigt low carbon construction plan]) the National Planning Policy Framework makes clear that there should be a presumption in favour of granting planning permission for sustainable development, this might include low-carbon developments, and developments with resilience to climate change. This should be reflected in design and access statements for outline planning applications.

There are a number of assessment tools and standards available to help assess environmental performance:
*[http://www.breeam.org/ BREEAM.]
*[http://www.passivhaus.org.uk Passivhaus].
*[http://projects.bre.co.uk/sap2005/ SAP] the Government's Standard Assessment Procedure for energy rating of dwellings.
*[http://www.usgbc.org/DisplayPage.aspx?CategoryID=19 Leadership in Energy and Environmental Design] (LEED), an international green building certification system.
*[http://www.communities.gov.uk/planningandbuilding/sustainability/codesustainablehomes/ The code for sustainable homes].

These assessment techniques are beginning to allow whole-life costing to form a fundamental part of the design process as it becomes possible to demonstrate that higher initial costs can sometimes result in lower long-term impacts and greater long-term benefits. Demonstration of actual performance in use may be necessary through requirements for a Energy Performance Certificates (EPC's) or Display Energy Certificates (DEC's)

Appointments should make clear the extent and standard of environmental performance and assessment that is required.

= Find out more =

=== Related pages on Designing Buildings Wiki ===
*CRC Energy Efficiency Scheme.
*Earth overshoot day.
*Ecological impact assessment.
*Emission rates.
*Energy Act.
*Energy certificates.
*Energy Performance Certificates.
*Energy Related Products Regulations.
*Energy targets.
*Environmental consultant.
*Environmental impact assessment.
*Environmental legislation.
*Intergovernmental Panel on Climate Change.
*Mean lean green.
*National Planning Policy Framework.
*Passivhaus.
*Site waste management plan.
*Smart cities.
*Sustainable materials.
*Sustainable timber.
*Sustainable urban drainage systems.
*U-value.
*Zero carbon homes.
*Zero carbon non-domestic buildings.

=== External references ===
*The RIBA has produced a [http://www.ribabookshops.com/uploads/9a0204f4-8775-d644-c9d1-b2d508c5924b.pdf Green overlay] to the Plan of work. This provides supplementary guidance on the integration of sustainability into the design process.
*[http://webarchive.nationalarchives.gov.uk/20100503135839/http://www.ogc.gov.uk/documents/CP0016AEGuide11.pdf Sustainability, Achieving Excellence in Construction Procurement Guide, OGC, 2007.]
*[http://www.greenspec.co.uk/ Greenspec green building products and other guidance.]
*[http://www.greenspec.co.uk/glossary-of-green-building.php Greenspec glossary of green terms].
*[http://www.carbonlite.org.uk/ Carbonlite an AECB initiative providing the tools and knowledge to create low-energy buildings.]
*[http://www.sustainablebuild.co.uk/ Sustainable Build: The Complete Guide to Building Sustainably].
*[http://www.aecb.net/ AECB], a network of individuals and companies with a common aim of promoting sustainable building.
*[http://www.cibsedesigncompass.org.uk/ CIBSE design compass.]
*[http://www.architectsjournal.co.uk/sustainability/ Architects Journal, article on sustainability].
*[http://www.greenbuildingstore.co.uk/ Green Building Store, products for low energy buildings].
*[http://www.zerocarbonhub.org/definition.aspx?page=9 Zero Carbon Hub: Allowable Solutions for Tomorrow’s New Homes].
*[http://www.communities.gov.uk/publications/planningandbuilding/draftframework Draft National Planning Policy Framework - presumption in favour of sustainable development].
*[http://webarchive.nationalarchives.gov.uk/+/www.dh.gov.uk/en/Aboutus/HowDHworks/Servicestandardsandcommitments/Sustainabledevelopment/DH_4105876 The Framework for Sustainable Development on the Government Estate] has sections covering procurement and estate management.
*[http://www.cibse.org/index.cfm?go=page.view&item=847 CIBSE Example structure for an energy policy].
*[http://www.bsria.co.uk/services/design/soft-landings/ BSRIA Soft Landings].
*[http://www.architecture.com/FindOutAbout/Sustainabilityandclimatechange/ClimateChange/Toolkits.aspx RIBA Climate Change Toolkits].
*[http://www.wrap.org.uk/construction/ WRAP (Waste & Resources Action Programme) resource efficiency tools].
*[http://www.environment-agency.gov.uk/business/sectors/36998.aspx Environment Agency guidance on sustainable drainage systems and sustainable urban drainage systems (SUDS)].
*[http://www.hm-treasury.gov.uk/green_book_guidance_environment.htm Cabinet Office summary of government advice on sustainability].
*[http://www.architecture.com/Files/RIBAProfessionalServices/RIBAGuidetoSustainabilityinPractice.pdf RIBA Guide to sustainability in practice].
*UK Green Building Council: Pinpoint: [http://pinpoint.ukgbc.org/ Data base of sustainability resources, training and tools].
*Carbon Trust [http://www.carbontrust.com/resources/guides/energy-efficiency/low-carbon-buildings-design-and-construction Low Carbon Buildings] and [http://www.carbontrust.com/resources/guides/energy-efficiency/buildings-energy-efficiency Buildings energy efficiency] guides.

[[Category:Other_legislation]]
[[Category:Planning_permission]]
[[Category:Sustainability]]
[[Category:Construction_techniques]]
[[Category:Cost_/_business_planning]]
[[Category:Design]]

Solar thermal systems

2014-07-09T10:34:05Z

Susan Poupard:

= Introduction =

The term 'solar thermal' is used to describe a system where the energy from the sun is harvested to be used for its heat. Solar thermal systems differ from solar photovoltaics which convert sunlight directly into electricity. The use of the term 'solar thermal' is also associated with the integration of 'passive' heating and cooling technologies in buildings.

The UK offers a good climate for solar thermal systems benefiting from around 60% of the solar energy that is received at the equator and similar amounts to other northern European states. The amount of solar radiation received (also known as 'solar insolation') is measured in kWh (kilowatt hours) over a particular time period. On a typical July day in Coventry there would be around 5kWh of solar insolation.

Solar thermal systems are rated in kWth (thermal kW). The total of all solar thermal installations in the UK in mid 2010 was around 400,000 kWth.

The main application for solar thermal systems in the UK is domestic hot water heating although there are also 'combisystems' that use non-potable thermal stores directly linked with low temperature space heating (such as underfloor heating) and, in warmer climes, there are more technically challenging solar powered refrigeration systems.

A 2011 Energy Savings Trust report ([http://www.energysavingtrust.org.uk/content/download/29047/348320/version/2/file/Here+comes+the+sun+-+solar+hot+water+report.pdf Here comes the sun: a field trial of solar water heating systems]) indicated that properly installed and operated systems can provide 60% of domestic hot water energy. Typical carbon savings from a well-installed and properly used system in a house amount to around 230kgCO2/year when replacing gas and 510kgCO2/year when replacing electric immersion heating.

= The potential for solar heating in the UK =

Solar thermal has had a great boost in recent times with the publicity around the Renewable Heat Incentive and the Green Deal, and as a result the adoption of solar collector technologies is gaining pace in the UK. Other European countries such as Germany, have seen a steady growth in the installed area of collectors since the early 1990’s (so far around 10million kWth).

In the UK the average annual available solar irradiation varies between around 1,200 kWh/sq m on the south coast of England and up to 900 kWh/sq m in Scotland. Southern England has similar insolation to that in Holland, northern France and northern Germany. Solar data for the whole of the UK is available on the [http://www.rensmart.com/Weather/PVGISSolar PVGIS Solar Map]. 

With only 55% of the sun’s light being visible, and much of the sunlight being diffuse there is potential for solar-powered water heating even on 'cloudy' days. A properly designed and installed solar thermal system can maximise the capture of this power and translate 60% of it into useful energy for hot water.

Solar systems have a number of positive attributes that are likely to promote greater use in the UK:
*They provide no exhaust gases (there may be some related emissions from pumping energy if this is necessary).
*Good quality collectors will have a life of 20 to 30 years.
*They offer long-term independence from fuel price inflation.
*Total cost analysis is largely based on the known, initial capital cost.
*Low maintenance.
*Potential for government subsidies.
*Certainty of fuel supply.
*They can improve the environmental credibility of building.

= Government funding =

All solar thermal installations of 45kWth capacity or less need to be certified under the [http://www.microgenerationcertification.org/ Microgeneration Certification Scheme] (MCS or equivalent) to be eligible for financial assistance from the government. This provides a safeguard against poor quality and inefficient installations. Both the technology and the company or person installing the system needs to be certified under the MCS scheme. When applying for financial support, details of MCS certification will be required. For solar thermal installations larger than 45kWth, [http://www.ofgem.gov.uk/e-serve/RHI/Pages/RHI.aspx Ofgem] will verify eligibility.

The [http://www.estif.org/solarkeymark/ Solar Keymark] is a quality label for solar thermal collectors and systems that fulfil minimum requirements according to specific European standards. It is recognised in the UK as equivalent to MCS for equipment, the installer still needs to be MCS certified.

Solar thermal panels for commercial hot water installations up to 200 kWth are eligible for the [https://www.gov.uk/government/policies/increasing-the-use-of-low-carbon-technologies/supporting-pages/renewable-heat-incentive-rhi Renewable Heat Incentive] (RHI). Domestic installations are expected to be included in the RHI scheme in 2014.

The [http://www.decc.gov.uk/en/content/cms/meeting_energy/renewable_ener/incentive/factsheet/factsheet.aspx Renewable Heat Premium Payment scheme] is available for households that instal renewable heating, including solar thermal systems. These are direct payments to the home owner of £300 to subsidise the cost of installation and in return for the payments, participants are asked to provide some feedback on how the equipment works in practice and suppliers are asked to provide a follow up service on any issues that are raised. The aim is to boost confidence in the technology and the information received aims to help Government, manufacturers, installers and consumers to better understand how to maximise performance of the various technologies.

The [http://etl.decc.gov.uk/etl Enhanced Capital Allowance (ECA) scheme] enables businesses to claim 100% first-year capital allowance on investments in eligible solar thermal equipment against the taxable profits in the period of investment. However since the 2012 budget this provision is being phased out in recognition of the RHI.

= Efficient solar thermal systems =

The key for efficient system sizing is to meet as much of the annual domestic hot water requirement as is economically possible. This is known as the solar fraction and ranges from zero, for no solar energy use, to 1 to that indicates all the heat for the annual domestic water requirements is supplied by solar energy. The solar fraction of a particular system is dependent on many factors such as the load, the collector and storage sizes, the operation, and the climate.

Experience from Germany where there is a very mature market shows that systems are commonly oversized, having been based on assumed hot water consumption that is much higher than reality. Typically in summer the hot water usage was not reached and the expected solar insolation was exceeded. Combined with poor materials this led to overpriced, oversized systems that failed to meet expectations. Problems also arose in many cases due to poor integration with existing traditional hot water service systems. In the UK it should be reasonable to expect a solar fraction of 60%.

It is also important that when the system is designed it is able to deal with stagnation of water in the collector. This is the point at which the water system cannot accept all the heat from the collectors and so the heat from the sun may raise the temperature of the solar collectors well beyond 100°C, causing evaporation inside the system. Long periods of stagnation may be a sign of an over-estimation of solar fraction, where solar collectors are too large (and uncontrollable) for the their particular application.

== Sizing solar thermal hot water systems ==

The method for sizing a solar thermal system is quite different to gas, oil or electric hot water systems. Conventional systems are sized based on peak hot water demand with additional capacity to provide potential for future expansion and safety margins.

A solar powered system would normally be sized so that it does not provide any more energy than is required to recharge the store of hot water in periods of low demand. This is normally a summer condition. A larger store may allow a greater solar fraction but an oversized store will mean that at times of low solar availability, stored water temperatures may be too low (at additional cost and space). The UK Building Regulations require that the store should be at least 80% of the daily hot water demand or 25 litres for every sq m of collector area.

Practically, where systems are being installed in existing buildings, the capacity can be based on measurements of actual demand taken in periods of low consumption in summer. In new buildings they can be sized based on measured data in similar buildings.

There will almost certainly be a need to provide an auxiliary means of heating the water (normally from the main heating systems) for when demand cannot be met by solar collection. In this case, the solar hot water can be used as a means of preheating water that is subsequently fed into a separate continuous-flow water heater or a traditional hot water calorifier/cylinder. Purpose made cylinders are frequently used where a solar coil takes up the lower space in the cylinder and a traditional primary heating coil is in the top half.

Energy used in pumping can be significant, and so it is important to minimise pressure drops in systems through careful pipework design and by exploring the use of solar powered pumping.

The means to prevent legionella must be carefully thought through as poor scheduling of 'pasteurisation' cycles can reduce the opportunity to capture heat from the sun. The high temperature water can be circulated around the tank, but this will break up the temperature stratification (that would normally leave cooler water at the bottom) making the solar coil less effective.

= Collecting solar heat =

The selection of the type of collector will depend, amongst other things, on its temperature in operation and application. Collectors have several elements that combine together to ensure a consistent performance and longevity, including:
*The geometry and type of the absorber.
*The absorber coating.
*The covering material and casing.

Basic operation is reliant on the 'green house effect'. Incident (high energy, short wavelength) solar radiation passes through the transparent or translucent surface of the solar collector and heats a metal or plastic surface. The glazed panels reduce the heat re-radiated back out and will also reduce convection of heat from the hot absorbing surface.

Unglazed (flat plate) solar collectors are used for low temperature water applications (such as swimming pools) where the loss of heat will not be as significant as with higher temperature panels.

= The solar collector =

There are two main types of solar thermal collectors currently used in the UK:
*Flat plate collectors
*Evacuated tube collectors.

There are a number of variants of these in various materials, with the choice driven by the temperature of operation and the location and available area for mounting the panels.

Both types of absorber can reach high temperatures in operation and so must be properly constructed to maintain a long-lasting, consistent heat transfer between the absorbing surfaces and the tubes/channels through which the fluid flows that carries the heat to the hot water store. The collector must comply with [http://shop.bsigroup.com/ProductDetail/?pid=000000000030216715 BS EN 12975 - Thermal solar systems and components]

== Unglazed flat plate collectors ==

Unglazed panels are used where the required water temperature is no greater than 10K above the temperature of the air around it. This is suitable for swimming pool applications but not appropriate for domestic hot water systems.

== Glazed flat plate collectors ==

[[File:Flatplatesolarcollector.jpg|557x360px|alt=Flatplatesolarcollector.jpg]]

Image: Flat plate collector

Glazed flat plate collectors are most suitable where the water temperature is between 10 and 50K above the surrounding air temperature, and so are ideally suited to domestic hot water applications.

The typical construction of a glazed flat plate collector comprises a lightweight metal or polymer tray that contains a layer of insulation (normally glass fibre) to prevent heat loss via conduction through the rear of the collector. The 'absorber' is designed to maximise solar irradiation absorption and is likely to have selective surface coatings to maximise solar gain and minimise re-radiation. For metal absorbers black chrome or nickel coatings are typically used.

A series of waterways bonded to the absorber carry the heat transfer fluid (water or glycol mix) through and away from the collector. The collector has a transparent glass or plastic cover across the whole 'aperture' with a low thermal expansion coefficient and high transmission efficiency to maximise net incoming solar radiation and minimise convection losses. Transmission efficiencies for good quality products are over 90%, absorption efficiencies 95%, emissions (losses) 5% and maximum thermal efficiencies of around 78% over the year.

Copper is commonly used for the tubing in the collector and aluminium or copper for the absorber sheets (with stainless steel being used when aggressive mediums flow through the absorber as in direct-fed swimming pool panels). Polymer and butyl rubber materials are used for applications where the system is designed to carry plain water that may freeze. Whatever tubing is used there must be a good thermal bond between the tubing and the absorber plate. Any connections to the panels together with the immediate fluid loops are likely to be made using mechanical joints rather than soft solder or even brazing as they are subject to high thermal stresses.

To provide good performance, flat plate collectors have inclined mountings or are integrated into an appropriately pitched south facing roof between 30° and 40° to the horizontal.

== Evacuated tube collectors ==

The evacuated tube works in the same way as a thermos flask to reduce the convective and radiative heat loss from the collector back to the environment. They also frequently include some form of focusing reflective surface to provide less dependence on solar position. Since they are more effective per unit area than flat plate collectors they require a smaller installed area and are competitively priced.

The construction of an evacuated tube collector is entirely different to that of a glazed flat plate collector. There are two main types of evacuated tubes. Direct flow evacuated tube collectors, and heat pipe evacuated tubes.

The encompassing tubes themselves can be of a single skin or, more likely, a twin wall Dewar Tube ('thermos flask’) made from borosilicate glass, a glass with high chemical and thermal shock resistance.

In a common application (known as the ‘Sydney’ tube, after its developer, Sydney University), the outer tube is transparent allowing solar radiation to readily pass through (90%+ transmissivity) and the inner tube is coated with a selective coating (eg aluminium based) that provides high solar absorption and minimal reflection.

[[File:Sydneytube.jpg|302x224px|alt=Sydneytube.jpg]]

Image: Sydney tube.

If a tube develops a leak a silver-coloured barium deposit inside the tube turns a white colour when it reacts with atmospheric oxygen.

In direct-flow evacuated tube collectors, the heat transfer fluid is pumped through a copper ‘U’ pipe in each tube and the U tube is bonded to a circular absorber that is slid inside of the Sydney Tube. Heat pipe evacuated tubes consist of a heat pipe inside an evacuated tube. The pipe, which is a sealed copper pipe, is then attached to a heat transfer fin that fills the tube (this is the absorber plate). Protruding from the top of each tube is a metal tip attached to the sealed pipe. The tubes are mounted, the metal tips at the top, into a heat exchanger or manifold assembly. Water, or glycol mix, flows through the manifold and picks up the heat from the tubes. The copper at the tip of the heat tube can reach well over 150 degrees, able to heat water to 90 °C on hot days and to 60°C in the winter.

A self-limiting capability makes the heat pipe collector very tolerant to extreme temperatures. A large number of variations of the absorber shape are available including those with integral reflectors.

As with flat plate collectors evacuated tubes collect global insolation, however, their efficiency is higher than flat plates at low incidence angles so they can be more effective over a longer period in the day and when the sun is low in the sky. They can be fixed practically flat on the roof or vertically on a façade. Even if the location is not quite directly facing due south, the tubes can be adjusted to maximise solar irradiance.

The completed evacuated tube collectors typically comprise a manifold and a series of glass tubes (typically 20 of 30) connected in parallel.

[[File:EvacuatedTubes-photo.jpg|436x144px|alt=EvacuatedTubes-photo.jpg]]

Image: Evacuated tubes fitted to a roof.

Whilst transmission efficiencies, absorption efficiencies and emissions are comparable to those offered by glazed, flat-plate collectors, the thermal efficiency is higher as a result of the presence of the vacuum with typical values of 83%. The actual increase in efficiency at ‘normal’ operating temperatures, as would be used with a hot water system, are likely to be somewhat less.

The increased efficiency (particularly at higher temperature) will lead to higher stagnation temperatures. This means that the materials associated with an evacuated tube installation must be rated at an appropriately high temperature.

Evacuated tubes are not as sensitive to positioning as flat plates but are more challenging to integrate seamlessly into the fabric of a building.

= Solar thermal installations =

As with any heating and ventilation installation, specialist knowledge and expertise is required to design, instal and maintain solar thermal systems. (See B&ES's '[http://www.b-espublications.co.uk/Ecommerce/ID/69/Product/SolarHeatingDesignandInstallationGuide/Details.aspx Solar Heating Design and Installation Guide]').

For commercial installations on flat roofs it is likely to be cost effective to provide an appropriately designed framework so that there is correct collector tilt and azimuth (orientation). As collectors may be used as part of the fabric it is advantageous to integrate their needs (tilt, orientation, fixing and access) early on in the design process. Flat plate collectors are likely require a higher tilt angle than evacuated tubes.

== The solar thermal system ==

The typical components of an indirect solar thermal system are shown in the diagram below. This diagram and others in this article are simplified and do not show the full controls for efficiency and safety needs however it is essential to note that no means of isolation should be placed between the collector and the safety relief valve.

[[File:Solar basic functional control.gif|1163x923px|alt=Solar basic functional control.gif]]

Image: A closed pumped system.

The water supplying the domestic hot water outlets is potable but the primary water from the solar collectors may be a glycol mix or non-potable water in indirect systems. NB for direct systems (that heat the domestic hot water directly in the collectors) it must be potable.

In many stores, to maximise the heat capacity, and to make water available for space heating, the water drawn off from the solar cylinder can be at a temperature that is too high to pass directly to hot water outlets. Some mixing arrangement, or a secondary, lower temperature will be used to ensure safe temperatures.

The design of the systems and their installation should specifically prevent the following:
*Scalding risk from steam or hot water. Failsafe control is required to keep temperatures safe at water outlets.
*Freezing of fluids where it might cause damage or block pipes and safety valves.
*Accumulation of solids or bacteria. Some water treatment may be needed, particularly in direct systems.
*Legionella bacteria developing within the consumed drinking or shower water. The system operation must meet the requirements of HSE [http://www.hse.gov.uk/pubns/books/l8.htm Code of Practice L8] for the control of Legionella. This will normally mean a loss in overall seasonal efficiency as auxiliary heating will be required and must be maintained in use.
*Degrading of water quality due to contact with materials and fittings during stagnation. The oversizing of systems will make the chances of stagnation more likely.
*Backflow or thermo-siphoning of heated water into a cold water cistern.
*Disturbance of stratification in the solar storage vessel during normal operation. This will be disturbed in 'sterilisation' cycles.
*Loss of dedicated solar storage capacity. Systems that are designed to operate with storage will stagnate if they are run without the storage being available.
*Loss of liquid from the system through overflow. Any liquid that is lost has to be replaced. This will affect the composition of the anti-freeze additives and will also allow more oxygen and solids into the system. The expansion vessel should be large enough so that any stagnation does not cause fluid loss through the safety device. In closed systems a heat dump mechanism, typically a radiator, can be used to dissipate heat when the hot water store can accept no more.

Systems in the UK are likely to be either a fully-pumped or drain-back configuration. In climates where freezing is unlikely syphonic systems may be used but there application is unlikely in the UK.

== Fully pumped systems ==

This is the dominant type of system that is used in residential property through to large commercial and industrial applications. They are generally designed so that the exposed components will not tolerate freezing liquids and so must circulate water including glycol antifreeze in a closed loop separated from the potable domestic hot water using a coil to exchange heat in the cylinder.

[[File:Solar thermal simple sealed system.gif|998x898px|alt=Solar thermal simple sealed system.gif]]

Image: A simple sealed solar thermal system.

Some systems are available using materials and pipework that can accept freezing water. These can use potable water in a direct system avoiding the need for a domestic hot water heat exchanger. Since the water is being continuously refreshed there may be some water treatment needed to prevent an accumulation of scale or solids.

[[File:Direct solar.gif|1065x771px|alt=Direct solar.gif]]

Image: A direct solar system using potable water.

Temperature sensors compare the temperature in the collector and the store and if heat is available and needed the pump will switch on, typically when the bottom of the store is 6K - 10K cooler than the collector.

When heat is available, but the store is already at design temperature, there is a risk of stagnation. Some systems will have an additional circuit to reject this heat. Stagnation occurs when the solar system doesn't have anywhere to put the heat that is being collected from the sun. In such conditions flat plate systems can reach temperatures of over 170°C and evacuated tubes over 200°C. At these temperatures in indirect systems, the propylene glycol becomes more acidic and the effectiveness of the glycol to act as an antifreeze will degrade. Closed systems have to be designed to accommodate some boiling (and expansion) using an expansion vessel, or they will release fluid through the safety valve, which can be hazardous and cause a maintenance problem.

When it is expected that systems will be left unattended or unused during periods of high solar insolation appropriate provision for controlling the potentially damaging build-up of heat must be made.

The check valve prevents reverse gravity circulation cooling the water store. This could otherwise occur when the pump is not operating and the collector contains colder, more dense fluid as would be typical at night.

Any pumps in such systems are required by the Building Regulations to consume fewer than 50W, or less than 2% of the peak thermal power of collector, whichever is higher.

== Drainback system ==

The drainback system uses a differential temperature pump controller to compare the temperature in the collector and the store. If heat is available and needed, the pump will switch on. The pump draws liquid from the bottom of the drainback vessel and pumps it up through the top of the solar collectors to return by gravity to the drainback vessel. When the system is not in use or when there is no call for heat, the pump switches off and the water drains from the collectors into the drainback vessel.

[[File:Solar thermal simple drainback.gif|1156x880px|alt=Solar thermal simple drainback.gif]]

Image: A simple drainback system.

Draining back prevents unwanted reverse circulation and overheating and risks from stagnation but is practically limited to residential-sized applications.

The claimed benefits of a drain back system are:
*Gravity is fail-proof and maintenance free.
*Water (or a glycol mixture) may be used in the collector loop.
*The system is not damaged if the pump fails.
*The system cannot reverse thermosyphon at night.
*Collector plates are likely to last longer than in a pressurized glycol system.

However there are also disadvantages:
*Collectors and piping must be above and slope downwards towards the reservoir.
*Larger piping and insulation must be used.
*There are relatively large pumping requirements, especially if the design involves multistory buildings.
*System and pump controls cost approximately 10% of the solar savings (photovoltaic powered pumps are not strong enough).
*Components cost about 10-15% more than a glycol system.
*Systems can be noisy.

== Thermal stores and combi-systems ==

A thermal store will be needed to make solar heating practical. For small residential applications this frequently shares the function of the hot water cylinder. With indirect systems a second coil will be in the lower part of the cylinder to exchange the heat from the solar collectors into the potable domestic hot water.

[[File:Solar thermal store.jpg|213x420px|alt=Solar thermal store.jpg]]

Image: Section through a purpose made solar thermal store.

Larger non-domestic applications will commonly use an additional storage vessel that will act as a preheated feed to the traditional hot water heating system. In the case of a swimming pool installation, the pool itself acts as the thermal store.

Purpose designed thermal stores are becoming increasingly common where the heat from solar panels is used to indirectly preheat water in the store that is then heated directly by the auxiliary heating device (eg a gas boiler).

This water then provides the (non-potable) primary heating water and a coil is immersed in the cylinder to instantaneously provide heat for domestic hot water. These systems are known as 'combisystems' (and more can be read about them on this [http://www.elle-kilde.dk/altener-combi EU project webpage]).

The sizing of the store is as critical as the collectors in ensuring that the maximum benefit is gained from the system. As solar systems become more commonly used, dedicated solar stores (separate from the potable hot water system) are being used in the UK. The size of the associated solar storage tank will depend on the type and frequency of hot water use in the building. Its role is to provide a store for solar heat that is not immediately used by the building. Information from Germany suggests that storage of approximately 50 litres is required per sq m collector area for large-scale installations with reasonably constant weekday use and 60-70 litres per sq m collector area for those where there are consumption free weekdays.

== Factors to consider prior to installation ==

There is a comprehensive list of factors that should be considered prior to installation in the Energy Savings Trust's [http://www.energysavingtrust.org.uk/Publications2/Housing-professionals/Microgeneration-Renewables/Solar-water-heating-systems-guidance-for-professionals-conventional-indirect-models-2006-edition Solar water heating systems – guidance for professionals, conventional indirect models]. These include:
*Occupant’s domestic how water usage pattern.
*Shading. The seasonal influence of trees and local buildings.
*Collector fixing slope and orientation. The limitations of the particular roof, wall or ground fixing.
*Collector fixing area, structure and covering. The methods that may be used to fix the collector.
*Access to collector location, ensuring safe access for installation and servicing.
*Domestic how water heat sources. To confirm that auxiliary heating is able to coexist and work in conjunction with solar thermal.
*Pre-heat storage locations. Ensure that there is the opportunity to integrate appropriate pre-heat facilities (if required).
*Secondary water pressure and quality.

----

[[File:Beslogo150.png|150x85px|alt=Beslogo150.png]]

This article has been reproduced here with the kind permission of the Building & Engineering Services Association. The original article, along with other resources, can be seen on their website: [http://www.b-es.org/ www.b-es.org]

= Find out more =

=== Related articles on Designing Buildings Wiki ===
*Geothermal pile foundations.
*Green Deal.
*Large scale solar thermal energy.
*Solar photovoltaics.
*Wind Energy in the United Kingdom.
*Zero carbon homes.
*Zero carbon non-domestic buildings.

=== External references ===
*BRE [http://www.bre.co.uk/podpage.jsp?id=2983 National Solar Centre].
*B&ES's 'Solar Heating Design and Installation Guide'.
*CIBSE Knowledge Series 15 – 'Capturing solar energy'.
*The B&ES document - SMG 2000 - Standard Maintenance Specification for Services in Buildings provides advice on the maintenance needs of such systems.
*ASHRAE Systems Handbook 2008, Chapter 36.
*ASHRAE Applications Handbook 2007 – Chapter 33: Solar Energy Use.
*Solar Thermal Systems - Successful Planning and Construction' - Felix Peuser et al.
*Department of Energy & Climate Change - [http://www.decc.gov.uk/en/content/cms/meeting_energy/microgen/solar_thermal/solar_thermal.aspx Solar Thermal Water Heating.]
*[http://www.pasolar.ncat.org/lessons.php Solar Refit site.]
*US Department of Energy resource - [http://www.energysavers.gov/your_home/space_heating_cooling/index.cfm?mytopic=12490 Active Solar Heating.]
*[http://canmetenergy-canmetenergie.nrcan-rncan.gc.ca/eng/renewables/solar_thermal.html Natural Resources Canada].
*[http://www.retscreen.net/ang/home.php RETScreen] to determine the benefits of using solar thermal in different locations.
*US based [http://www.wbdg.org/resources/swheating.php Whole Building Design Guide] provides detailed descriptions on solar thermal technologies
*Energy Savings Trust, [http://www.energysavingtrust.org.uk/Publications2/Housing-professionals/Microgeneration-Renewables/Solar-water-heating-systems-guidance-for-professionals-conventional-indirect-models-2006-edition Solar water heating systems – guidance for professionals, conventional indirect models (2006 edition)].
*[http://www.solar-rating.org/commercial/index.html ASHRAE Solar Heating Guidelines].
*Energy Technology List [https://etl.decc.gov.uk/etl/dms/etl/Resources/Technology-Information-Leaflets/ECA770_Solar_Thermal_Tech_B02_02/ECA770%20Solar%20thermal%20technology.pdf Solar thermal technology - A guide to equipment eligible for Enhanced Capital Allowances].
*[http://canmetenergy-canmetenergie.nrcan-rncan.gc.ca/fichier.php/codectec/En/ISBN:0-662-28486-0/SOLAR-BuyersGuide-SolarWaterHeatingSystems_ENG.pdf Solar Water Heating - A Buyer’s Guide]
*[http://www.microgenerationcertification.org/admin/documents/MIS%203001%20Issue%202.0%20Solar%20Heating%202010.08.26.pdf Microgeneration Installation Standard:][http://www.microgenerationcertification.org/admin/documents/MIS%203001%20Issue%202.0%20Solar%20Heating%202010.08.26.pdf MIS3001,]Requirements for Contractors Undertaking The Supply, Design, Installation, Set to Work Commissioning and Handover of Solar Heating Microgeneration Systems Issue 2.0 DECC 2009.
*[http://shop.bsigroup.com/ProductDetail/?pid=000000000000192111 BS5918:1989] Code of practice for solar heating systems for domestic hot water.
*[http://shop.bsigroup.com/ProductDetail/?pid=000000000030216715 BS EN 12975:2006] Thermal solar systems and components.
*[http://www.hse.gov.uk/pubns/books/l8.htm Legionnaires' disease. The control of legionella bacteria in water systems].
*Energy Savings Trust [http://www.energysavingtrust.org.uk/Publications2/Housing-professionals/Microgeneration-Renewables/Solar-water-heating-systems-guidance-for-professionals-conventional-indirect-models-2006-edition Solar water heating systems – guidance for professionals, conventional indirect models (2006 edition)].
*[http://www.planningportal.gov.uk/uploads/br/domestic_building_compliance_guide_2010.pdf DCLG Domestic Building Services Compliance Guide 2010 Edition] includes requirements for collector installations up to 20 sq m and solar heated water storage of less than 440 litres (but only indirect systems).

[[Category:Sustainability]]
[[Category:Products_/_components]]

Performance gap between building design and operation

2014-07-09T10:32:53Z

Susan Poupard:

This article needs more work. To help develop this article, click 'Edit this article' above.

= '''Introduction''' =

There is significant evidence to suggest that buildings do not perform as well as was anticipated at the design stage. The difference between anticipated and actual performance is known as the performance gap.

Findings from the PROBE studies (Post Occupancy Review of Buildings and their Engineering) demonstrated that actual energy consumption in buildings will usually be twice as much as predicted. This was based on post-occupancy reviews of 23 buildings previously featured as ‘exemplar designs’ in the Building Services Journal (BSJ) between 1995 and 2002.

More recent findings from the Carbon Trust‘s Low Carbon Buildings Accelerator and the Low Carbon Buildings Programme have demonstrated that in-use energy consumption can be 5 times higher than compliance calculations.

Both studies suggest that lack of feedback following occupancy is one of the biggest contributors to this gap. Another key factor is that calculations for regulatory compliance do not account for all energy uses in buildings. These calculations are commonly misinterpreted as predictions of in-use energy consumption, when in fact they are simply mechanisms for compliance with the Building Regulations. Unregulated sources of energy consumption such as small power loads, server rooms, external lighting, etc, are rarely considered at design stage. Yet these typically account for more than 30% of the energy consumption in office buildings.

In essence, the performance gap can be regarded as a combination of poor assumptions when predicting energy consumption at design stage (e.g. non-inclusion of unregulated loads, standardised assumptions for occupancy hours and controls) followed by a lack of monitoring post occupation. In other words, current predictions tend to be unrealistically low whilst actual energy demand is typically unnecessarily high (but this is rarely flagged up due to lack of monitoring).

= '''Key issues:''' =
*Buildings typically consume 2 to 5 times more energy than predicted at the design stage.
*Compliance modelling does not account for all energy uses in the building, dealing solely with ‘regulated’ energy loads (fixed building services and internal lighting).
*Designers are rarely required to predict in-use energy consumption.
*Lack of guidance for modelling unregulated energy loads makes it harder for designers to consider these at design stage.
*Lack of feedback regarding the in-use energy performance of buildings is likely to result in an increase in the performance gap.
*Discrepancies between design specification and the works as-built significantly contribute to the gap in performance.
*In order to obtain more accurate predictions, design assumptions must reflect the in-use performance of buildings.

= '''Find out more''' =

=== Related articles on Designing Buildings Wiki ===
*Building regulations.
*BREEAM.
*Code for sustainable homes.
*Computational Fluid Dynamics.
*Emission rates. 
*Energy Savings Opportunity Scheme. 
*Energy performance certificates. 
*Energy Savings Opportunity Scheme.
*Energy targets.
*LEED.
*Soft landings.
*Sustainability.
*Zero carbon homes.
*Zero carbon non-domestic buildings.

=== External references ===
*[http://www.carbonbuzz.org http://www.carbonbuzz.org] 
*[http://www.usablebuildings.co.uk/Pages/UBProbePublications1.html http://www.usablebuildings.co.uk/Pages/UBProbePublications1.html]
*Carbon Trust [http://www.carbontrust.com/resources/guides/energy-efficiency/low-carbon-buildings-design-and-construction Low Carbon Buildings]

[[Category:Articles_needing_more_work]]
[[Category:Regulations]]
[[Category:Sustainability]]

Solar photovoltaics

2014-07-09T10:31:16Z

Susan Poupard:

= Introduction =

Solar cells, or photovoltaic (PV) cells, convert sunlight directly into electricity. Photovoltaics gets its name from the process of converting light (photons) to electricity (voltage). Photovoltaic panels are quite different to solar thermal panels that capture the sun's heat to produce hot water, although some panels now combine both a PV array and a solar thermal collectors.

Rigid photovoltaic cells (traditionally made of silicon) are generally approximately 150mm square and produce a small amount of electricity (at about 0·5 volts). This means that in order to generate a higher voltage, a large number of cells, typically 36 or 72, are connected in series to form a photovoltaic panel. The panels are then connected together to create a photovoltaic array. Generally an array will consist of around 10 panels for a domestic application.

Thin film solar cells use layers of semiconductor materials a few microns thick. Being semi-flexibile they can be used as part of building elements such as roof tiles and glazing systems. New technologies are producing solar cells applied by printing press technologies using solar dyes, and integrated with conductive plastics.

The estimated lifetime of a photovoltaic module is 30 years and performance would be expected to remain at over 80% of the initial power after 25 years.

The carbon footprint of manufacturing photovoltaic has decreased by approximately 50% in the last 10 years due to performance improvements, raw material savings and manufacturing process improvements.

= Transforming sunlight to electricity =

Solar panels are rated in terms of peak power (kWp). This is the potential power output in bright sunlight (1000W/m²) and an air temperature of 25 ºC (the output of panels reduces as they increase in temperature). 1 kWp of well-sited photovoltaic array in the UK should be able to produce 700-800 kWh of electricity per year.

The amount of incident solar radiation will depend on the latitude of the site, the direction that the panels face and the panels tilt angle. An online calculator is available for obtaining estimates of the potential generated energy for sites in Europe (ref EU [http://re.jrc.ec.europa.eu/pvgis/apps4/pvest.php Joint Research Centre]). Even on cloudy days the resulting diffuse light will provide useful electricity, however the performance will be reduced if the site is regularly shaded (for example by adjacent buildings or vegetation).

= Photovoltaic cells =

The are three principle types of photovoltaic cells. Their individual percentage efficiencies indicate how much of the incoming solar radiation will convert into electricity leaving the cell (there will be further losses in the control systems and cabling):
*Monocrystalline: Typical efficiency of 15% (about 100kWh per m² per year in the UK). These are typically dark coloured with close lines of thin conductors.
*Polycrystalline: Typical efficiency of at least 13% (around 100kWh per m² per year in the UK). These are likely to have a truly crystalline appearance.
*Thin film: Typical efficiency of 7% (about 60kWh per m² per year in the UK). These may be integrated onto brise-soleil, roof tiles or glass panels.

Crystalline photovoltaics currently account for over 90% of installed systems.

The cost of the materials is generally highest for the more efficient types of cell although the integration of thin-film technologies into building elements adds to their cost.

= Using the energy from photovoltaics =

Photovoltaics can power systems that are totally disconnected from the grid (particularly in rural locations) however the surge in interest in UK applications is for grid-connected systems that are eligible for government funding. This allows any excess power produced to be sold to the electrical supply company, and provides a normal grid supply to the premises when there is insufficient photovoltaic generation.

= Photovoltaic installation =

There is relatively little mechanical work associated with the installation of photovoltaic panels, and there is a mature market for the supply of flexible mounting systems. However, there is controlled work that requires properly trained electricians, and installation of roof-mounted panels would normally require a trained 'roofing' installer. Photovoltaic modules generate electricity whenever they are exposed to daylight and individual modules cannot be switched off so, unlike most other electrical installations, installing a photovoltaic system involves working on a live system.

Typical installations of photovoltaic modules will weigh 10–13 kg/m².The main types of installation are:
*Roof or wall mounting of framed photovoltaics. The photovoltaics are mounted in framing that should generally protrude less than 200mm to satisfy normal planning requirements.
*Roof or wall-integrated photovoltaics, where the panel is a weathered section of the surface.
*Roof slates and tiles. These will be more expensive as individual components but may reduce expenditure by displacing standard tiles/slates.
*Surface-mounted (thin-film) photovoltaics. Semi-flexible thin-film photovoltaics are attached to a building component such as a glass panel or flat roof.
*Framed installations (freestanding or attached to building). Plastic or metal frames can sit on roofs or on the ground to provide optimum tilt and orientation.

More recent developments have led to a variety of forms of integrated solar collector, including:
*Solar shingles mounted flat on boarded roofs.
*Solar slates mounted on battens that can replace standard roof components.
*Solar glass laminates, where the photovoltaics take the form of semi-transparent glazing.

These can offer opportunities to include photovoltaics in a project where, previously, aesthetic considerations would have prevented their use.

In a grid connected system, DC power from the photovoltaic modules is fed into an inverter for conversion to 240 V AC power for connection to the local electricity network through the consumer unit. Ideally, the inverter (or 'power control unit') will be sited close to the panels to reduce DC transmission losses (it needs ventilation and may hum). In larger applications several inverters may be used to provide improved resilience against failure. The inverter unit will normally control the connection of the photovoltaic system to the grid (as well as to the building loads). If there is a mains power outage the inverters automatically switch off to protect any engineers working on the power lines.

In off-grid systems the DC power is fed into a charge controller before being supplied to a storage medium, such as lead acid batteries. A grid-connected solar photovoltaic system requires no batteries. Specialised solutions may be used to provide hybrid systems allowing grid-based systems to work safely off-grid (in combination with batteries), but normally, systems designed for the grid are not usable directly with battery storage.

Photovoltaic systems do not generally require special precautions for lightning protection although taking precautions against lightning and excess voltage may be advisable to protect the investment in the photovoltaics.

A recent report from the International Energy Agency (IEA) [http://www.iea-pvps.org/ Photovoltaic Power Systems Programme] set out the life expectancy of equipment associated with a photovoltaic installations:
*Photovoltaic panels: 30 years for mature module technologies.
*Inverters: 15 years for small plants (residential photovoltaics).
*Structures: 30 years for roof-tops and façades, and between 30 to 60 years for ground mounted installations on metal supports.
*Cabling: 30 years.

The BRE’s [http://www.bre.co.uk/page.jsp?id=859 UK Photovoltaic Domestic Field Trial] in 2006 showed that for fairly small system sizes of around 1.6kWp, a significant fraction of the building demand can be met by the photovoltaic system with the majority of systems providing between 20 and 80% of the building annual load, with an average of 51%.

= Planning and Regulation =

In the UK, fixing solar panels to a single dwelling house that is not a listed building and is not in a conservation area is considered to be a ‘permitted development’ and so there is no need to apply for planning permission. Photovoltaic installations are however notifiable for building regulations purposes and the local building control authority should be informed.

The District Network Operator (DNO) must be consulted about connection to the local grid (and an agreement put in place) although normally systems of up to 16 amps per phase can be installed without asking permission of the DNO. Extensive guidance on the electrical requirements is given in the DTI publication: [http://www.bre.co.uk/filelibrary/pdf/rpts/Guide_to_the_installation_of_PV_systems_2nd_Edition.pdf Photovoltaics in buildings: guide to the installation of PV systems].

The Microgeneration Certification Scheme (MCS) has provided [http://www.microgenerationcertification.org/installers/installers/installer-standards Microgeneration Installation Standard: MIS 3002] that guides the design and installation of photovoltaics. This is essential if government funding is being sought for a project of less than 50kW and provides a useful source of information for larger installations.

= '''Government Funding''' =

Photovoltaic installations are recognised as a small-scale (less than 5MW) 'renewable energy' technology by the UK Government. As such they attract Feed in Tariff payments (FITs) for installations up to 5MW for a duration of 25 years. Microgeneration systems (less than 50kW) must be installed under the auspices of the MCS to attract funding.

Feed in Tariffs consist of 2 elements:
*Generation tariff. A payment for each unit (kWh) of electricity generated.
*Export tariff. Electricity that is not used on site can be exported back to the grid and a payment is paid as an additional payment (on top of the generation tariff).

If photovoltaics are installed and the property owner/operator receives Feed in Tariffs, and subsequently the property is passed to another owner, the Feed in Tariffs will remain with the installation and accrue to the new owner.

If a business has photovoltaics installed and is already involved in the Carbon Reduction Commitment (CRC) Energy Efficiency Scheme the output from photovoltaic systems (that are registered for Feed in Tariffs) will not be counted as 'zero emission' for CRC purposes but must be accounted for at the grid average. To use photovoltaics to gain CRC credit, Feed in Tariffs cannot be claimed. Detailed guidance on the Feed in Tariff scheme for businesses is available in some clearly written fact sheets on the [http://www.carbontrust.com/resources/guides/renewable-energy-technologies/renewable-energy-and-combined-heat-and-power-(chp) Carbon Trust website].

----

[[File:Beslogo150.png|150x85px|alt=Beslogo150.png]]

This article has been reproduced here with the kind permission of the Building & Engineering Services Association. The original article, along with other resources, can be seen on their website: [http://www.b-es.org/ www.b-es.org]

= Find out more =

=== Related articles on Designing Buildings Wiki ===
*Carbon Reduction Commitment.
*Geothermal energy.
*Green Deal.
*Large scale solar thermal energy.
*Solar thermal systems.
*Zero carbon homes.
*Zero carbon non-domestic buildings.

=== External references ===
*BRE [http://www.bre.co.uk/podpage.jsp?id=2983 National Solar Centre]. 
*[https://www.cibseknowledgeportal.co.uk/search.html?st=TM25 CIBSE TM25 Understanding Building Photovoltaics] provides a comprehensive reference in the design and application of PV.
*BRE's 8 page [http://www.hvcapublications.co.uk/Ecommerce/ID/102/Product/HeatPumpGuide/Details.aspx Information Paper 8/11] Photovoltaic Systems on Dwellings - Key Factors For Successful Installations, provides one of the most concise guides for PV application in the UK.
*[https://www.bsria.co.uk/bookshop/books/heat-pumps-a-guidance-document-for-designers/ BSRIA BG 1/2008 - Renewable Technologies] has a short section on PVs
*[http://www.nef.org.uk/renewableenergy/photovoltaics.htm National Energy Foundation] have an excellent set of pages covering many aspects of PVs.
*[http://www.energysavingtrust.org.uk/Generate-your-own-energy/Solar-panels-PV Energy Saving Trust] has a page with up to date guidance and links to appropriate legislation and government web resources as well as a [http://www.google.co.uk/url?sa=t&rct=j&q=buyers%20guide%20to%20solar%20electricity&source=web&cd=3&ved=0CIwBEBYwAg&url=http%3A//www.energysavingtrust.org.uk/Publications2/Generate-your-own-energy/A-buyer-s-guide-to-solar-electricity-panels&ei=BYEuT7zsB4S48gPw2vjMCw&usg=AFQjCNESRWAXC1rUqsccUlDAd4th6SQF8A&sig2=p9vVUIuff_fOa7zdnrTRPQ Buyers Guide to Solar Electricity].
*[http://www.yoursunyourenergy.com/ Your Sun Your Energy] produced by the [http://www.epia.org/ European Photovoltaic Industry Association (EPIA)] and the European Commission's [http://www.eupvplatform.org/ European Photovoltaic Technology Platform.]
*EPIA: [http://www.epia.org/publications/epia-publications/solar-generation-6.html Solar photovoltaic electricity empowering the world 2011].
*The [http://re.jrc.ec.europa.eu/pvgis/apps4/pvest.php EC's Photovoltaic Geographical Information System] (PVGIS) provides detailed estimations of the annual electricity yield from a PV installation.
*[http://www.iea-pvps.org/ IEA Photovoltaic Power Systems Programme (PVPS)] has relevant downloads including: [http://www.iea-pvps.org/index.php?id=3&eID=dam_frontend_push&docID=999 Review of the life cycle assessment of PV (Report IEA-PVPS T12-03:2011 November 2011)].
*[http://www.decc.gov.uk/en/content/cms/meeting_energy/microgen/solar_pv/solar_pv.aspx Department of Energy & Climate Change - DECC Solar PV Resource].
*The US DoE [http://www.energysavers.gov/your_home/electricity/index.cfm/mytopic=10710 Small Scale Solar Systems].
*The Carbon Trust [http://www.carbontrust.com/media/81357/ctg038-a-place-in-the-sun-photovoltaic-electricity-generation.pdf Solar PV].
*The DTI [http://www.bre.co.uk/filelibrary/pdf/rpts/Guide_to_the_installation_of_PV_systems_2nd_Edition.pdf Guide to the installation of PV systems] provides extensive electrical installation details.
*[http://www.solar-trade.org.uk/ Solar Trade Association]. A well-established trade organisation with some resources.
*[http://www.bpva.org.uk/ British Photovoltaic Association]. A relatively new manufacturer and installers based organisation that provides a growing resource of materials.

[[Category:Sustainability]]
[[Category:Products_/_components]]

UK construction industry

2014-07-09T10:28:46Z

Susan Poupard:

= Introduction =

Construction is a very diverse industry that includes activities ranging from mining, quarrying and forestry to the construction of infrastructure and buildings, the manufacture and supply of products, as well as maintenance, operation and disposal.

Construction output in the UK is more than £110 billion per annum and contributes 7% of GDP (ref [https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/61152/Government-Construction-Strategy_0.pdf Government Construction Strategy]). Approximately a quarter of construction output is public sector and three quarters private sector (ref [http://www.ons.gov.uk/ons/publications/re-reference-tables.html?edition=tcm:77-295369 Office for National Statistics 2012]).

There are three main sectors (ref [https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/61152/Government-Construction-Strategy_0.pdf Government Construction Strategy]):
*Commercial and social (approximately 45%)
*Residential (approximately 40%)
*Infrastructure (approximately 15%)

Approximately 60% of construction output is new build, whilst 40% is refurbishment and maintenance (ref [http://www.ons.gov.uk/ons/publications/re-reference-tables.html?edition=tcm:77-295369 Office for National Statistics 2012]).

The industry accounts for approximately 3 million jobs, 10% of total UK employment (ref Construction 2025) and includes both manufacturing and services. According to the Department for Business Innovation and Skills, the industry is made up as follows:
*Contracting, 2,030,000 jobs, 234,000 businesses. 
*Services, 580,000 jobs, 30,000 businesses. 
*Products, 310,000 jobs, 18,000 businesses.

Ref BIS, [https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/210060/bis-13-958-uk-construction-an-economic-analysis-of-sector.pdf UK Construction, An economic analysis of the sector], July 2013.

Construction is a high cost, high risk, long term activity, and so it is often a good indicator of the heath of the wider economy. When the economy falters, construction investment grinds to a halt, but when the economy begins to recover, the construction industry can quickly overheat.

= Leadership and governance =

Construction comes within the remit of the Department of Business, Innovation and Skills. However, planning and building regulations fall under the Department for Communities and Local Government. To further confuse matters, the Government Construction Board chaired by the Chief Construction Adviser reports to the Minister for the Cabinet Office and the Cabinet Office is also the home of the Efficiency and Reform Group which includes the Major Projects Authority.

In addition, a Construction Leadership Council (CLC) was established in 2013 to oversee implementation of Construction 2025: industrial strategy for construction. This is an industry / government council jointly chaired by the Secretary of State for Business, Innovation and Skills and an industry representative (at present Sir David Higgins, Chief Executive of Network Rail).

Other organisations also have involvement in the governance of construction:
*British Waterways Board.
*Civil Aviation Authority.
*Design Council CABE.
*English Heritage.
*English Nature.
*Environment Agency.
*Health and Safety Executive.
*Highways Agency.
*Local authorities.
*Port of London Authority.

See Statutory consultees and Non-statutory consultees for more information.

In addition, the industry has established numerous boards, councils, institutes and associations to lobby, develop, promote and regulate construction activities:
*Building Services Research and Information Association (BSRIA)
*Chartered Institute of Building (CIOB)
*Chartered Institution of Building Services Engineers (CIBSE)
*Constructing Excellence (CE)
*Construction Industry Research and Information Association (CIRIA)
*Construction Industry Training Board (CITB)
*Construction Products Association (CPA)
*Construction Project Information Committee (Cpic)
*Institution of Civil Engineers (ICE)
*Institution of Structural Engineers (Istructe)
*National Building Specification (nbs)
*Royal Institute of British Architects (RIBA)
*Royal Institution of Chartered Surveyors (RICS)
*Royal Town Planning Institute (RTPI)
*UK Contractors Group (UKCG)

= Criticism =

The UK construction industry is regularly criticised for being wasteful, adversarial, fragmented, dominated by single disciplines, reluctant to innovate and poor at disseminating knowledge (See Construction industry reports for more information). However, given that despite a great number of reports about the industry, and numerous attempts to improve efficiency, the perception or poor performance persists, it might be inferred either that; under the circumstances the industry operates more effectively than it appears from the outside; expectations are unrealistic; or recommendations have been consistently poorly implemented.

= Challenges =

The UK construction industry faces a number of very serious challenges:

== Urbanisation ==

In 1900, only 13% of the population lived in urban areas. Over half of the planet's population now lives in cities. These densely occupied areas should be more sustainable than more dispersed rural settlements, but in fact they account for more than 75% of the consumption of non-renewable resources, and create around three quarters of global pollution.

By the second half of the century, more than 70% of us will live in cities, and at the same time global population will increase from 7 billion to around 9.5 billion. If we are to accommodate this growth whilst at the same time reducing overall consumption, our design and construction needs to become much smarter. See Smart Cities for more information.

== Climate change and sustainability ==

The UK government has committed to cut green house gas emissions by 80% by 2050 compared to 1990 levels, and to halve them by 2025. In 2009 buildings accounted for about 43% of all the UK’s carbon emissions (ref [https://www.gov.uk/government/policies/improving-the-energy-efficiency-of-buildings-and-using-planning-to-protect-the-environment DCLG]). If the government commitment is to be met, our buildings must become considerably more efficient. This is made more complicated by the fact that over 80% of the UK building stock that will exist in 2025 has already been built.

Not only does our building stock need to become more efficient, if the climate changes as projected, it will also need to become more resilient.

== Government construction strategy ==

The Government Construction Strategy has set in motion two major initiatives:
*An intention to achieve savings of 15 to 20% by the end of the parliament.
*A requirement for fully-collaborative 3D BIM on all centrally-procured construction contracts by 2016.

See [[Government_construction_strategy|Government Construction Strategy]] for more information.

== Performance gap ==

There is significant evidence to suggest that buildings do not perform as well in practice as was anticipated at the design stage. The difference between anticipated and actual performance is known as the performance gap.

Findings from the PROBE studies (Post Occupancy Review of Buildings and their Engineering) demonstrated that actual energy consumption in buildings will usually be twice as much as predicted. More recent findings from the Carbon Trust‘s Low Carbon Buildings Accelerator and the Low Carbon Buildings Programme have demonstrated that in-use energy consumption can be 5 times higher than compliance calculations.

See [[Performance_gap|performance gap]] for more information.

= Procurement =

Typically a construction project will involve a funder, a client, consultants, a contractor, sub-contractors and suppliers. They will generally be procured following one of the five main procurement routes:
*Traditional contract.
*Design and build.
*Construction management.
*Management contract.
*Public procurement.

For more possibilities see: Procurement routes.

A typical traditional contract will include the following stages:
*Stage 1: [[Traditional%20contract%3A%20business%20justification|Business justification]].
*Stage 2: [[Traditional%20contract%3A%20feasibility%20studies|Feasibility studies]].
*Stage 3: [[Traditional%20contract%3A%20project%20brief|Project brief]].
*Stage 4: [[Traditional%20contract%3A%20concept%20design|Concept design]].
*Stage 5: [[Traditional%20contract%3A%20detailed%20design|Detailed design]].
*Stage 6: [[Traditional%20contract%3A%20production%20information|Production information]].
*Stage 7: [[Traditional%20contract%3A%20tender|Tender]].
*Stage 8: [[Traditional%20contract%3A%20mobilisation|Mobilisation]].
*Stage 9: [[Traditional%20contract%3A%20construction|Construction]].
*Stage 10: [[Traditional%20contract%3A%20occupation%20and%20defects%20liability%20period|Occupation and defects liability period]].
*Stage 11: [[Traditional%20contract%3A%20post%20occupancy%20evaluation|Post occupancy evaluation]].

= Find out more =

=== Related articles on Designing Buildings Wiki ===
*Building regulations.
*Construction 2025.
*Construction industry reports.
*Construction industry institutes and associations.
*Construction Leadership Council.
*Government construction strategy.
*Non-statutory consultees.
*Performance gap.
*Planning permission.
*Procurement route.
*Smart cities.
*Statutory consultees.
*Sustainability.
*UK.

=== External references ===
*BIS, [https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/210060/bis-13-958-uk-construction-an-economic-analysis-of-sector.pdf UK Construction, An economic analysis of the sector], July 2013.
*The Carbon Trust, [http://www.carbontrust.com/news/2012/02/building-a-lower-carbon-construction-industry-(1) Building a lower carbon construction industry]

[[Category:Articles_needing_more_work]]
[[Category:History]]
[[Category:Public_procedures]]

Biomass

2014-07-09T09:57:25Z

Susan Poupard:

= Introduction =

Biomass is a generic term referring to organic materials that can be used as fuels. Biomass differs from fossil fuels because of the timescale required for replacement. Whilst both take carbon out of the environment during their creation, before releasing it when used as a fuel, fossil fuels deplete faster than they are replaced and so are not sustainable whereas biomass can be replaced relatively quickly and so may be considered ‘carbon neutral’.

Solid bioenergy options include woodchips and pellets. Using these types of biomass fuel as a heating source is well established across Europe and the UK. The use of biomass as an energy source is traditionally through combustion within a biomass boiler, providing hot water. This technology can be a central boiler supplying heat via district heating or individual biomass stoves or boilers in each property.

Biomass fuel can also be used to generate power through Combined Heat and Power (CHP) technology. Small scale biomass CHP systems are in development, but they are still considered to be an emerging technology. The specific requirements of a biomass CHP system are similar to a biomass boiler, with the notable difference being additional space requirements, particularly height.

= Technical Information =
*The following figures can be used to determine the approximate storage area required (the actual volume will depend on the moisture content of the fuel):
#Pellets: 3,000 kWh/m³ fuel
#Chips: 800 kWh/m³ fuel
*Storing more than 2 months supply is not recommended because of potential problems with decay and fungal growth.
*Five litres of combustion ash is produced by each of the following:
#1,000 litres of wood pellets
#15 litres of wood chips
*Attention must be paid to chimney heights. Biomass boilers have to be certified as 'clean' for smoke controlled zones.
*Exhaust gases are cleaner than those from oil-fired boilers.
*Feeding systems for boilers greater than 2MW becomes more complicated and requires moving floors etc.

= Loading =

Generally biomass systems should be sized lower than peak loads as these occur infrequently. The [http://www.carbontrust.com/resources/tools/biomass-decision-support-tool/ Carbon Trust] has developed a sophisticated tool for sizing boilers and storage requirements.

Biomass boilers turndown (the amount by which heat output can be reduced from the maximum without switching off) is usually 20-30% on dry fuel and 40% on wet fuel. This dictates sizing unless a buffer tank is used.

Commonly a gas/oil back up boiler (or burner) will be specified to provide fuel resilience in case of supply chain problems, this boiler can also be used to ‘top-up’ to a peak load capacity. An exception to this might be small domestic applications where fitting two boilers may be uneconomic. Typically a biomass boiler sized at around 30-40% peak load will supply 60-70% of heating consumption over a year..

= Wood Resources =

In 2007, The [http://www.forestry.gov.uk/pdf/fce-woodfuel-strategy.pdf/$FILE/fce-woodfuel-strategy.pdf Woodfuel Strategy for England] estimated that there was a resource of 3.5 million tonnes of green wood per annum, with a potential for 5.5 million tonnes by 2020.

However, some members of the AECB (The Association for Environment Conscious Building) are against biomass (see [https://magellan2.burohappold.com/sites/knowledge/WikiPlus%20Documents/AECB%20discussion%20paper%20on%20biomass.pdf AECB discussion paper on biomass]) on the basis that wood used in boilers could otherwise be used in other wood products that don't release CO2 into the atmosphere. This caused a lot of heated debate and many members felt that the AECB had taken a position on the issue without consulting its members. One such discussion can be found [http://www.greenbuildingforum.co.uk/forum114/comments.php?DiscussionID=6241 here].

In July 2013, the UK government appeared to turn away from biomass when it capped subsidies for bespoke biomass burning plants and announced that it would end subsidies for biomass burning in existing stations by 2027. This followed a [http://www.bbc.co.uk/news/business-23334466 report from the BBC] revealing that millions of tonnes of wood were being shipped from the USA to help meet Britain's renewables targets.

= Air Quality Management =

In general, cities must monitor their air quality, and if certain emission are above advisory thresholds they must implement an Air Quality Management Plan (AQMP). It is possible that where there is an AQMP, part of this plan might be to limit biomass installations. However, air quality is predominately a function of diesel powered transport and so it could be argued that restricting biomass boilers is not tackling the root of the problem.

NB Waste wood and other wastes in the UK fall under the [http://www.defra.gov.uk/industrial-emissions/eu-international/wid/ Waste Incineration Directive] (WID) and require expensive treatment to reduce harmful emissions.

----

This article was created by --[[User%3ABuro%20Happold|Buro Happold]].

= Find out more =

=== Related articles on Designing Buildings Wiki ===
*Combined heat and power (CHP). 
*Forests.
*Geothermal energy.
*Large scale solar thermal energy
*Solar photovoltaics.
*Solar thermal systems.
*Timber.

=== Externals references. ===
*[http://www.woodheatsolutions.eu/event.aspx?id=548 Wood fuel solutions training CD download] - useful reference point for all aspects of biomass installations.
*[https://www.cibseknowledgeportal.co.uk/component/dynamicdatabase/?layout=publication&revision_id=140 Barbour Intranet Login].
*The Carbon Trust [http://www.carbontrust.com/resources/guides/renewable-energy-technologies/biomass-heating-tools-and-guidance Biomass heating tools and guidance]
*[http://www.biomassenergycentre.org.uk/pls/portal/docs/PAGE/RESOURCES/REF_LIB_RES/PUBLICATIONS/UKBIOMASSSTRATEGY.PDF Defra - UK Biomass Strategy (PDF)].
*[http://www.biomassenergycentre.org.uk/portal/page?_pageid=73,1&_dad=portal&_schema=PORTAL The Biomass Energy Centre (BEC) - part of the Forestry Commision].
*[http://www.r-p-a.org.uk/home.fcm Renewable Energy Association].
*[http://www.caddet.org/technologies/index.php DET (Centre for Analysis and Dissemination for Demonstrated Energy Technologies) - Technologies].
*The [http://sylva.org.uk/ Sylva Foundation] conduct wood based research and have a tool for estimating wood resource in forests. This is connected to a sort of social network/market place for biomass.
*[http://www.biomassenergycentre.org.uk/portal/page?_pageid=77,225275&_dad=portal&_schema=PORTAL Biomass Energy Centre].
*[http://www.bigbarn.co.uk/logpile/indexen.php Logpile].
*[http://www.southwestwoodshed.co.uk/static/ South West Wood Shed].

[[Category:Sustainability]]
[[Category:Products_/_components]]

Biomass

2014-07-09T09:57:01Z

Susan Poupard:

= Introduction =

Biomass is a generic term referring to organic materials that can be used as fuels. Biomass differs from fossil fuels because of the timescale required for replacement. Whilst both take carbon out of the environment during their creation, before releasing it when used as a fuel, fossil fuels deplete faster than they are replaced and so are not sustainable whereas biomass can be replaced relatively quickly and so may be considered ‘carbon neutral’.

Solid bioenergy options include woodchips and pellets. Using these types of biomass fuel as a heating source is well established across Europe and the UK. The use of biomass as an energy source is traditionally through combustion within a biomass boiler, providing hot water. This technology can be a central boiler supplying heat via district heating or individual biomass stoves or boilers in each property.

Biomass fuel can also be used to generate power through Combined Heat and Power (CHP) technology. Small scale biomass CHP systems are in development, but they are still considered to be an emerging technology. The specific requirements of a biomass CHP system are similar to a biomass boiler, with the notable difference being additional space requirements, particularly height.

= Technical Information =
*The following figures can be used to determine the approximate storage area required (the actual volume will depend on the moisture content of the fuel):
#Pellets: 3,000 kWh/m³ fuel
#Chips: 800 kWh/m³ fuel
*Storing more than 2 months supply is not recommended because of potential problems with decay and fungal growth.
*Five litres of combustion ash is produced by each of the following:
#1,000 litres of wood pellets
#15 litres of wood chips
*Attention must be paid to chimney heights. Biomass boilers have to be certified as 'clean' for smoke controlled zones.
*Exhaust gases are cleaner than those from oil-fired boilers.
*Feeding systems for boilers greater than 2MW becomes more complicated and requires moving floors etc.

= Loading =

Generally biomass systems should be sized lower than peak loads as these occur infrequently. The [http://www.carbontrust.com/resources/tools/biomass-decision-support-tool/ Carbon Trust] has developed a sophisticated tool for sizing boilers and storage requirements.

Biomass boilers turndown (the amount by which heat output can be reduced from the maximum without switching off) is usually 20-30% on dry fuel and 40% on wet fuel. This dictates sizing unless a buffer tank is used.

Commonly a gas/oil back up boiler (or burner) will be specified to provide fuel resilience in case of supply chain problems, this boiler can also be used to ‘top-up’ to a peak load capacity. An exception to this might be small domestic applications where fitting two boilers may be uneconomic. Typically a biomass boiler sized at around 30-40% peak load will supply 60-70% of heating consumption over a year..

= Wood Resources =

In 2007, The [http://www.forestry.gov.uk/pdf/fce-woodfuel-strategy.pdf/$FILE/fce-woodfuel-strategy.pdf Woodfuel Strategy for England] estimated that there was a resource of 3.5 million tonnes of green wood per annum, with a potential for 5.5 million tonnes by 2020.

However, some members of the AECB (The Association for Environment Conscious Building) are against biomass (see [https://magellan2.burohappold.com/sites/knowledge/WikiPlus%20Documents/AECB%20discussion%20paper%20on%20biomass.pdf AECB discussion paper on biomass]) on the basis that wood used in boilers could otherwise be used in other wood products that don't release CO2 into the atmosphere. This caused a lot of heated debate and many members felt that the AECB had taken a position on the issue without consulting its members. One such discussion can be found [http://www.greenbuildingforum.co.uk/forum114/comments.php?DiscussionID=6241 here].

In July 2013, the UK government appeared to turn away from biomass when it capped subsidies for bespoke biomass burning plants and announced that it would end subsidies for biomass burning in existing stations by 2027. This followed a [http://www.bbc.co.uk/news/business-23334466 report from the BBC] revealing that millions of tonnes of wood were being shipped from the USA to help meet Britain's renewables targets.

= Air Quality Management =

In general, cities must monitor their air quality, and if certain emission are above advisory thresholds they must implement an Air Quality Management Plan (AQMP). It is possible that where there is an AQMP, part of this plan might be to limit biomass installations. However, air quality is predominately a function of diesel powered transport and so it could be argued that restricting biomass boilers is not tackling the root of the problem.

NB Waste wood and other wastes in the UK fall under the [http://www.defra.gov.uk/industrial-emissions/eu-international/wid/ Waste Incineration Directive] (WID) and require expensive treatment to reduce harmful emissions.

----

This article was created by --[[User%3ABuro%20Happold|Buro Happold]].

= Find out more =

=== Related articles on Designing Buildings Wiki ===
*Combined heat and power (CHP). 
*Forests.
*Geothermal energy.
*Large scale solar thermal energy
*Solar photovoltaics.
*Solar thermal systems.
*Timber.

=== Externals references. ===
*[http://www.woodheatsolutions.eu/event.aspx?id=548 Wood fuel solutions training CD download] - useful reference point for all aspects of biomass installations.
*[https://www.cibseknowledgeportal.co.uk/component/dynamicdatabase/?layout=publication&revision_id=140 Barbour Intranet Login].
*The Carbon Trust [http://www.carbontrust.com/resources/guides/renewable-energy-technologies/biomass-heating-tools-and-guidance Biomass heating tools and guidance]
*[http://www.biomassenergycentre.org.uk/pls/portal/docs/PAGE/RESOURCES/REF_LIB_RES/PUBLICATIONS/UKBIOMASSSTRATEGY.PDF Defra - UK Biomass Strategy (PDF)].
*[http://www.biomassenergycentre.org.uk/portal/page?_pageid=73,1&_dad=portal&_schema=PORTAL The Biomass Energy Centre (BEC) - part of the Forestry Commision].
*[http://www.r-p-a.org.uk/home.fcm Renewable Energy Association].
*[http://www.caddet.org/technologies/index.php DET (Centre for Analysis and Dissemination fo Demonstrated Energy Technologies) - Technologies].
*The [http://sylva.org.uk/ Sylva Foundation] conduct wood based research and have a tool for estimating wood resource in forests. This is connected to a sort of social network/market place for biomass.
*[http://www.biomassenergycentre.org.uk/portal/page?_pageid=77,225275&_dad=portal&_schema=PORTAL Biomass Energy Centre].
*[http://www.bigbarn.co.uk/logpile/indexen.php Logpile].
*[http://www.southwestwoodshed.co.uk/static/ South West Wood Shed].

[[Category:Sustainability]]
[[Category:Products_/_components]]

Project benchmarking

2014-07-09T09:53:49Z

Susan Poupard:

Benchmarking is a process by which the estimated performance (often cost) of a project is compared to other similar projects. This can highlight areas of design that are not offering good value for money and can help in the assessment of tenders from suppliers and contractors.

Benchmarking is increasingly being carried out on public projects, where the government has access to large amounts of cost data for similar projects. For example, when analysis of the recent schools programme was carried out, it was found that it '... exposed variations in costs that could not be justified by project differences' ([http://www.cabinetoffice.gov.uk/resource-library/government-construction-strategy Cabinet Office: Government Construction Strategy], May 2011).

It is now proposed that cost benchmarking should be carried out across all government capital programmes to create baselines for a cost/value-led approach to procurement.

In the private sector, comparable cost information may not be so readily available. However, large organisations may have access to in-house cost information, and some cost information is published. Comparative information can also be purchased from sources such as the [http://www.bcis.co.uk/site/index.aspx Building Cost Information Service (BCIS).]See [http://www.bcis.co.uk/site/scripts/retail_product_browse.aspx?product_id=791&category_id=11 BCIS Online] for a description of the tender price and duration information available.

It is important however that benchmarking does not simply consider construction costs, as these are only a small proportion of whole-life costs, and setting a low benchmark for construction could result in higher operating, maintenance and refurbishment costs throughout the life of the building.

There is now an increasing amount of data available about energy use, sustainability and whole-life costs such as:
*[http://www.carbonbuzz.org/ CarbonBuzz,] an on-line service that allows architects and engineers to share project forecasts and energy use anonymously.
*The Carbon Trust [http://www.carbontrust.com/resources/faqs/sector-specific-advice/energy-benchmarking Energy Benchmarking]
*[http://www.cibse.org The Chartered Institute of Building Services Engineers].
*[http://www.breeam.org/page.jsp?id=66 Building Research Establishment Environmental Assessment Method (BREEAM)].
*[http://www.cibse.org/index.cfm?go=publications.view&item=288 Closing the Loop – Benchmarks for Sustainable Buildings (RIBA)].

It is important also to consider both quality and time, as the lowest cost option may not always offer the best value for the client or deliver a completed project within the required timeframe.

= Find out more =

=== Related articles on Designing Buildings Wiki ===
*Additionality.
*Business case.
*Design review.
*Design quality.
*Earned value analysis.
*Key performance indicators.
*Value management techniques.
*Whole-life costs.

=== External references. ===
*[http://www.cabinetoffice.gov.uk/resource-library/government-construction-strategy Government construction strategy], Page 11.
*[http://www.bcis.co.uk/site/scripts/retail_product_browse.aspx?product_id=791&category_id=11 BCIS online tools].

[[Category:Cost_/_business_planning]]
[[Category:Design]]

CRC Energy Efficiency Scheme

2014-07-09T09:51:49Z

Susan Poupard:

The CRC Energy Efficiency Scheme was introduced in 2008 as the 'Carbon Reduction Commitment' (CRC). The Scheme itself began in April 2010 with the introduction of the CRC Energy Efficiency Scheme Order 2010. It forms part of the UK's commitment to reduce greenhouse gas emissions by at least 80% from 1990 levels by 2050.

The Scheme is slowly being phased in throughout the UK, and in England and Wales is being administered by the Environment Agency.

The Scheme aims to encourage energy efficiency and a reduction in carbon dioxide emissions in large public and private sector organisations. It does this by introducing financial and reputational incentives.

The Scheme covers large non-energy-intensive organisations within the UK's public and private sector such as:
*Supermarkets.
*Hotels.
*Water companies.
*Banks.
*Local authorities.
*Government departments.

These large non-energy-intensive organisations account for about 10 per cent of the UK’s carbon dioxide emissions.

The Scheme does not cover energy-intensive businesses such as power generation, cement, glass, pulp and paper industries which are already covered by other forms of emissions trading and climate change levy schemes.

Qualification for the scheme is based on the amount of electricity consumed by an organisation. Organisations that had at least one half hour meter in 2008 were required to make an information disclosure in 2010. Organisations with at least one half hour meter and whose electricity consumption was at least 6,000 MWh in 2008 are required to participate fully in the scheme.

Where businesses are part of a larger organisation, they must take part in the scheme together under their highest parent organisation.

Participating organisations are required to monitor and report their energy use each year and to purchase allowances equal to their annual emissions in tonnes of CO2 during each compliance year from 2011/12 onwards.

The total allowances cost for each year is calculated by multiplying by the quantity of CO2 emissions in tonnes, as submitted in the organisations annual report, by the cost per allowance set by HM Treasury. For 2011/12 and 2012/13, this will be £12 per tonne.

From 2013/14 it is intended that the total number of allowances will be capped, and that rather than being sold at a fixed price, allowances will be auctioned.

The scheme was originally intended to be revenue-neutral, meaning that all the money raised from selling allowances would be distributed back to participants, with the highest-ranking organisations in the league table receiving larger distributions. However in 2010, the government decided instead to retain the revenues generated. This resulted in considerable lobbying against the scheme, and a result, a consultation process is now underway to try to consider how the scheme might be simplified.

= Find out more =

=== Related articles on Designing Buildings Wiki ===
*Climate Change Act.
*Climate Change Levy.
*Emission rates.
*Energy Act.
*Energy certificates.
*Energy related products regulations.
*Energy targets.
*Green Deal.
*Sustainability.
*Zero carbon non-domestic buildings.

=== External references ===
*Environment Agency: [http://publications.environment-agency.gov.uk/PDF/GEHO0312BWGE-E-E.pdf CRC Energy Efficiency Scheme: Guidance for participants in Phase 1 (2010/11–2013/14)]
*Business Link: [http://www.businesslink.gov.uk/bdotg/action/layer?r.i=1086680026&r.l1=1079068363&r.l2=1086029607&r.l3=1086679098&r.s=m&r.t=RESOURCES&topicId=1086679098 CRC guide].
*SOMARL [http://www.somar.co.uk/carbon-trust/CRC-energy-efficiency.php?Pageid=113 Guide to the CRC Energy Efficiency Scheme].
*Carbon Trust: [http://www.carbontrust.com/resources/reports/footprinting/carbon-reduction-commitment CRC Energy Efficiency Scheme].
*DECC: [http://www.decc.gov.uk/en/content/cms/emissions/crc_efficiency/crc_efficiency.aspx CRC Energy Efficiency Scheme].
*[http://www.decc.gov.uk/en/content/cms/emissions/crc_efficiency/simplification/simplification.aspx DECC consultation process].

[[Category:Other_legislation]]
[[Category:Sustainability]]
[[Category:Client_procedures]]

Energy targets for buildings

2014-07-09T09:50:23Z

Susan Poupard:

According to the [https://www.innovateuk.org/built-environment Technology Strategy Board], in the UK, the built environment accounts for 45% of total carbon emissions (27% from domestic buildings and 18% from non-domestic), and 73% of domestic emissions arise from space heating and the provision of hot water.

Minimum standards for the conservation of fuel and power are set out in Part L of the Building Regulations. Part L sets standards intended to:
*Limit heat losses and gains.
*Provide efficient, effectively controlled and properly commissioned building services.
*Provide the building owner with information allowing them to operate the building efficiently.

In order to achieve this the regulations and associated approved documents set out the following criteria: 
*The designed carbon emission rate (Dwelling Emission Rate (DER) for self-contained dwellings and individual flats (excluding common areas) and Building Emission Rate (BER) for buildings other than dwellings) must not exceed the Target Emission Rate (TER) for a notional building of similar type, size and shape.
*Fixed building services should achieve a reasonable standard of energy efficiency. This is intended to prevent inappropriate trade-offs between different elements of the building. Minimum limiting parameters are set for key components of the building fabric to ensure that this is the case.
*Solar gains should be limited.
*As-built performance should be consistent with the DER. This includes air-permeability testing and appropriate commissioning of building services systems.
*Provision should be made for energy efficient operation by providing the building owner with information enabling them to operate the building in a way that uses no more fuel and power than is reasonable. This might be done by the preparation of a building log book.

These requirements are becoming more demanding as the government pushes towards its goal of requiring that all new dwellings are 'zero carbon' rated by 2016, and that all new non-domestic buildings are zero carbon from 2019. See Zero carbon homes, and Zero carbon non-domestic buildings for more information. 

However, it should be noted that energy predictions are not accurate. For example, they tend not to properly factor in occupant behaviour (such as the use of a great deal of electronic equipment, and the tendency not to switch things off when predicted) and so often fall short of the energy consumption of buildings in reality. See performance gap for more information. It is hoped that the roll out of Display Energy Certificates and the introduction of benchmarking services such as [http://www.carbonbuzz.org/ CarbonBuzz] should help make predictions more accurate.

Clients may wish to exceed statutory requirements, and set their own energy targets. Perhaps they have existing standards which they would like to apply to the new development, they may wish to create an exemplar development, or they may simply wish to reduce running costs. Such targets should be established during the early stages of the project by the designers and the client so that they can be properly incorporated into the design and included in tender documentation. Energy targets need to be considered throughout the design process, from fuel appraisal investigations right through to window to wall ratios, floor to floor heights, slab thicknesses and insulation.

There are also a number of standards and accreditations that can be used to set energy targets such as:
*BREEAM.
*[http://www.passivhaus.org.uk/ Passivhaus].
*The Code for Sustainable Homes.

In addition to the requirements of the Building Regulations, the National Planning Policy Framework makes clear that there should be a presumption in favour of granting planning permission for sustainable developments, this might include low-energy or low-carbon developments.

Schemes such as the CRC Energy Efficiency Scheme and the Energy Related Products Regulations have also been introduced to help encourage energy efficiency, and government initiatives such as the Green Deal, Feed in Tariff, Renewable Heat Incentive and the Climate Change Levy have introduced financial incentives.

= Find out more =

=== Related articles on Designing Buildings Wiki ===
*Building log book.
*CRC Energy Efficiency Scheme.
*Demolition.
*Emission rates.
*Energy Act.
*Energy certificates.
*Energy Related Products Regulations. 
*Energy Savings Opportunity Scheme.
*Green Deal.
*National Planning Policy Framework.
*Performance gap.
*Sustainability.

=== External references. ===
*[http://www.breeam.org/ Building Research Establishment Energy Assessment Method] (BREEAM)].
*[http://www.cibseenergycentre.co.uk/energy-certificates/energy-performance-certificates-epcs.html CIBSE Energy performance certificates.]
*[http://www.cibse.org/index.cfm?go=page.view&item=847 CIBSE example structure for an energy policy.]
*[http://www.planningportal.gov.uk/buildingregulations/approveddocuments/partl/ Building Regulations: Approved document L2A.]
*[http://www.cibse.org/index.cfm?go=publications.view&item=6 CIBSE Guide F: Energy Efficiency in Buildings.]
*[http://webarchive.nationalarchives.gov.uk/20100503135839/http://www.ogc.gov.uk/assets/images/pace_rob.pdf PACE requirements for office buildings.]
*[http://www.communities.gov.uk/publications/planningandbuilding/displayenergycertificates Department for communities and local government, display energy certificates.]
*[http://www.cibseenergycentre.co.uk/energy-certificates/energy-performance-certificates-epcs.html CIBSE Energy centre, energy performance certificates.]
*Carbon Trust, [http://www.carbontrust.com/resources/guides/energy-efficiency/low-carbon-buildings-design-and-construction Low Carbon Buildings] & [http://www.carbontrust.com/resources/guides/energy-efficiency/buildings-energy-efficiency Buildings energy efficiency].
*[http://www.passivehouse-international.org/ Passivehaus passipedia.]

[[Category:Regulations]]
[[Category:Sustainability]]
[[Category:Design]]

Environmental legislation for building design and construction

2014-07-09T09:47:18Z

Susan Poupard:

This article summarises UK environmental legislation relating to buildings design and development. In some cases, there will be alternative legislation in Scotland, Wales and Northern Ireland.

= Primary Legislation (Acts or Orders) =
*Agricultural Land (Removal of Surface Soil) Act.
*Clean Air Act.
*Clean Neighbourhoods and Environment Act.
*Climate Change Act.
*Energy Act.
*Environment Act.
*Environmental Protection Act.
*Flood and Water Management Act.
*Localism Act.
*Natural Environment and Rural Communities Act.
*Protection of Badgers Act.
*Water Act.
*Water Resources Act.
*Wildlife and Countryside Act.

= Secondary Legislation (Regulations) =
*Building Regulations.
*Conservation of Habitats and Species Regulations.
*Contaminated Land (England) Regulations.
*Control of Asbestos Regulations.
*Control of Noise (Codes of Practice for Construction and Open Sites) (England) Order.
*Control of Substances Hazardous to Health Regulations.
*Controlled Waste Regulations Energy Efficiency (Refrigerators and Freezers) Regulations.
*Energy Performance of Buildings (Certificates and Inspections) (England and Wales) Regulations.
*Energy Related Products Regulations.
*Environmental Permitting (England and Wales) Regulations.
*Environmental Protection (Controls on Ozone-Depleting Substances) Regulations.
*Fluorinated Greenhouse Gas Regulations.
*Hazardous Waste (England and Wales) Regulations.
*Notification of Cooling Towers and Evaporative Condensers Regulations.
*Packaging (Essential Requirements) Regulations.
*Site Waste Management Plan Regulations.
*Town and Country Planning (environmental impact assessment) (England and Wales) Regulations.
*Waste (England and Wales) Regulations.
*Waste Management Licensing Regulations.
*Waste Management (England and Wales) Regulations.
*Volatile Organic Compounds in Paints, Varnishes and Vehicle Refinishing Products Regulations.

= Policy =

NB this list is not comprehensive and requires further work.
*CRC Energy Efficiency Scheme.
*National Planning Policy Framework.
*Zero carbon homes.
*Zero carbon non-domestic buildings.
*National Waste Management Plan for England.
*Green deal.
*Renewable Heat Incentive.
*Feed-In Tariff scheme (FIT).
*Carbon Emissions Reduction Target (CERT).

= Find out more =

=== Related articles on Designing Buildings Wiki ===
*BREEAM.
*Code for Sustainable Homes.
*CRC Energy Efficiency Scheme.
*Emission rates.
*Energy Performance Certificates.
*Energy Related Products Regulations. 
*Energy Savings Opportunity Scheme ESOS.
*Energy targets.
*Environmental Impact Assessment.
*Flood and Water Management Act.
*Green deal.
*LEED.
*Localism Act.
*National Planning Policy Framework.
*Statutory authorities.
*Statutory obligations.
*Sustainability.
*Sustainable materials.
*Zero carbon homes.
*Zero carbon non-domestic buildings.

=== External references ===
*NetRegs: [http://www.environment-agency.gov.uk/netregs/legislation/current/default.aspx Environmental Legislation].
*[http://www.environment-agency.gov.uk Environment Agency].
*[http://www.defra.gov.uk/ Department for Environment, Food and Rural Affairs].

[[Category:Articles_needing_more_work]]
[[Category:Health_and_safety_/_CDM]]
[[Category:Other_legislation]]
[[Category:Regulations]]
[[Category:Sustainability]]

Environmental legislation for building design and construction

2014-07-09T09:46:46Z

Susan Poupard:

This article summarises UK environmental legislation relating to buildings design and development. In some cases, there will be alternative legislation in Scotland, Wales and Northern Ireland.

= Primary Legislation (Acts or Orders) =
*Agricultural Land (Removal of Surface Soil) Act.
*Clean Air Act.
*Clean Neighbourhoods and Environment Act.
*Climate Change Act.
*Energy Act.
*Environment Act.
*Environmental Protection Act.
*Flood and Water Management Act.
*Localism Act.
*Natural Environment and Rural Communities Act.
*Protection of Badgers Act.
*Water Act.
*Water Resources Act.
*Wildlife and Countryside Act.

= Secondary Legislation (Regulations) =
*Building Regulations.
*Conservation of Habitats and Species Regulations.
*Contaminated Land (England) Regulations.
*Control of Asbestos Regulations.
*Control of Noise (Codes of Practice for Construction and Open Sites) (England) Order.
*Control of Substances Hazardous to Health Regulations.
*Controlled Waste Regulations Energy Efficiency (Refrigerators and Freezers) Regulations.
*Energy Performance of Buildings (Certificates and Inspections) (England and Wales) Regulations.
*Energy Related Products Regulations.
*Environmental Permitting (England and Wales) Regulations.
*Environmental Protection (Controls on Ozone-Depleting Substances) Regulations.
*Fluorinated Greenhouse Gas Regulations.
*Hazardous Waste (England and Wales) Regulations.
*Notification of Cooling Towers and Evaporative Condensers Regulations.
*Packaging (Essential Requirements) Regulations.
*Site Waste Management Plan Regulations.
*Town and Country Planning (environmental impact assessment) (England and Wales) Regulations.
*Waste (England and Wales) Regulations.
*Waste Management Licensing Regulations.
*Waste Management (England and Wales) Regulations.
*Volatile Organic Compounds in Paints, Varnishes and Vehicle Refinishing Products Regulations.

= Policy =

NB this list is not comprehensive and requires further work.
*CRC Energy Efficiency Scheme.
*National Planning Policy Framework.
*Zero carbon homes.
*Zero carbon non-domestic buildings.
*National Waste Management Plan for England.
*Green deal.
*Renewable Heat Incentive.
*Feed-In Tariff scheme (FIT).
*Carbon Emissions Reduction Target (CERT).

= Find out more =

=== Related articles on Designing Buildings Wiki ===
*BREEAM.
*Code for Sustainable Homes.
*CRC Energy Efficiency Scheme. 
*Energy Savings Opportunity Scheme ESOS.
*Emission rates.
*Energy Performance Certificates.
*Energy Related Products Regulations.
*Energy targets.
*Environmental Impact Assessment.
*Flood and Water Management Act.
*Green deal.
*LEED.
*Localism Act.
*National Planning Policy Framework.
*Statutory authorities.
*Statutory obligations.
*Sustainability.
*Sustainable materials.
*Zero carbon homes.
*Zero carbon non-domestic buildings.

=== External references ===
*NetRegs: [http://www.environment-agency.gov.uk/netregs/legislation/current/default.aspx Environmental Legislation].
*[http://www.environment-agency.gov.uk Environment Agency].
*[http://www.defra.gov.uk/ Department for Environment, Food and Rural Affairs].

[[Category:Articles_needing_more_work]]
[[Category:Health_and_safety_/_CDM]]
[[Category:Other_legislation]]
[[Category:Regulations]]
[[Category:Sustainability]]

Daylight lighting systems

2014-07-09T09:43:03Z

Susan Poupard:

= Introduction =

Government initiatives such as zero carbon homes and zero carbon non-domestic buildings mean that the construction industry needs to find ways to reduce the energy consumption of buildings.The definition of 'zero carbon' homes focusses on net carbon emissions from regulated energy devices, namely those used for space heating and cooling, water heating and lighting.

'Natural' daylight systems may be one way of contributing to these reductions in carbon emissions.

= Daylight systems =

Daylight systems collect natural light and deliver deep into the heart of buildings. They use collectors in the roof to harvest light, then transport it to diffusers into interior spaces. The quality of this natural light tends to be alive and vibrant, and diffusers can be placed strategically to allow the best distribution of light within the interior.

There are four main types of daylighting system:
*Tubular daylight devices.
*Vertical systems.
*Horizontal systems.
*Fibre optical devices.

= Tubular Daylight Devices =

Also called TDDs, tubular daylight devices consist of a fixed ocular that collects light from the roof of a building and directs it into a tubular 'pipe' lined with a highly-reflective surface. The light is reflected down the tube by this surface to diffusers in the interior of the building that direct it into occupied spaces. (See [http://www.solatube.co.uk/ Solatube] for an example of a tubular daylight system)

This system has many advantages:
*It has no mechanical parts.
*It is relatively inexpensive.
*It can harvest relatively low levels or light.
*Tubes can be as small as 10 inches in diameter, meaning they can easily be run through the walls.

Disadvantages include, the need for one ocular per tube, and a significant loss of light beyond 10 metres ( that is to say it is only practical to transport light up to 3 floors ), or where there is a change of direction in the tube.

= Vertical Systems =

Vertical systems are very similar to TDDs, but they use a powered tracking system to point a light 'collector' towards the sun, and a series of mirrors and lenses that concentrate the light before directing it into distributing tubes.

As a result, much more light can be collected, and it can be delivered 3 to 7 times deeper into the building than would be possible with TDD's. However a 60cm opening is required in the roof, and the system is relatively inexpensive. (See [http://www.sundolier.com/ Sundolier] for an example of a vertical daylight system)

= Horizontal systems =

Horizontal systems use lenses to collect natural light from external walls and transport it through flat light ducts above the ceiling to diffusers placed deep inside the building (see [http://www.suncentralinc.com/technology/our-solution/ SunCentral] for an example of a horizontal daylight system). They make use of a polymer material that combines a high reflectivity with the practicality of a hollow duct similar to a ventilation duct.

Horizontal systems are a fairly recent development and as such are relatively untested and expensive.

= Fibre Optical =

Fibre optical systems collect light with mirrors and lenses which track the sun and transport it into a buildings interior through fibre optic cables (see [http://www.parans.com/eng/sp3/ Parans] for an example of a fibre optical system). As fibre optic cables are relatively flexible, they can be installed in a similar way to electric cables and can be 'bent' in any direction (above a minimum 50mm radius). They also require little space, meaning they can deliver light almost anywhere in a building. Diffusers can be replaced by point lights.

However, fibre optical systems harvest predominately direct (rather than diffuse) light and tend to be expensive.

----

This article was created by --[[User%3AJose%20P.R.|Jose Poyan]] 18:25, 1 December 2012 (UTC)

= Find out more =

=== Related articles on Designing Buildings Wiki ===
*Geothermal pile foundation.
*Rainwater harvesting.
*Sustainability.
*Zero carbon homes.
*Zero carbon non-domestic buildings.

=== External references. ===
*AIA: [http://www.aia.org/practicing/AIAB096065 Advanced Daylighting Technologies].
*[http://www.monodraught.com/ http://www.monodraught.com/]
*[http://www.solatube.com/ http://www.solatube.com/]
*[http://www.commonsenseuk.co.uk/index.php?page=Home http://www.commonsenseuk.co.uk/index.php?page=Home]
*[http://www.sundolier.com/ http://www.sundolier.com/]
*[http://www.suncentralinc.com/company/overview/ http://www.suncentralinc.com/company/overview/]
*[http://www.parans.com/eng/ http://www.parans.com/eng/]

[[Category:Sustainability]]
[[Category:Products_/_components]]

Energy Savings Opportunity Scheme ESOS

2014-07-08T16:43:00Z

Susan Poupard:

Energy audits can be carried out on buildings or across organisations to assess their energy use and propose measures that might be taken to reduce energy consumption.

Article 8 of the European Union (EU) Energy Efficiency Directive (2012/27/EU), requires that member states introduce regular energy audits for large enterprises with more than 250 employees or turnover exceeding €50m (that is, enterprises other than small and medium-sized enterprises (SMEs)). This is intended to encourage the uptake of cost-effective energy-efficiency measures. These audits must be undertaken by 5 December 2015, and then every four years after that. The scheme does not extend to public bodies and does not require that energy saving measures reccomended as a result of an audit are actually implemented.

In the UK, the government believes this offers significant opportunities for improving competitiveness and contributing to growth. They propose the directive should be implemented through an Energy Savings Opportunity Scheme (ESOS).

The Department of Energy & Climate Change has carried out a [https://www.gov.uk/government/consultations/energy-savings-opportunity-scheme consultation] on how best to implement the scheme and is considering the feedback received. The consultation proposes that as a minimum, assessments must:
*Be carried out by and approved ESOS assessor.
*Review the total energy use and energy efficiency of the organisation.
*Recommend cost-effective measures to save energy and money.

The government intends that the ESOS will:
*Provide high-quality and well-targeted advice.
*Ensure a proportionate approach to implementation, minimising the administrative burden.
*Ensure the ESOS compliments existing energy efficiency and climate change policy.
*Avoids ‘gold plating’ that disadvantages UK businesses.

= Find out more =

=== Related articles on Designing Buildings Wiki ===
*BREEAM.
*Climate Change Act.
*Code for sustainable homes.
*Energy audit.
*Emission rates.
*Energy targets.
*Energy performance certificates.
*Green deal.
*Performance gap. 
*LEED.
*Sustainability.
*Zero carbon homes.
*Zero carbon non-domestic buildings.

=== External references. ===
*Department of Energy & Climate Change, [https://www.gov.uk/government/consultations/energy-savings-opportunity-scheme Energy Savings Opportunity Scheme].
*Carbon Trust, [http://www.carbontrust.com/esos ESOS: UK Energy Savings Opportunity Scheme]

[[Category:Other_legislation]]
[[Category:Sustainability]]

Wind energy

2014-07-08T16:41:32Z

Susan Poupard:

This article needs more work. To help develop this article, click 'Edit this article' above.

= Introduction =

The scientific community has warned that there is an urgent need for a transition to a low carbon economy if we are to avert a global catastrophe due to climate change.

The concentration of CO2 in the atmosphere reached 400ppm in 2014, up from 280ppm in pre-industrial times, corresponding to 375,000,000,000 tonnes of CO2 released into the atmosphere since 1750.

Wind is a clean, plentiful renewable energy source.

The UK has relatively good and easily exploited wind resources:
*It has 40% of Europe’s wind due to its position in the North West of Europe where it bears the full brunt of weather systems coming in from the North Atlantic.
*It has the longest coastline in Europe (the island of Great Britain has a coastline of 17,820 km according to the Ordnance Survey).
*It has many shallow waters, ideal for off-shore wind.
*It has many sparsely populated upland areas, mainly in the North which is also the region with the most significant wind resources.

Wind is the most developed renewable energy source in the UK.

= Wind installations in the UK =

The first British wind farm was established in 1991 at Delabole, Cornwall. Since then, largely due to the government's Renewables Obligation, UK wind energy capacity has flourished.

There are currently (Dec 2012) 361 projects live in the UK, which equates to 4,136 turbines, 5,054 MW of on-shore capacity and 2,679 MW off-shore capacity, i.e. a total of 7,7733MW.

The United Kingdom was the world leader in off-shore wind in 2012. 

[[File:Installed wind capacity UK.JPG|RTENOTITLE]] 

= Public perception of wind power =

There are some vocal opposition groups to wind power who object to new wind farms being built in their area, claiming that they are noisy, a danger to wildlife and a blight on the countryside.

However, by and large, the British view wind power in a favourable light. In surveys carried out in 2012 for RenewablesUK, the body which champions UK wind and marine energy, and for the Sunday Times, it emerged that:
*77% of Britons are in favour of electricity from renewables.
*73% of Britons support offshore wind and 66% onshore wind installations.
*Only 17% of Britons support additional gas/coal power stations.
*Only 40% of Britons support additional nuclear power stations.

= Advantages and disadvantages of wind power =

== Advantages ==
*The main advantage is the low carbon nature of wind power. It is a completely 'clean' energy, other than the manufacture and construct on of the pylons, blades and turbines.
*Wind power generation is relatively silent.
*The wind is strongest in the winter months when energy demand is at its highest.
*Many jobs are created in designing, manufacturing, and servicing the equipment.

 Analysis from the Carbon Trust suggests offshore wind has the potential to deliver significant benefits to the UK, including:*A 7% reduction in UK carbon emissions versus 1990
*A quarter of a million UK jobs by 2050
*Annual revenues of some £19 billion by 2050

== Disadvantages ==
*The main disadvantage is the unpredictable nature of wind speeds resulting in turbines being immobile for significant periods.
*It is difficult to store generated power.
*Wind turbines tend to be large and very visible within the countryside.

= International Comparisons =

== Worldwide ==

There was 250 GW installed capacity worldwide in 2012. The UK ranks 8th in the world for installed capacity, however on a per-capita basis the UK is not in the top 20.

The 8 countries with the most installed capacity are (2011 figures, GW):
*China (62.4)
*USA (46.9)
*Germany (29.1)
*Spain (21.7)
*India (15.9)
*Italy (6.7)
*France (6.6)
*United Kingdom (6.5)

== Europe ==

The UK had the 5th largest installed capacity in Europe at the end of 2011; this reflects its fairly late uptake of wind power compared for example with Germany, which has by far the most capacity, or Spain.

Installed capacity in Europe, end of 2011 (MW)

{| cellspacing="0" cellpadding="0" border="1"
|-
|
Ger

|
Spain

|
France

|
Italy

|
UK

|
Port

|
Den

|
Swe

|
NL

|-
|
29,060

|
21,674

|
6,800

|
6,747

|
6,540

|
4,083

|
3,871

|
2,907

|
2,328

|}

Germany had the largest new installed capacity in Europe in 2011 (2,100 MW) with the UK following at 1,300 MW, of which 752 MW was offshore wind. Spain came third (1,050 MW) and then France (830 MW).

= Find out more =

=== Related articles on Designing Buildings Wiki ===
*Energy Act.
*Geothermal pile foundations.
*Ground energy options.
*Large scale solar thermal energy.
*Rainwater harvesting.
*Sustainability.
*Solar photovoltaics.
*Solar thermal energy.

=== External references ===
*[http://www.decc.gov.uk/ www.decc.gov.uk] Department of Energy and Climate Change
*[http://www.renewableuk.com/ http://www.renewableuk.com], the “The UK's leading renewable energy trade association”
*[http://www.ewea.org/fileadmin/files/library/publications/statistics/Wind_in_power_2011_European_statistics.pdf http://www.ewea.org] European Wind Energy Association 
*Carbon Trust [http://www.carbontrust.com/offshorewind Offshore Wind Accelerator]
*[http://www.wmo.int/ http://www.wmo.int] World Meteorological Organization

[[Category:Articles_needing_more_work]]
[[Category:Sustainability]]
[[Category:Products_/_components]]

Wind energy

2014-07-08T16:40:47Z

Susan Poupard:

This article needs more work. To help develop this article, click 'Edit this article' above.

= Introduction =

The scientific community has warned that there is an urgent need for a transition to a low carbon economy if we are to avert a global catastrophe due to climate change.

The concentration of CO2 in the atmosphere reached 400ppm in 2014, up from 280ppm in pre-industrial times, corresponding to 375,000,000,000 tonnes of CO2 released into the atmosphere since 1750.

Wind is a clean, plentiful renewable energy source.

The UK has relatively good and easily exploited wind resources:
*It has 40% of Europe’s wind due to its position in the North West of Europe where it bears the full brunt of weather systems coming in from the North Atlantic.
*It has the longest coastline in Europe (the island of Great Britain has a coastline of 17,820 km according to the Ordnance Survey).
*It has many shallow waters, ideal for off-shore wind.
*It has many sparsely populated upland areas, mainly in the North which is also the region with the most significant wind resources.

Wind is the most developed renewable energy source in the UK.

= Wind installations in the UK =

The first British wind farm was established in 1991 at Delabole, Cornwall. Since then, largely due to the government's Renewables Obligation, UK wind energy capacity has flourished.

There are currently (Dec 2012) 361 projects live in the UK, which equates to 4,136 turbines, 5,054 MW of on-shore capacity and 2,679 MW off-shore capacity, i.e. a total of 7,7733MW.

The United Kingdom was the world leader in off-shore wind in 2012. 

[[File:Installed wind capacity UK.JPG|RTENOTITLE]] 

= Public perception of wind power =

There are some vocal opposition groups to wind power who object to new wind farms being built in their area, claiming that they are noisy, a danger to wildlife and a blight on the countryside.

However, by and large, the British view wind power in a favourable light. In surveys carried out in 2012 for RenewablesUK, the body which champions UK wind and marine energy, and for the Sunday Times, it emerged that:
*77% of Britons are in favour of electricity from renewables.
*73% of Britons support offshore wind and 66% onshore wind installations.
*Only 17% of Britons support additional gas/coal power stations.
*Only 40% of Britons support additional nuclear power stations.

= Advantages and disadvantages of wind power =

== Advantages ==
*The main advantage is the low carbon nature of wind power. It is a completely 'clean' energy, other than the manufacture and construct on of the pylons, blades and turbines.
*Wind power generation is relatively silent.
*The wind is strongest in the winter months when energy demand is at its highest.
*Many jobs are created in designing, manufacturing, and servicing the equipment.
 Analysis from the Carbon Trust suggests offshore wind has the potential to deliver significant benefits to the UK, including:*A 7% reduction in UK carbon emissions versus 1990
*A quarter of a million UK jobs by 2050
*Annual revenues of some £19 billion by 2050

== Disadvantages ==
*The main disadvantage is the unpredictable nature of wind speeds resulting in turbines being immobile for significant periods.
*It is difficult to store generated power.
*Wind turbines tend to be large and very visible within the countryside.

= International Comparisons =

== Worldwide ==

There was 250 GW installed capacity worldwide in 2012. The UK ranks 8th in the world for installed capacity, however on a per-capita basis the UK is not in the top 20.

The 8 countries with the most installed capacity are (2011 figures, GW):
*China (62.4)
*USA (46.9)
*Germany (29.1)
*Spain (21.7)
*India (15.9)
*Italy (6.7)
*France (6.6)
*United Kingdom (6.5)

== Europe ==

The UK had the 5th largest installed capacity in Europe at the end of 2011; this reflects its fairly late uptake of wind power compared for example with Germany, which has by far the most capacity, or Spain.

Installed capacity in Europe, end of 2011 (MW)

{| cellspacing="0" cellpadding="0" border="1"
|-
|
Ger

|
Spain

|
France

|
Italy

|
UK

|
Port

|
Den

|
Swe

|
NL

|-
|
29,060

|
21,674

|
6,800

|
6,747

|
6,540

|
4,083

|
3,871

|
2,907

|
2,328

|}

Germany had the largest new installed capacity in Europe in 2011 (2,100 MW) with the UK following at 1,300 MW, of which 752 MW was offshore wind. Spain came third (1,050 MW) and then France (830 MW).

= Find out more =

=== Related articles on Designing Buildings Wiki ===
*Energy Act.
*Geothermal pile foundations.
*Ground energy options.
*Large scale solar thermal energy.
*Rainwater harvesting.
*Sustainability.
*Solar photovotaics.
*Solar thermal energy.

=== External references ===
*[http://www.decc.gov.uk/ www.decc.gov.uk] Department of Energy and Climate Change
*[http://www.renewableuk.com/ http://www.renewableuk.com], the “The UK's leading renewable energy trade association”
*[http://www.ewea.org/fileadmin/files/library/publications/statistics/Wind_in_power_2011_European_statistics.pdf http://www.ewea.org] European Wind Energy Association 
*Carbon Trust [http://www.carbontrust.com/offshorewind Offshore Wind Accelerator]
*[http://www.wmo.int/ http://www.wmo.int] World Meteorological Organization

[[Category:Articles_needing_more_work]]
[[Category:Sustainability]]
[[Category:Products_/_components]]

Optimising your article for search engines

2014-07-08T16:31:47Z

Susan Poupard:

[[File:DBWHeader.jpg|468x91px|alt=DBWHeader.jpg]]

Most people come to articles on Designing Buildings Wiki straight from Google. To make sure your article attracts a lot of readers, you need it to come as high as possible in search results. This isn't complicated. Google is designed to find things that users want, so all you have to do is make it clear your article provides things users want.

----
*Make sure the title of your article is a phrase that people are likely to search for. A good trick for finding out what people search for is to start typing your title into google and see what it predicts you are trying to find – then use that for your title.
*Don't make your title too general. The title 'Appointing consultants' could relate to any industry, 'Appointing consultants for construction projects' is more self-explanatory and likely to rank higher in search results.
*Make sure you repeat key phrases people are likely to search for throughout your article.
*Don’t use acronyms. If your article is about ground source heat pumps, write ground source heat pumps not GSHP. Nobody searches for acronyms.
*Link your article to other sources of information.
*Create links to your article from other sites. You can do this by adding links from your own website, or by posting links on social media.
*If your article is really long, think about breaking it up into several shorter articles. This can help build a critical mass about your subject.
*Add images to your article and put phrases people are likely to search for in the image description. If the only information you provide about your image is that it's pict2001344.jpg, Google (and readers of your article) are not going to know what it is.
*Keep improving your article. Articles that were last edited in 2001 will have slipped down the search results no matter how good they are.

----

That’s it. It’s really not complicated but it makes a huge difference.

----

[[File:Global community grey.jpg|1500x525px|alt=Global community grey.jpg]]

[[Category:Site_Information]]

Search engine optimisation

2014-07-08T16:25:46Z

Susan Poupard:

To help develop this article, click 'Edit this article' above.

----

Search engine optimisation (SEO) is the process of improving the visibility of a website or web page in a search engine's 'natural' or 'organic' (rather than paid for) search results. The higher and more frequently a site appears in search results, the more visitors it is likely to receive.

This is increasingly important as search engines become the default method for finding information.

The construction industry is dominated by people searching for a wide range of knowledge and a great number of products with which to create buildings. There are approximately 250,000 companies operating in the construction industry in the UK. Appearing first when potential clients are searching for particular products or services is critical to business success.

SEO considers how search engines work, what people search for, the actual search terms or keywords typed into search engines and what sort of search engines are preferred by a particular targeted audience.

Optimising a website so that it appears higher and more frequently in search results may involve:
*Writing content that is useful to the target audience.
*Writing content that includes frequently searched for keyword phrases.
*Providing people writing for the website with clear instructions about which keywords must be included and giving an indication of the number of times each keyword should be included.
*Using synonyms to the key topic words to allow a broader range of search topics to direct people to the site.
*Captioning images so that search engines can index them appropriately.
*Giving videos titles using appropriate keywords.
*Writing appropriate meta descriptions - the short text that appears when your website come up in search results.
*Ensuring that individual pages stick to one subject and that page tags are on the same topic.
*Regularly editing content to so that search engines keep re-indexing it.
*Increasing the number of ‘backlinks’ (inbound links).
*Creating internal links and site maps that make it easier for search engines to direct people to the most important pages on the site.
*Linking to other relevant sites. This not only affects the ranking of a site, but may encourage other site owners to link back to it in return.
*Allowing visitors to favourite and share the website and web pages using social media.
*Ensuring pages include data, statistics and graphs as people like to share this sort of content.
*Avoiding placing content behind registration forms or pay walls. Search engines prefer content that can be accessed freely, and they cannot always index information behind forms and walls. If access restrictions are necessary, make sure some portions of the site remain visible, such as page titles for example.

Targeted SEO can focus on specific kinds of search, such as; image searches, local searches, video searches, academic searches, industry-specific searches and so on. SEO for international markets may require translation, registration of local domain names and web hosting that provides a local IP address.

The most popular search engines (Google, Bing, and Yahoo) do not disclose the algorithms they use to rank pages and these algorithms are changed continually. For example, in 2011 Google implemented a new system to penalise sites whose content is not unique. In 2012, a further update was released, down-grading websites that provided poor user experience.

Companies that employ overly aggressive techniques (‘black hat’ techniques such as; including hidden pages or hidden text or creating pages with excessive or irrelevant keywords) can be 'banned' from the search results. For example in 2006 Google temporarily removed BMW Germany from its search results.

Once a website has been optimised so that the highest possible number of people are directed to it, it is important that those people find high quality, engaging web pages that encourage them to stay on the site and browse more than one page.

= Find out more =

=== Related articles on Designing Buildings Wiki ===
*Brand guidelines.
*Getting published.
*Writing technique.

[[Category:Articles_needing_more_work]]