Last edited 18 Nov 2020

Energy audit

Energy audits are undertaken to assess energy use and propose measures that might be taken to reduce consumption and costs.

The Carbon Trust suggest that 20% of business' annual energy costs are wasted by energy inefficient equipment, however, businesses often focus on revenue rather than costs and so 60% of cost-effective, viable, energy efficiency recommendations are not implemented. (Ref Carbon Trust, Mandatory energy efficiency audits for business. December 2013.)

An energy audit might be undertaken for a single building, several buildings, a site or an organisation, and might be carried out for commercial or domestic clients.

An energy audit might provide:

An assessment of energy consumption and carbon emissions.
A comparison with previous audits.
Benchmarking against similar buildings.
Assessment in relation to corporate energy targets or policies.
A schedule of energy savings that could be made.
An Investment appraisal of proposed measures including pay-back periods.
An assessment of the difficulty of implementation.
Prioritisation of measures.
Proposed changes to operations, staff behaviour, communications, training and so on.
Potential suppliers.
Financing options.

Typically, savings might be identified through assessment of:

Whether buildings are being operated properly (in accordance with the intention of the original design). For example, occupants opening windows in air-conditioned buildings.
Whether changes been made since buildings were completed prevent them from operating properly (such as changes to plant during repairs or servicing).
The type of lighting.
Type and management of heating and cooling.
Thermal comfort.
Monitoring systems, timers, controls, sensors and other devices.
Industrial processes, plant, equipment and machinery.
Building fabric, heat loss, air-tightness and insulation.
Type of energy used and tariff.
Potential to use low-carbon or renewable energy.
Potential for on-site energy generation.
Possible behavioral changes.
Assessment of other issues such as; water consumption, waste streams and transport.

Energy audits can be carried out in-house if there is sufficient expertise, or external advisers (such as energy surveyors) may be appointed. Organisations such as the Carbon Trust provide accreditation for energy surveyors.

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 a turnover exceeding €50m (ie 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 businesses implement the energy saving recommendations.