Last edited 19 Jun 2017



In Spring 2017, a consortium was formed to prove the effectiveness of a new smart biotechnological filter at tackling urban air pollution.

Green City Solutions, Proambiente and the Italian city of Modena joined forces to initiate the ‘CityTree Scaler’; a project enabled by the support of Climate-KIC Germany (the biggest EU innovation initiative for climate-friendly technologies).

The aim of the two-year research project is to provide cities with a holistic solution of a smart climate infrastructure, while attempting to tackle air pollution, improve biodiversity and reduce the urban heat island effect.


The consortium have installed six CityTrees in the most polluted street in Modena. Developed by German start-up, Green City Solutions, CityTrees combine cutting-edge internet of things (IoT) technology with moss cultures and plants that ‘eat’ air pollution. They report that CityTree has the same environmental impact as 275 urban trees but requires only 3 sq. m of space – 99% less.

The sculptural structures contain plants capable of removing dust, nitrogen dioxide and ozone from low-lying smog. The units are also remarkably self-sufficient. Due to the IoT technology which uses sensors to measure environmental data, solar panel technology, and a rainwater collecting system, the nutrition, water and minerals required by the plants can be automatically regulated, meaning they only require a few hours of maintenance a year.


The results of the project are expected to prove that each CityTree offsets 240 tonnes of CO2 equivalents a year, resulting in a CO2 equivalents reduction by the 6 units of approximately 2.880 tons over the 2-year period.

WiFi, iBeacon, NFC and digital screens also allow CityTrees to transmit digital and visual information, and companies can pay to advertise on them by adding lighting, logos or LED panels.

The technology behind the CityTree is a result of more than a decade’s research at the Dresden University of Technology, Lancaster University and University of Bonn. CityTrees have already appeared in many European cities, and installations are planned in Hong Kong, Oslo, Paris, Skopje, Dresden and Hannover.

Victor Splittgerber, CTO and co-founder of Green City Solutions, said: “The project will help us to obtain important insights of the effectiveness of our smart plant filters. The results will help us to prove the estimated results of the laboratory tests. We see the CityTree as an essential part of future environmental urban planning. Therefore the next logical step is the testing over a longer period under real urban conditions."

For more information, see Green City Solutions.

Content and images courtesy of Green City Solutions.

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