Read the German version

City Tree: Smart moss wall purifies city air

All over the world, cities are increasingly struggling to combat rising levels of air pollution. Nitrous gases, particulate matter and CO₂ are damaging not only to the environment, but also to human health. According to the World Health Organisation (WHO), 90 percent of all city-centre residents breathe in polluted air on a daily basis. But Berlin-based start-up Green City Solutions has devised an environmentally friendly way to tackle this problem: The City Tree filters large quantities of hazardous substances out of the air to improve quality of life in the urban sprawl.

Breathe deeply with the City Tree: Moss wall purifies city air

The City Tree is equipped with a patented bio-tech filter that uses moss to clean the air.

The freestanding moss wall creates the perfect conditions for plants to thrive in urban spaces. The system – which acts as a kind of artificial tree – uses different types of moss to bind CO₂ and other substances that pose a danger to the environment. The moss walls also produce oxygen, store moisture and boast a large evaporation surface, which helps to cool the surrounding area.

The vertical green space waters itself, taking moisture from rain or drawing from its own fully automatic irrigation system. The filter fans are powered by electricity generated by the system’s own solar panels or from the local grid.

How the City Tree works. Source: glasgowcitycouncil / YouTube

Moss as an air purifier: Equivalent to 275 trees thanks to IoT technology

To boost the efficiency of the bio-filter, the developers of the innovative new system kitted out their moss wall with all of the latest technology, with full Internet of Things (IoT) compatibility. Integrated sensors generate data on the local climate, air quality and system performance in real-time. All of this data is analysed and displayed via the system’s own cloud platform “Aircare”. Through this system, owners of the City Tree – primarily local authorities and companies – can view detailed information on environmental parameters such as particulate emissions generated by traffic, and adjust the filter performance accordingly. With all of this technology on board, the City Tree – which takes up just 3.5 square metres of space – cleans the air as efficiently as 275 trees.

City Trees already planted around the world

The artificial trees have already taken root in cities across Germany, including Dresden, Jena, Leipzig, Darmstadt and Berlin. Other world cities, such as Oslo, Hong Kong and London, have also used the moss walls and their integrated benches to create calming spaces for rest and reflection in urban environments.

In spite of the positive reception to date, the smart bio-filter system is still at the prototype stage; the product is subject to ongoing development and optimisation work. There are numerous developments in the pipeline for the moss walls in the future, including a modular system to allow for more flexible use.

smart moss wall purifies the air

Artificial trees for a more sustainable natural urban environment

Tests undertaken by external bodies have already confirmed that the artificial trees filter CO₂ and reduce the levels of damaging substances in the air. Green City Solutions also works closely with a number of research and technology partners, as well as the TÜV Nord Group, to perform comprehensive site analyses, tests and simulations. The international team is supported by the European Union, which set up a subsidy programme for the installation of moss walls.

Recognition for Green City Solutions

Since it was founded in 2014, Green City Solutions – which was taken over by Thies Network GmbH earlier this year – has been recognised for its success on a number of occasions.

In the company’s first two years of operation alone, it clocked up more than 45 awards and nominations in national and international competitions.

Innovative ideas and solutions for sustainable urban development are more in-demand than ever before. Although the City Tree is by no means a sole solution to the challenges that growing cities face, it does have an important role to play as a pioneering product that reduces environmental impact and improves quality of life in urban spaces.

Do you think the City Tree would work well in your home city? Tell us what you think of the artificial tree concept in the comments.

Smart Living Sustainability

Start a discussion about this article

This will also interest you