Green Energy for Housing Association

Commissioned by Jutphaas Wonen, Wallaard Vegetatiedaken installed the Solar Sedum Roof with a total surface of 2,500 m². The roof is fitted with no fewer than 378 solar panels. The renewable energy generated is not only beneficial for the environment, but also for the tenants. As participants in the project, tenants receive a 15-year discount on their energy tax thanks to the clean energy produced. In 2021, the annual yield was no less than 144,000 kWh, contributing to a reduction of 66,000 kg of CO₂ emissions.

Fast and efficient realization of sustainable projects

In several other projects by housing assocation Jutphaas Wonen, where green roofs combined with solar panels have also been installed, the housing corporation chose to finance the panels itself. “This way, we don’t need tenants’ approval, which results in a quick and efficient approach and realization of sustainable projects,” says Frans Bouwman, Project Manager Real Estate at Jutphaas Wonen.

Increased solar panel efficiency thanks to cooling green roof

So what makes the combination of a green roof with solar panels so sustainable? The reason lies in the cooling effect of the green roof. Solar panels achieve their highest efficiency at lower air temperatures. On hot summer days, however, rooftop temperatures can rise to 70 to 80 degrees. The vegetation of the Sedum roof keeps the ambient temperature lower, allowing solar panels to produce more power. With a Solar Sedum Roof, not only is renewable energy generated, but the efficiency of the solar panels also increases by 6 to 10 percent, thanks to the cooling effect of the green roof.

Boosting biodiversity

In addition to generating renewable energy, the Solar Sedum Roof makes an important contribution to local biodiversity. Sedum plants improve the habitat for insects, butterflies, and birds—especially in the paved environment of the city. The green roof serves as a stepping stone between gardens and parks in the built-up area. Furthermore, the Solar Sedum Roof positively contributes to air quality, climate, water management, and the living environment of city residents. This is also reflected in the enthusiastic responses from Jutphaas Wonen tenants, who overlook the lower-lying Solar Sedum Roofs.

“Sometimes we receive photos from residents showing how happy they are with their view.”