Apart from providing improved insulation to buildings, lowering power consumption (by as much as 6%), providing habitat for some animals, filtering out air pollutants, and lowering ambient temperature, green roofs may also improve solar cells’ performance.
Two separate studies have been investigating the synergistic effect of green roofs to solar panels and have shown to improve the latter’s efficiency by 3% to 16% more.
Two reasons are seen as to why green roofs affect positively a solar cell’s performance. First is the cooling effect of green roofs. Solar cells were found to perform better in cooler conditions, making the green roofs a suitable venue for solar cell installation. Next is the air filtration effect of green roofs. Dust- and pollutant-free environment also enhances solar energy absorption of solar cells.
However, the two studies have resulted to two significantly different efficiency improvement values. The study performed by Bronx Design and Construction Academy resulted to an efficiency increase of 3%, while the study conducted by American Solar Energy Society gave an efficiency improvement of 16%.
This large difference is due to the dependence of the synergistic effect on factors such as the types of plants, building, and solar panel used in the study. Still, the important thing is that the green roofs may improve solar cells’ efficiency.