Gardens on façades and roofs combined with transparent photovoltaic panels could increase energy efficiency while also providing improved insulation.
The Vienna University of Technology conducted a research project studying the effects of growing plants on façades and roofs in a research project. The researchers discovered that greening these outer surfaces cools the photovoltaic panels which in turn increases their output. Flat metal roofs can reach up to 80 degrees Celsius in the summer; greening them helps maintain their ambient temperature.
The same principle holds true for façades. Transparent photovoltaic panels can simply be hung in front of the plants, allowing 80 per cent of sunlight to still reach the plants.
Other positive effects of greening have to do with regulating temperature and humidity, capturing particulate matter, and reducing noise. It would also help counteract that the urban heat island effect and prevent flooding by storing rain water.
Photo credit: TU Wien