One example comes from Germany, where Fabian Karthaus, in order to continue his father’s farming business, decided to build two photovoltaic plants with a capacity of 750 kWp.
The heat and drought have caused a significant drop in yield in recent years, so he came up with the idea of growing berries under a solar roof, with translucent modules (usually, this type of plant is grown outdoors or in aluminium tunnels).
In addition to the self-consumption of the clean energy generated by the PV, which is used to run the refrigeration and freeze-drying systems, the shade created by the modules increases the yield. Extremely hot summers are a growing problem, even in Germany.
Roofs made of solar modules also reduce evaporation, leading to water savings. “Evaporation is about a quarter of what it is in open fields,” Fabian explains.
In Germany, this cultivation method works well for berries, apples, cherries, potatoes and products such as tomatoes and cucumbers. Each region of the world and each type of culture will have to be approached in a customised way, and to achieve maximum benefits, depending on the location, the optimum light conditions for the plants and the local demand for electricity must be estimated.
Agri-voltaics is the use of agricultural areas to simultaneously produce food and generate photovoltaic electricity.
There are already several agri-voltaic plants in Europe, Mali, Gambia and Chile.
The world’s largest plant, with a capacity of around 1,000MWp and covering 20 square kilometres, is located on the edge of the Gobi Desert in China. The cultivation of goji berries under the module roofs is intended to make a parched land fertile again.
In Europe, it is France that is the pioneer, especially in viticulture. PV modules can protect the vines, provide some shade and improve yields, as many vines receive too much sun and heat due to climate change.