Is it time for photovoltaic greenhouses?
Future agriculture systems are concerned by two main challenges for humankind: to produce enough to feed a growing world population, and to produce the share of renewable energies. Among these, biofuels and photovoltaics compete for arable land in food production. Photovoltaic systems can combine with extensive agriculture or livestock; in addition, they can share the solar photon flux with plants providing them with protection. Some years ago, we discussed photovoltaic greenhouses (PVG) and the potential synergies between protected agriculture and photovoltaic systems. We concluded that socio-economic and environmental efficiency could be higher in the combined photovoltaic greenhouse than in the solar or the greenhouse systems independently. We highlighted several R&D areas which would strongly impact short-term profitability of the PVG: firstly, to optimize greenhouse designs to incorporate PV systems; secondly, to develop innovative PV systems capable of intercepting a part of the solar spectrum, and of transmitting the useful wavelengths for crops and lastly, to select the crops and cropping systems adapted to the new constraints. The photovoltaic industry is very dynamic and innovative. In just a few years, many new photovoltaic technologies have evolved, better, more diverse, efficient and cheaper technologies arrive on the market every month. Currently, photovoltaic systems can be embedded in semi-rigid supports and can intercept a part of the solar spectrum. Moreover this intercepted spectrum can be chosen and can range between predefined maximum and minimum limits. Other photovoltaic systems have particles oriented in such a way as to intercept perpendicular beams within a solid angle and transmit the rest. They intercept, for instance, the midday beam in summer and transmit it in winter thus helping to passively control the greenhouse temperature and lengthening the cropping periods in regions with hot summers. The photovoltaic industry is rapidly offering innovations that will shake up the greenhouse agriculture. To conclude, the answer to the initial question will definitely depend on the capacity of agriculture and greenhouse industries to follow the pace of ongoing innovation in the dynamic photovoltaic industry.
Suay, R., Poncet, C. and Fatnassi, H. 2017. Is it time for photovoltaic greenhouses?. Acta Hort. (ISHS) 1170:915-920
innovation, PVG, greenhouse design, photo selective materials