The Photovoltaic Greenhouse as Energy Hub for a More Sustainable Agriculture

This work introduces the concept of the greenhouse as an energy hub in agriculture thanks to the addition of roof-mounted photovoltaic systems integrated into the structure of the greenhouse. The results of a project comprising the design, construction, and evaluation of the energy production of two photovoltaic greenhouses over two years are presented. One greenhouse is equipped with conventional PV panels (PVG), and the other with semi-transparent panels (ST-PVG). For the PVG, the upper half of the roof is covered with 22 conventional PV panels, resulting in overall roof transparency of 50%. For the ST-PVG, the entire roof of the greenhouse was covered with 48 semi-transparent PV panels with nominal transparency of 20%. The analysis methodology consisted of the following steps: obtain data stored on the web platforms of PV systems providers, compare the actual annual production of each greenhouse with the theoretical annual production estimated with the solar explorer web tool, quantify the difference between the actual data and the theoretical estimate, quantify the loss of energy production of the existing system. It was empirically verified that both installed PVGs would tend to produce less energy than theoretically expected every year, with an average production loss of 7.85%. This result represents a realistic Figure for estimating the production of a PVG operating under actual conditions and without considering the cleaning of PV panels.