Progress and Challenges of Crop Production and Electricity Generation in Agrivoltaic Systems Using Semi-transparent Photovoltaic Technology
The world population and consequently the global need for food continue to grow. At the same time, areas will be used to generate clean electricity to cope with climate change and global warming. The combination of crop production and solar photovoltaics in the form of ""agrivoltaic technology"" offers advantages for both sides that provide an adequate, resource-efficient solution to the persistent problem of competition for arable lands. The implementation of agrivoltaic systems has been exponentially increased in recent years and reached the global installed capacity of 2.8 GW in 2020 from the initial capacity of 5 MW in 2012. The agrivoltaic systems installed worldwide mostly employ conventional opaque photovoltaic (PV) modules, causing a change in the microclimate under the panels that become critical when shading ratios are high. Semi-transparent PV (STPV) modules have been recently employed to mitigate this issue which is profoundly studied in this research by considering the use of semi-transparent technologies based on crystalline silicon (c-Si), thin-film photovoltaics, organic PVs (OPVs), dye-sensitized solar cells (DSSCs), concentrating PVs (CPVs), and luminescent solar concentrators (LSCs) in open (arable farming lands) and closed (cultivation greenhouses) agrivoltaic systems. The results indicated that c-Si STPV modules have the highest share of employment in agrivoltaic systems due to their extreme benefits of low costs, high stability, and high efficiency in comparison with other technologies, while in contrast, the use of thin-film STPV modules have been rarely reported in the literature. Additionally, STPV modules using OPVs and DSSCs offer the capability to achieve wavelength-selective transparency, causing the photosynthetic active radiation to pass through while the remained spectrum is utilized to generate electricity. Other potential solutions come from CPVs and LSCs, in which, diffuse light is available for the growth of cultivated plants, while direct concentrated sunlight can generate electricity. Although STPV modules are proven as a feasible solution for use in agrivoltaic systems, still more developments are required in terms of the modules' efficiency enhancement and costs reduction, while more detailed research is required to observe the response of cultivated plants to make this technology a viable sustainable solution in the future.