Methodology for the estimation of cultivable space in photovoltaic installations with dual-axis trackers for their reconversion to agrivoltaic plants

Agrivoltaics or dual use of land for agricultural production systems and photovoltaic energy is experiencing a significant boom since it favours the sustainability and efficiency of both systems, while helping to alleviate the conflict over land use and protecting rural economies. In this context, it is essential to study possible combinations between photovoltaic installations and agricultural operations that optimize the synergies between both production systems. Specifically, since solar irradiance is the common resource shared by both systems, it is necessary to find a balanced distribution of the solar energy to protect agriculture. This work simulates the behaviour of solar irradiance and its interaction with photovoltaic panels and the crop, as well as possible shading, in a photovoltaic plant to study its potential reconversion into an agrivoltaic installation. From this analysis, an innovative methodology is defined to determine the space between the collectors in which the levels of solar irradiance received would be sufficient for adequate crop development. Specifically, the method has been applied to simulate "El Molino" plant, a photovoltaic facility located in Córdoba, Spain with two-axis (azimuthal and elevational) solar trackers and backtracking. For this facility, pentagonal arable streets between the collectors have been identified. Specifically, along the N-S direction these pentagonal areas have a width of 10.5 m, a minimum height of 1.31 m in the lateral areas and a maximum height of 2.81 m in the central. Accordingly, different proposals for crop occupation have been proposed. Likewise, the curve of the percentage of maximum cultivable area as a function of the crop height has been represented, obtaining that for crops with a height of 1.4 m up to 74% of the land between collectors is arable, decreasing this space as the height of the crop increases. Thus, this work represents progress in the possible reconversion and agrivoltaic use of large existing photovoltaic plants, improving their sustainability and contributing to the necessary deployment of agrivoltaics and the fight against Climate Change.