Researchers at the University of Lisboa and the Military Academy in Portugal have conducted a study on the viability of agrivoltaics system to address the need for both energy and food security. The study found that spaced rows of photovoltaic (PV) modules combined with shadow-friendly crops had the most promising return and a payback period of less than five years.
Portugal's climate characteristics make it a suitable location for solar production and approximately 12% of the country's national territory is designated as National Agriculture Reserve (RAN) for agriculture purposes. Agrivoltaics system, the integration of agriculture and solar production, also called solar farming, could be an innovative solution to make use of the designated land while also generating renewable energy to address energy security concerns.
The group found that agrivoltaic systems can achieve a payback time of five years or less and generate more value than only PV systems or only agricultural production on the land. Additionally, in studying two types of layouts – one with elevated panels and one using spaced rows of panels – the researchers noted that the spaced solution has a slightly higher potential than the elevated one.
The team included a regular PV implementation for comparison and studied scenarios where all the energy produced by the panels was directly sold to the market using a calculated value. The analysis assumed that the farmer has a PPA and sells the energy at €0.043 ($0.046.34)/kWh. Monocrystalline silicon solar cells were chosen for the PV systems. To determine the payback period, various parameters were selected using PVsyst software, including initial investment and O&M costs and energy sales prices.
For the spaced PV project layout, a pitch distance of 20 m was used, creating a minimum of 15 m of space between the two rows of eight modules each, for a total of 16 modules. The modules had a 55% to -55% tilt angle, and trackers were used to follow the sun's movement and optimize the power output. In the elevated PV array layout, all 16 modules were installed in a single-row series to reduce shadowing on the crops beneath them. Again, a 55% to -55% tilt angle was chosen, using trackers. However, in the Valverdinho installation, the terrain created too much shadowing, so the tilt angle was adjusted to 45% and -45%.
The results of the research indicated that the proposed projects had a lower levelized cost of energy (LCOE) than the energy price in the Iberian market, with payback periods of around 4-5 years.
Agrivoltaics combine the principles of sustainable agriculture and renewable energy production. By shading crops, PV modules can reduce the amount of water evaporation and maintain cooler temperatures, leading to increased crop yields. Meanwhile, solar panels generate renewable energy that can be sold or used by farmers themselves, reducing their reliance on fossil fuels.
This study highlights the potential for agrivoltaics to offer a win-win solution by addressing both food and energy security issues, while also promoting sustainable agriculture practices. As the world's population continues to grow, innovation and creative solutions such as agrivoltaics will be key in addressing the challenges we face in the years to come.
