The eco-sustainable reality that governments aspire to build requires the rapid development of renewables. In Italy, photovoltaics play a leading role in this endeavour, both because solar radiation is abundant in our country and because silicon panels are one of the most reliable and technically mature technologies for exploiting alternative energy. However, their massive diffusion is prevented by the scarcity of available surfaces: there are areas blocked by landscape restrictions, urbanised areas and areas designated for agriculture. The idea is therefore to install the panels on existing buildings, but even here there are many obstacles: often buildings with poor exposure to the sun or buildings of historical, architectural or artistic value. This is why a new way of conceiving photovoltaic systems is spreading: agrivoltaics.
Agrivoltage consists of integrating solar panels at a certain height (around 4-5 metres) into agricultural land so that farming can be carried out underneath. It is a new concept that establishes a synergy between land for agricultural use and land for energy production, with the aim of reducing consumption and improving the performance of farms.
This approach was first presented in 1981, by German Adolf Goetzberger, in his article with the catchy title "Potatoes under panels". Since then, numerous experiments have been carried out, many of them with positive results. In 2010, Frenchman Christian Dupraz demonstrated that not only was the yield of a plot completely covered by solar panels similar to that of one only partially covered, but that in the former there was less evaporation of water from the ground. In fact, agrivoltage does not compromise soil yields, but in some cases can help improve them. In 2016, a study by the Fraunhofer Institute showed that by installing panels at a certain height above the ground, both agricultural and solar yields were 80% higher than if the soil had no solar and the soil had only been used for photovoltaics . Today, however, the use of the word agrivoltaic indicates not only the simultaneous presence of the two activities - agriculture and energy transformation - on the same land, but also the provision of agronomic benefits to crops thanks to the presence of the panels. What are these advantages?
During the hottest periods of the year, the panels protect the crops, keeping the soil at a lower temperature and allowing it to retain more water. This could be particularly important in certain parts of our country, for example in the south, where water resources are scarce and the heat is more intense. During the night, on the other hand, the panels prevent the soil from reaching excessively low temperatures, reducing the stress on the plants caused by temperature fluctuations. The roof can also provide shelter from extreme weather events. Agro-voltaics could therefore play a key role in developing resilience in agriculture, which is indispensable for dealing with the climate changes that will hit us in the coming years, with a general rise in temperature and an increase in the frequency of violent phenomena in many areas of our planet.
Of course, the response of the soil changes from time to time, depending on the characteristics of the different crops; some crops have shown to be more suitable than others for the installation of similar systems: tea, berries, rice, vines and some fruit plants perform well under panels. Animal husbandry is also compatible with agri-voltaics.
However, agri-voltaic systems are available in a variety of technologies and configurations, allowing the best solution to be found each time. Certain design solutions can affect rainwater distribution or shading. Most plants only need part of the sun's radiation to carry out photosynthesis. The panel is therefore designed in such a way as to let through only the radiation needed by the crops, and retain the rest to convert it into electricity.
According to some studies, the crops themselves could contribute to energy production: solar radiation hitting their surface is reflected and can be directed towards overlying panels, in this case double-sided, i.e. panels with an action surface on both the front and the back.
According to the National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA- italian acronym), if 0.3% of Italian agricultural land were covered by agri-voltaics, 50% of the targets of the National Integrated Energy and Climate Plan (PNIEC- italian acronym) could be reached. .
However, there is still a lack of clear guidelines for plant design, setting requirements for height, for example, or distance between panels. Shared with photovoltaics is the problem of long and complicated authorisation procedures. But compared to classical photovoltaics, the final cost of the produced energy is slightly higher (9 euro cents per kWh instead of 8 cents/kWh), due to higher investment costs .
 Lanciamo l’agro-fotovoltaico in Italia, qualEnergia.it, 28/01/2019, https://www.qualenergia.it/articoli/lanciamo-lagro-fotovoltaico-in-italia/
 Agrivoltaico sostenibile, https://www.agrivoltaicosostenibile.com/
 Agrivoltaico, tante potenzialità ma troppi colli di bottiglia per autorizzazioni e incentivi, qualenergia.it, 14/05/2021, https://www.qualenergia.it/articoli/agrivoltaico-tante-potenzialita-troppi-colli-bottiglia-autorizzazioni-incentivi/