Agrivoltaics: what it is, how it works, and which crops and livestock can be integrated

How does agrivoltaics work?

The principle of agrivoltaics involves designing a photovoltaic installation whilst taking into account both electricity generation requirements and the needs of agricultural activity. Solar panels intercept part of the sunlight to generate electricity, whilst the rest reaches the crops or areas used for livestock. The aim is not simply to install panels on agricultural land, but to achieve a dual and functional use of the land. The design must take into account variables such as:

• Height of the modules: this must allow for crop growth, the movement of animals or the passage of the necessary agricultural machinery.
• Row spacing: this determines the amount and distribution of radiation reaching the crops.
• Orientation and tilt: these affect both photovoltaic output and the distribution of light and shade across the site.
• Monitoring system: certain projects use solar trackers capable of adjusting the position of the modules and dynamically managing the balance between electricity generation and agricultural needs.
• Type of crop: each species has different requirements in terms of light, temperature and water.
• Climate and water availability: these determine whether the partial shading provided by the modules is an advantage or a limitation.

The panels also alter the microclimate beneath and around the installation. Shade can reduce direct radiation on the crop, alter soil temperature, partially reduce evaporation and provide protection against certain heatwaves. However, these effects are not always positive. Excessive shade can hinder the growth of certain species. For this reason, agrivoltaics requires the energy and agricultural components to be designed in tandem, rather than simply optimising photovoltaic output.

The IEA PVPS It emphasises, in particular, that the performance of an agrivoltaic system must be assessed in an integrated manner, taking into account photovoltaic generation, agricultural production, the microclimate and the specific characteristics of each site.

Solar panels, agriculture or livestock: which crops or animals are suitable for agrivoltaics?

A crop’s suitability for agrivoltaics depends on its tolerance to shade, its radiation requirements, the climate, the geometry of the installation and agricultural management practices. Consequently, there is no universal list of crops that will always yield better results when grown beneath solar panels. Among the most common or widely studied applications are:

• Vineyards: viticulture is one of the most promising applications of agrivoltaics in Europe. The structures can be designed to span the rows of vines and provide partial protection against extreme temperatures or certain weather conditions.
• Fruit trees: apple trees and other fruit trees can be combined with elevated photovoltaic structures. Depending on the design, the panels may also provide some protection against excessive radiation, hail or adverse weather conditions.
• Red berries: certain crops, such as raspberries, blackberries and blueberries, may thrive in partially shaded conditions provided the system is correctly sized.
• Leafy vegetables: lettuces, spinach and other crops with lower requirements for direct sunlight can be suited to certain agrivoltaic set-ups.
• Tomatoes and other vegetables: there are experimental and commercial projects investigating the balance between shading, temperature, water requirements and yield.
• Extensive crops: cereals, potatoes and other agricultural crops can also be integrated, although they require designs that ensure access for machinery and an appropriate distribution of radiation.
• Pastures and forage: the areas beneath or between the panels can be used to maintain vegetation for animal feed.

The FAO describes agrivoltaics as the combination of agricultural production and electricity generation on the same land, and highlights its potential to optimise land use, increase resilience to climate change and provide new sources of income for farms.

Agrivoltaics can also be integrated with livestock farms. In such cases, the land retains its productive function through grazing or activities related to animal husbandry whilst generating photovoltaic electricity. The most common example is sheep grazing on solar farms. Their size and behaviour make it easy for them to move between photovoltaic structures, whilst at the same time, grazing helps to control the growth of vegetation. Possible applications include:

• Sheep: these are probably the most common livestock species found on photovoltaic sites where grazing takes place. As well as making use of the land, they can reduce the need for certain forms of mechanical weed control.
• Cattle: can be accommodated in systems specifically designed with structures that are sufficiently high, sturdy and protected. Their larger size necessitates higher structural and safety requirements.
• Poultry: hens and other birds can use certain areas around or underneath the modules, making partial use of the shade provided by the structures.
• Beekeeping: some plants combine photovoltaic generation with vegetation that is favourable to pollinators and the siting of beehives. Although this does not constitute grazing, it represents another form of agricultural activity that is compatible with certain solar projects.

The IEA PVPS lists sheep grazing, beekeeping, vineyards and fruit orchards among the existing applications of agrivoltaics, reflecting the diversity of possible configurations. Not all species are equally suitable. When integrating livestock, consideration must be given to the height of the panels, cabling, electrical safeguards, access routes, water availability, animal behaviour and the risk of damage to the infrastructure.