Agrovoltaic farms could provide the perfect balance between agriculture and renewable energy production

In the not-too-distant future, agri-voltaic complexes could replace existing photovoltaic farms, combining the benefits of renewable energy from the sun with the advantages of sustainable agriculture.

Particularly in regions of Europe with soil suitable for agriculture, the siting of PV installations always comes at the trade-off of taking large areas of fertile land out of agricultural use, with the gains for entrepreneurs investing in such projects coming at the expense of permanently reducing grain production in the country concerned.

Although, on the one hand, they lead to lower yields by shading agricultural crops, the shade provided by photovoltaic panels can provide crucial help in conserving soil moisture during dry periods and protecting crops sensitive to heatwaves. Paradoxically, it increases production for certain crops, such as tomatoes or grapes.

Apparently, the secret to record earnings from Agrovoltaics is the development of a certain type of semi-transparent photovoltaic panel, capable of selectively blocking incoming sunlight. Ideally, the photovoltaic system should stop wavelengths useful for generating electricity, allowing the light spectrum useful for plant growth to pass through.

Borrowing some ideas from artificial plant growth installations, scientists are experimenting with light filters for now. The general conclusion is that blue light and the ultraviolet spectrum are the least important for plant growth, but still transmit enough energy to be harnessed with photovoltaic panels.

Although, with some loss of productivity, quite a few agricultural crops can also grow under filtered red light from the sun, the main obstacle remains the development of photovoltaic cells with these characteristics that can be manufactured at competitive prices.

Inevitably, there will be losses for both types of ‘yields’, but with the right crop choices, researchers at Michigan Technological University believe the benefits far outweigh the drawbacks. For example, crop irrigation requirements can be reduced by up to 29%, while yields of some heat-sensitive crops (e.g. tomatoes) can be increased above baseline levels simply by protecting fruit that would otherwise have rotted in the sun’s rays before harvest.