Research conducted by the University of Sheffield has investigated the scope to which solar panels can be viably incorporated into agricultural land in the UK.
They found the potential for agrivoltaics – the use of land for both agriculture and solar energy production – is high enough to meet the UK’s electricity needs more than four times over.
One of the most common reasons that planning permission for solar parks is refused is loss of agricultural land, yet land that is ideal for agriculture is often also perfect for solar PV deployment.
Using 2021 figures, ground-mounted solar farms occupy 0.07 % (161 km²) of land in Great Britain, although two-thirds are in the south of England. Nearly 80% of these are situated on agricultural land which has been graded between ‘excellent’ and ‘good’ for agriculture.
There is also a grading system for the suitability of land for solar farms, so the researchers set out to find how much cross-over there was between the best land for solar and the best land for agriculture.
It turns out that 23,593 km² (9.2 % of Great Britain) is highly suitability for solar while also being high-grade agricultural land.
In agrivoltaics, PV panels are integrated into existing farming activities, either among or above crops and livestock.
Professor Sue Hartley, Vice-President for Research and Innovation at the University of Sheffield who co-authored the study, said: ‘The Government and solar developers have ambitious plans for the expansion of solar farms but these risk the loss of agricultural land needed for food production at a time when global food security is threatened by geopolitical uncertainty and climate change.
‘Agrivoltaic technology is a potential way out of this dilemma. It allows us to use the same area of land for both food and clean energy production, addressing some of the criticism levelled at solar farms. This technology is in regular use in many areas of the world, including areas like Scandinavia with less sunlight than the UK, but has not yet been adopted here.
‘Our research identifies the areas in the UK where this technology can be most effectively deployed, both to mitigate land use conflicts and deliver the UK’s energy needs.’
It was seen that the East of England has the most of this ‘best of both worlds’ land, covering 6,693 km² with 98.0 % of grade 1 agricultural land having high potential for conflict with PV. The West Midlands, East Midlands, and South West also have over 8,194 km², combined, of potential high-grade agricultural land use conflict areas.
Studies undertaken overseas have identified that agrivoltaic schemes can be beneficial for crops. When solar panels are situated above crops, their shade can help prevent water loss. During hot conditions in Germany, potato yields under the shade of solar panels increased by 11%.
Wheat, a major crop in the UK, also benefits from the prevention of water loss but, conversely, is negatively affected by the absence of direct sunlight. In these cases vertically positioned solar panels might be considered. The research observes however, that even with raised panels casting shade, the overall land productivity – that is, including revenue from energy generation – is most likely to increase.
Co-author Dr Richard Randle-Boggis, who conducted agrivoltaics research at the University of Sheffield and is now a research scientist at SINTEF, said: ‘Research on agrivoltaics is extensive in mainland Europe, but very little has been done in the UK.
‘Our next step should be field experiments to test the performance of the systems, investigate different designs with different crops and better understand the perspectives of local communities and other stakeholders.
‘The loss of farmland is typically a major reason communities oppose solar park development in their local areas. Our research takes a leading step in demonstrating where solar parks could be developed alongside agricultural activities so that farmland is not lost.’
The full research can be read here.