Agrivoltaics (AV) is the dual use of land for agriculture and solar generation to maximise land use. This is becoming an ever more important issue, particularly in the UK, as solar farm deployment continues. Dual use solar farms are currently achieved through the co-location of livestock, primarily sheep grazing, where they can reduce solar farm maintenance costs by managing foliage. Far less common is the co-location of large-scale photovoltaics (PV) with crops. There is significant ongoing research looking into dual use of land for crop farming with solar generation.
In agrivoltaic farming, the PV panels are typically elevated above the crops using frames to allow farming operations to continue beneath. Other configurations include rows of PV panels spaced to allow farm machinery to continue normal farming operations between them. These rows of PV panels may be the traditional tilted frames common to existing solar farms, or the more novel vertical PV panels that have a much smaller footprint. There is not yet a ‘standard’ configuration, with more variations in development, and the choice will be largely determined by the crops in question.
Elevated AV is well suited to shade tolerant crops like grapes, tomatoes lettuce, and so on, although this is still being studied. It has been found that cereals and grains have far higher yield losses under elevated AV than these shade tolerant crops because they need direct sunlight. In these cases, a vertical AV configuration may be preferable.
Research conducted in France indicates agrivoltaics can increase global land productivity by up to 73 per cent. Another agrivoltaic project, conducted by the Fraunhofer ISE, found land use productivity increased by over 60 per cent. The study had elevated solar panels installed above the crops, covering 3,300 sq. m of the farm.
What are the benefits?
- AV addresses land-use conflicts by reducing competition for land and increasing land productivity
- Reduced water use from added protection against evaporation from PV shading
- Increased solar yield per panel due to the plants lowering ambient temperature by evaporating water. This provides a small temperature regulation thus panels are cooled down. (Efficiency gains estimated to be 1 to 3 percent)
- Increases production for certain crops
- Potential revenue diversification opportunity for landowners/farmers
- Provides protection for crops in extreme weather such as heavy rainfall or extreme heat waves
Agrivoltaic vs ground-mounted PV
AV currently has higher associated installation costs as well as higher capital expenditure (CAPEX) compared with traditional ground-mounted PV systems.
Though AV currently has a higher upfront cost, the PV modules have a slightly increased solar efficiency and require less frequent maintenance due to the crops providing a greater natural cooling for the solar PV.
Pilot projects
Numerous agrivoltaic pilot projects have been launched successfully in countries such as Japan, France, Italy and even Kenya. These projects are in their experimental phase and an optimal model for integrated farming and solar generation that can be duplicated and reproduced is yet to be identified. It is also key to note location, climate and weather can significantly affect the results.
With growing concerns over loss of farmland as the rollout of solar continues, AV provides joined up technology that supports energy generation and agriculture. The high associated CAPEX is however a significant barrier in wider deployment.