Christopher Bonasia
The Advocate

New studies continue to suggest that agrivoltaics – the dual use of land for solar energy production and agriculture – can work for both farmers and clean energy production, but the pairing is more nuanced than a straightforward win-win.

Trials on agrivoltaic sites in the northeast United States show that solar panels help produce better quality forage, while grazing tends to build soil health. The findings are presented in a recent study by the American Farmland Trust, “Sheep Grazing Impacts on Soil Health and Pasture Quality at Commercial Solar Sites in Northeastern USA.”

Measurements taken on 28 grazed solar sites over two years were compared with fenced-off control sections and to three ungrazed solar panel locations.

Improved forage quality

Forage quality improved under solar panels year-over-year on all sites in all seasons, with forage analyses showing increased crude protein and lower non-digestible fibre and neutral-detergent fibre.

The study also suggests that grazing under the panels tended to improve soil health, and points to increased organic matter and better pH levels. However, the analysis of effects on soil health fell just shy of being statistically significant, with a p-value of 0.06. This means that, if grazing had no effect on soil health, the researchers would still expect to see the same results 6 per cent of the time. A p-value of 0.05 or lower is considered the threshold for statistical significance.

The mutual benefits shown in the study support efforts to pair solar power generation and food production to reduce competition between the two land uses.

Significant power potential

In 2023, another study — The Agrivoltaic Potential of Canada, released by Western University —stated that agrivoltaics offered significant opportunity for Canada, claiming that 25 to more than 33 per cent of the country’s electricity energy needs can be met if agrivoltaics were installed on only 1 per cent of current agricultural lands.

In Quebec, this mean the province would be able to completely shift away from burning fossil fuels for electricity generation by installing solar panels in only 0.01 per cent of farmland, because so much of the province’s electrical needs are already met by hydropower.

Solar grazing with sheep has drawn a lot of attention because it does seem to be a good pairing, but balancing land uses can get trickier when other kinds of food production are displaced to build solar panels.

Grazing among panels

Notably, all of the solar sites in the American Farmland Trust’s study had been constructed for the purpose of energy generation. The sites had mostly been croplands for hay or corn before hosting solar panels, with a lesser portion of sites having been open fallow land or woodland. This sample selection was by design, so that the researchers could start from a blank slate at all locations. Local graziers had been hired later to operate the land as agrivoltaics sites.

Some crop farms have been able to incorporate solar panels, though this practice is used to a lesser degree than grazing. But sheep are not always the best agricultural land use for all land types, and solar developers may still push solar grazing as a way to access agricultural land.

Last summer, the Alberta Utilities Commission denied a permit for the Westlock Solar project that was sited on Class 2 land. The commission said the developer’s plan to hire an operator to graze sheep on the site would downgrade the value of the land’s current crop production.

Westlock had chosen not to plan for crop production so that it could space panels closer together to have a smaller land footprint, and because specialized equipment to grow crops under panels would be a costly deterrent for farmers.

The tension between land uses was highlighted in yet another recent study of agrivoltaics sites in California, Impacts of agrisolar co-location on the food–energy–water nexus and economic security. The researchers found that agrivoltaics did displace food production, but farmers with solar panels on their land reported greater economic security as expenses for inputs like fertilizer, water and farming supplies were lower, and income from selling made up for lost crop production.