There is an ongoing struggle going on between solar developers and farmers. Land that is best for solar installations are often well suited to growing crops or raising animals. Some experiments are being conducted to bridge the needs of both energy producers and agriculture, such as the one conducted by the Fraunhofer Institute For Solar Energy Systems in Germany. It mounts solar panels on racks high enough to allow normal agricultural activities beneath them. The Fraunhofer researchers say their system greatly increases the productivity of any given parcel of land.
Other researchers at UC – Riverside and UC – Davis looked at the problem from a different perspective. They examined non-traditional solar panel placement in California’s Central Valley, a place where food production, urban development, and conservation measures compete for available land. In a study published in the journal Environmental Science and Technology, Michael Allen, a professor emeritus of plant pathology and biology at UC Riverside says many existing solar farms are built in areas where they encroach on natural or agricultural lands already under threat from urban sprawl.
“When a piece of land is developed for a solar installation, it is very unlikely to be reverted into agricultural land, even when the lease to the solar company eventually runs out. That’s because flattening and compacting the land, as well as the long-term application of herbicides to keep the site clear of weeds, spoils the land for future farming,” Allen says. “For this reason, it is important that we explore alternative sites for new developments as the industry continues to grow.”
The researchers examined four unconventional siting options:
(1) developed areas within agricultural landscapes, such as rooftops, transportation corridors, and parking lots;
(2) land that is too salty for crops to grow, either because of naturally occurring salts or buildup from human activities;
(3) reclaimed areas that were previously contaminated with hazardous chemicals; and
(4) reservoirs and irrigation channels that can accommodate floating solar panels.
The results identified 8,400 square kilometers — equal to 183,000 football fields — the researchers believe would be suitable for large solar installations. That’s enough space to generate a staggering 17 348 terawatt-hours of photovoltaic and 2213 terawatt-hours of concentrating solar power per year without infringing on farmlands or protected conservation areas — more than enough to meet the entire state’s predicted energy needs for the year 2025.
“The study highlights the wealth of sites for solar energy generation that don’t conflict with farmland or protected areas,” said Rebecca R. Hernandez, assistant professor of earth system science and ecology at UC Davis. “Since farming is an incredibly energy-intensive industry, the land-sparing sites we identified could provide a win-win situation for both farmers who need more energy and the energy providers that wish to serve them.”