The infant industry of agrivoltaics most often combines a large solar farm with pollinator-friendly vegetation rather than crop production, said USDA analysts. In the near term, the land might also be used for sheep pasturage or for high-value crops such as blueberries, but most farm equipment is too big to work around the panels.
“Because the industry is so new, the commercial viability of AV (agrivoltaic) systems with crop production is yet to be established,” said the Economic Research Service report. “The AV sites with crop production largely include those sites with a variety of specialty crops that can be harvested by hand.” Shade-tolerant crops were best suited for the mixture of agricultural and renewable energy production.
Agrivoltaics attracted interest with the rise in solar power generation in the past decade for its potential to create room for food and energy on the same land. “Whether AV systems can achieve these beneficial outcomes is unclear,” wrote the analysts. Agrivoltaics is such a new technology that the term has been applied to at least three approaches, including solar panels on greenhouse roofs.
There were 309 utility-scale agrivoltaic installations in 2022, and approximately 274 of them, mostly in the Midwest, were planted with pollinator-friendly vegetation, said the ERS report. Fifteen of them combined pollinator vegetation and sheep grazing.
“To date, AV systems with commodity crop (e.g., wheat, corn, soybeans) production have been infeasible, although research is ongoing,” said the USDA analysts. Berries, fruit, and wine grapes could be integrated into solar production, according to researchers, but economics did not favor large-scale crop production. The solar panels must be elevated and spaced further apart to accommodate farm machinery, which increases the cost of installing the system and decreases the generating power per acre. The shade created by the solar panels can affect yields for some crops.
Purdue University researchers say they have found a less expensive way to mix solar panels with major field crops such as corn, rice, soybeans, and wheat. The standard approach has been to build towers tall enough for farm equipment to move around beneath the panels, but the Purdue approach uses shorter towers. “When farm equipment needs to pass, the modules will rotate to form a near-vertical structure,” said Purdue professor Mitch Tuinstra last May.
The Energy Department has provided research money for agrivoltaic projects. The USDA included an agrivoltaic project in its climate-smart agriculture initiative.
Solar energy provided 3 percent of U.S. electrical generation in 2020, but its share was projected to increase to as much as 20 percent by 2050.