
Cynthia and Paul Stancioff
The spectral image of vast quantities of prime American farmland being suffocated by photovoltaic arrays has recently gained traction in the popular imagination.
People are led to fear that pursuit of solar energy will destroy our food security: In repurposing the landscape, will we be left with solar-powered kitchen appliances but no food to cook?
For anyone concerned about this alleged competition between solar energy and American farmland, there is abundant reassurance to be found in some simple facts and numbers, which we share here, inspired partly by a recent letter addressed by Congressman Jared Golden to the secretaries of the U.S. departments of Agriculture and Energy.
The concern Golden expressed to them was that we are on a trajectory toward covering half of America’s prime farmlands with solar arrays. He apparently inferred this from the American Farmland Trust’s observation that if current trends continue, 80% of the U.S.’s new solar projects might be sited on farmland.
What’s the actual relationship of solar energy acreage requirements and U.S. farmland acreage?
In its 2020 Solar Futures Study, the U.S. Department of Energy states that to meet climate goals for 2050, the U.S. will need 10 million acres of photovoltaics. The U.S. currently has around 880 million acres of farmland (with about 220 million just for corn, soybeans, and wheat). Ten million acres is closer to 1.2% of that farmland, not 50%. And that would be if all of the panels are sited on farmland (no rooftops, no parking lots, no use of lands unsuitable for other uses).
The study projected that “In 2050, ground-based solar technologies require a maximum land area equivalent to 0.5% of the contiguous U.S. surface area, which could be met in numerous ways including use of disturbed or contaminated lands unsuitable for other uses. The maximum solar land area required is equivalent to less than 10% of potentially suitable disturbed lands, avoiding conflicts with high-value lands in current use.”
In the last 20 years the amount of U.S. farmland has decreased by more than 65 million acres (U.S. farming: total land in farms 2023 | Statista). This is six times what we need for solar. It seems we should be more concerned about farmland that is taken out of food production for reasons other than solar.
An exemplary farmland/energy-use topic for consideration might be our ethanol subsidy policy. Right now we use 24 million acres to grow corn for ethanol (about a quarter of all our corn acreage, and 2.4 times what we need for all of our solar). This is mostly for use as a gasoline additive.
In energy terms, an acre of corn planted for ethanol produces enough net energy to move a typical internal combustion powered car about 2,500 miles per year. The same acre with solar panels could move a typical electric car around 1 to 1.5 million miles per year. That is over 400 times more.
These are relatively straightforward calculations based on readily available data that readers can verify for themselves.
By the way, other biomass sources of energy — e.g. wood pellets or chips — are no better than corn ethanol in terms of how much energy comes from an acre of land.
And while the American Farmland Trust does express concern about siting solar on valuable farmland, it is also quite supportive of smart use of land for solar, including agrivoltaics, or using solar panels in a symbiotic way with agriculture to actually increase yield and biodiversity while generating electricity (Smart Solar — American Farmland Trust).
Again, the beauty of employing actual numbers and quantities in the context of our unfolding energy transition is that they are in general quite affirming, and provide a foundation for optimism.
Paul Stancioff, Ph.D., is an emeritus professor of physics at the University of Maine at Farmington. He and Cynthia Stancioff, who holds a Master of Public Administration degree, live in Camden.
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