University of Wisconsin on Solar vs Ethanol for Land Use: Spoiler, Solar is Way Better
February 1, 2023
But you knew that.
That whole thing with “oh, please don’t use our farmland for solar” is, as I’ve been saying, bullshit.
New study out of U Wisconsin.
Corn Ethanol vs. Solar Land Use Comparison – University of Wisconsin:
Wisconsin already uses over 1,000,000 acres of agricultural land for energy production in the form of corn used to produce ethanol.
Ethanol is a much less efficient form of energy production compared to solar photovoltaics (PV).
Using Energy Return on Investment (EROI) as a metric, solar PV is around 8 EROI while corn- derived ethanol is approximately 1.2 EROI. Using this metric, 88% of the energy generated by solar PV goes to society, while 12% is offset by production requirements.
In contrast, 20% of the energy generated by corn ethanol goes to society, while 80% is offset by production requirements.
Assuming average EROI, net energy production per acre is 100-125x greater for solar PV than for corn-based ethanol
Looking at land-use efficiency, corn-derived ethanol used to power internal combustion engines requires about 85x (range: 63-197x) as much land to power the same number of transportation miles as solar PV powering electric vehicles.
Even if the ethanol is converted to electricity to power more efficient electric vehicles, corn ethanol still requires 32x the amount of land to power the same number of vehicle miles.
Corn Ethanol vs. Solar
Wisconsin’s one million acres of corn for ethanol can power 10 billion vehicle miles travelled annually with internal combustion engines or 23 billion electric vehicle miles annually. If replaced with solar PV, those 1 million acres could generate enough electricity to power 804 billion electric vehicle miles annually.
This translates to 1 million acres of corn ethanol powering annual travel of 700,000 internal combustion engine passenger cars or 2 million electric vehicles. The same area of solar PV could power the annual travel of 60 million electric vehicles.
These numbers are even more spectacular than the comparison given me by Josh Pierce PhD at Michigan Tech 3 years ago.