Solar Much More Efficient Use of Land vs Ethanol

January 22, 2022

Combining remarks from solar guru Josh Pearce PhD, with a nice succinct explanation I just came across analyzing land use for solar vs ethanol.
Ethanol is going away in any imaginable future – so if farmers need help to stay in business, making options like solar available to them as a drought-proof source of income just makes sense.


At $416 billion, American farm debt is at an all-time high. Since 2013, over half of all farmers have lost money each year and farm loan delinquencies are on the rise. From 2011 to 2018, the US lost more than 100,000 farms; 12,000 of which were lost between 2017 and 2018 alone. 

Many agricultural markets in the US are being artificially propped up by government subsidies and federal laws. In particular, the market for corn, the largest agricultural crop in the United States, is backed by a long history of subsidies and federal laws, including laws that require nearly all US gasoline to contain 10% ethanol, nearly all of which comes from corn.

Every year, US farmers plant around 140,000 square miles of corn, 30% of which is used to produce ethanol. Between 1978 and 2018, the ethanol industry received a variety of subsidies totaling $86 billion dollars, more than both the solar and wind industry combined. Despite all this government support, ethanol is often a money losing proposition for farmers. It is also one of the least efficient ways to generate energy. So, what if American corn farmers replaced their fields with solar farms?

If you compare the energy utility of an acre of solar panels to an acre of corn, the acre of solar wins by a landslide. 

Each year, one acre of corn produces 551 gallons of ethanol, which is the equivalent of 386 gallons of gas. Using the average miles per gallon of a US automobile, this equates to 9,691 miles driven per acre of corn per year.

In Iowa, an acre of solar panels produces 198,870 kilowatt hours each year. A typical EV drives approximately 3.6 miles per kilowatt hour. So, each year, an acre of solar panels produces enough energy for an EV to drive 710,250 miles. This is over 70 times the distance the same acre producing corn could provide.

Unlike ethanol, an acre of solar can power anything attached to the grid. The same Iowa acre, for instance, could also be used to provide 18 average US homes with electricity for the year. 

The financial utility of replacing corn with solar also promises huge gains for farmers. For example, it is not uncommon for a farmer to make two to three times more money per acre leasing to solar rather than planting corn. Solar also guarantees a steady stream of revenue, unlike corn which stands the risk of crop failure and price volatility. 


One Response to “Solar Much More Efficient Use of Land vs Ethanol”

  1. renewableguy Says:

    My uncle farming near the Mississippi river in Illinois has received a nice benefit from corn alcohol economy. Driving my Tesla Model S and charging at my mother’s home also on the farm he was ribbing me about not using corn. I just might bring up agrivoltaics to the family and see if it flies with them.

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