USA: Growing corn for ethanol increases CO2 emissions by 24%.

  • 2005: The US programme to grow corn for ethanol as fuel for cars is launched.

The official aim was to reduce pollutant and CO2 emissions from oil. For many, however, it was driven by a desire to provide Midwestern farmers with a new and more lucrative market for corn, thanks to incentives to keep the fuel from costing more than gasoline.

In 2000, only 400,000 tonnes of agricultural ethanol were produced in the US. In 2019, this figure peaked at 4 million tonnes, produced on around 10 million hectares of land.

How many CO2 emissions has it saved?

In fact, they have increased – growing maize for ethanol increases CO2 emissions by around 24%, as well as damaging land and water through pollution.

The result? What you save by not burning petroleum derivatives in your car, you emit by growing, transporting, fermenting and distilling corn into ethanol.

Despite these less-than-stellar results, the programme can no longer be stopped because too many farmers are now dependent on the incentives it provides.

What about replacing it with Agro-voltaics?

John Fitzgerald Waever, developer of large-scale solar power plants, has launched a campaign to solve the problem at its root: install solar panels in place of the corn crops used to fuel cars, eliminate the corn and cover those 10 million hectares with panels, considering their annual yield of about 1,000 MWh per hectare.

In this case, it would produce as electricity about 200 times the energy contained in corn ethanol, enough to cover 3.5 times all US electricity consumption, Fitzgerald says.

It is also possible not to turn agricultural land into an expanse of panels, but to make it coexist with agri-voltaic techniques.

In any case, farmers, through electricity production, will have a sufficient income supplement to be able to survive by continuing to do their work, no longer depending on environmentally harmful incentives.

Fitzgerald has probably overestimated the Midwest’s solar yields, which would be more in the region of 600MWh/ha/year (rather than the 1,000 he assumed), but the proposal remains an important starting point to think about and makes us realise that the integration of PV and agriculture can be an asset in the energy transition.