Analysis of US corn ethanol production

In 2024, American farmers harvested 14.9 billion bushels of corn with an average yield of 179.3 bushels per acre. About 5.5 billion bushels (approximately 37% of the harvest) went into fuel ethanol production. The US maintains its status as the world's largest ethanol producer.

Congress established the Renewable Fuel Standard (RFS) through the energy acts of 2005 and 2007 to combat rising fuel prices, greenhouse gas emissions, and dependence on oil imports. As a result, in 2006–2007, the area planted with corn grew from 78.3 million to 93.5 million acres.

The energy and climate balance of corn ethanol is contested by specialists. According to a 2022 analysis in the Proceedings of the National Academy of Sciences, taking into account land-use change, fertilizer application, and crop displacement, the carbon footprint of corn ethanol may exceed that of gasoline by at least 24%. In addition, pollution from growing corn in the US, including ammonia from fertilizers, is linked to approximately 4,300 premature deaths annually.

Other crops are being considered as alternatives. Trials in Alabama and Maryland have shown that industrial sweet potatoes are capable of producing more than twice as much ethanol per hectare compared to the average corn yield. Nevertheless, transitioning to them will require solving numerous agronomic, infrastructural, and economic challenges.