Ethanol Versus Water

Study finds that global warming will exascerbate the conflict between U.S. ethanol objectives and its water needs

1 min read
Ethanol Versus Water

Researchers from the United States, Europe, and China have concluded that as the earth warms over the next 40 years and rainfall patterns change, increasing ethanol production to meet U.S. mandates could strain supplies of irrigation water, especially in the northern Great Plains. Relying on a sophisticated agro-ecological model, GEPIC, and the IPCC's A2 greenhouse gas emissions scenario, the four scholars found that reaching a target of 15 billion gallons of corn ethanol per year would imply a 19 percent increase in irrigation water consumption, from 10.22 to 12.18 teraliters per year.

Considering that the increase takes place over a 40 year period, perhaps it is not unmanageable as such. But, as earlier studies by some of the same researchers have shown, the clash between ethanol production and water needs raises serious questions about the wisdom of U.S. biofuels strategy. As a Rice University press release put it earlier this week: "It takes 50 gallons of water to grow enough Nebraska corn to produce the amount of ethanol needed to drive one mile"—or, put in different terms, "The production of one liter of corn ethanol requires between 350 and 1400 liters of water from irrigation, depending on location."

The earlier studies found that switching from standard gasoline to corn ethanol yields little or no decreases in greenhouse gas emissions. That's consistent with a conclusion Spectrum also reached on the basis of interviews with experts. With U.S. production of natural gas and oil rising quite sharply, and its dependence on foreign fuels decreasing, the strain that ethanol production is putting on already sorely stressed water systems—on top of adverse impacts on global food prices—suggests that the U.S. ethanol program may be due for a critical review.

Photo: BanksPhotos/iStockphoto

The Conversation (0)
This photograph shows a car with the words “We Drive Solar” on the door, connected to a charging station. A windmill can be seen in the background.

The Dutch city of Utrecht is embracing vehicle-to-grid technology, an example of which is shown here—an EV connected to a bidirectional charger. The historic Rijn en Zon windmill provides a fitting background for this scene.

We Drive Solar

Hundreds of charging stations for electric vehicles dot Utrecht’s urban landscape in the Netherlands like little electric mushrooms. Unlike those you may have grown accustomed to seeing, many of these stations don’t just charge electric cars—they can also send power from vehicle batteries to the local utility grid for use by homes and businesses.

Debates over the feasibility and value of such vehicle-to-grid technology go back decades. Those arguments are not yet settled. But big automakers like Volkswagen, Nissan, and Hyundai have moved to produce the kinds of cars that can use such bidirectional chargers—alongside similar vehicle-to-home technology, whereby your car can power your house, say, during a blackout, as promoted by Ford with its new F-150 Lightning. Given the rapid uptake of electric vehicles, many people are thinking hard about how to make the best use of all that rolling battery power.

Keep Reading ↓Show less