Low-carbon energy options that increase water consumption could be swapping one problem for another. That's the premise of an analysis reported by researchers at DOE's Idaho National Laboratory. They assessed the water footprint of numerous near-term energy generation options and found some surprising results.
Water is an essential component of many types of energy production. Even wind and solar energy have water footprints because they typically require coal, nuclear or natural gas backup to ensure electricity is available when sun or wind is not. Greenhouse gas emission discussions rarely consider water use, which could be the factor tipping support in favor of one approach or against another.
An INL study published in a 2012 issue of Environmental Science & Technology is one of the first to analyze how various carbon-curbing technologies impact water resources. It has attracted international interest because its findings could help inform far-reaching decisions about sustainable energy generation options.
For example, replacing gasoline with ethanol made from energy crops would greatly increase the water required to make vehicle fuel. Yet significant water savings could be realized by replacing coal-fired power with electricity fueled by natural gas. Increasing efficiency and reducing demand also are win-win-win in terms of cost, carbon emissions and water impacts.
"In discussions about climate change, various solutions are often presented as equal, but they all have a very different type of impact," says INL research scientist and study co-author Craig Cooper. "We've got to consider not just the cost or the climate, but think about it all in the context of being better stewards."