Water use in electricity generation: the sobering facts that make a case for wind and solar power
Did you know it takes 100,000 gallons of water to produce a single megawatt hour of electricity? Well according to a new report out today, it does – unless you’re using wind or solar power that is. So maybe, with much of the world battling more regular bouts of drought and water shortages it’s something policy makers need to start taking more notice of? The proponents of the report from Synapse Energy Economics - prepared for the nonprofit and nonpartisan Civil Society Institute (CSI) and the Environmental Working Group – certainly think they should. These groups warn that the huge demands on increasingly scarce water are “a major hidden cost” of a business-as-usual approach to American electricity generation. The report, The Hidden Costs of Electricity: Comparing the Hidden Costs of Power Generation Fuels, analyses six fuels used to generate electricity --- biomass, coal, nuclear, natural gas, solar (photovoltaic and concentrating solar power), and wind (both onshore and offshore). Water impacts, climate change impacts, air pollution impacts, planning and cost risk, subsidies and tax incentives, land impacts, and other impacts are all considered. With many – but not all - of the key energy technologies used today relying heavily on water, the headline findings make for fascinating reading:
The water saving options“By contrast, wind and solar photovoltaic power require little water in the electricity generation process”, it continues. Concentrating solar power requires water for cooling purposes, but new technologies are placing greater emphasis on dry cooling.
Estimates of the lifecycle water withdrawals from wind projects, including both onshore and offshore projects, range from just 55 to 85 gallons per MWh. Of course, neither wind power nor solar PV provide the answer to all our energy needs alone – and they both present issues for the electricity system generally and for policy makers. But with both sectors going through a tough period of uncertainty right now (in the US and elsewhere) maybe it’s time water usage was a more significant consideration when it comes to forming energy policy. Afterall, as Seth Sheldon PhD, CSI lead water and energy analyst notes, it was way back in 2005 that the US Congress mandated a federal water/energy roadmap. “Nearly eight years later, that roadmap has not been produced and either through bureaucratic inertia or fear of hard political questions, the questions are not even being asked, much less their solutions explored,” he says. “At a time of significant water scarcity and increasing threats to water quality, we can ill afford to ignore this central question about the future of our energy choices." He’s right of course.
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