Water costs on various forms of power generation are being underestimated by policymakers and the public, according to a new Synapse Energy Economics Inc. report prepared for the Civil Society Institute (CSI) and the Environmental Working Group (EWG).
The analysis, “The Hidden Costs of Electricity: Comparing the Hidden Costs of Power Generation Fuels,” analyzes six fuels – biomass, coal, nuclear, natural gas, solar and wind – in the following categories: water impacts, climate change impacts, air pollution impacts, planning and cost risk, subsidies and tax incentives, land impacts, and other impacts.
The report discloses the following:
- Nuclear power has critical cooling requirements that require huge amounts of water. Roughly 62 percent of U.S. nuclear plants have closed-loop cooling systems. Reactors with closed-loop systems withdraw between 700-1,100 gallons of water per MWh and lose most of that water to evaporation. Water withdrawals are even higher at open-loop cooled nuclear plants, which need between 25,000-60,000 gallons per MWh. Most of the water is returned, but at a higher temperature and lower quality.
- Coal-fired power relies heavily on closed-loop cooling systems which withdraw between 500 and 600 gallons of water per MWh and lose most of this via evaporation. Withdrawals for open-looped cooled coal-fired power plants are between 20,000-50,000 gallons per MWh. Most of the water is returned, but at a higher temperature and lower quality.
- A typical 50 MW biomass plant could withdraw roughly 242 million gallons of water per year and lose most of this. Adding 10 of these plants in a region would use 2.42 billion gallons of water per year.
- Wind and solar photovoltaic power requires little water in the electricity generation process. Concentrating solar power requires water for cooling purposes, but new technologies are placing greater emphasis on dry cooling. Solar power plants with dry cooling use only around 80 gallons per MWh – about a tenth of the low-end estimate for nuclear power and one-sixth of the low end estimate for coal-fired power generation.
Read the entire report here.
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