Enough Water for Guzzling Coal, Nuclear Plants?

This summer we saw the beginnings of a conflict that’s bound to get worse. In the midst of the nation’s searing drought, farmers found they were at odds with the natural gas fracking industry because there wasn’t enough water to go-around.

US policy makers continue to overlook the implications of increasing water scarcity when they evaluate the use of coal and nuclear power, according to a report. If they considered the true costs of various electricity generation methods, solar and wind would have clear advantages that go beyond even producing clean energy.

The report is especially timely, given recent data suggesting that 20% of the world’s acquifers are overexploited.

The report, The Hidden Costs of Electricity: Comparing the Hidden Costs of Power Generation Fuels, prepared by Synapse Energy Economics Inc. on behalf of the Civil Society Institute and the Environmental Working Group, examines: coal, nuclear, natural gas, biomass, solar (PV and concentrating PV), and wind (onshore and offshore).

Even irrigating crops for biomass consumes lots of water – as much a 100,000 gallons of water to make 1 megawatt-hour of electricity, and coal and nuclear use as much as 50,000 and 60,000 gallons for the same amount of power, respectively.

Government and industry are "flying blind" in planning for continued reliance on fossil fuels, nuclear and industrial biomass, says Grant Smith, senior energy analyst at Civil Society Institute. "Each of these is water-intensive and leads to pollution of water,"and are "increasingly scarce and in competition for other uses such as agriculture and other commercial uses."

Water impacts have received relatively little attention compared with some of the other arguments that are used for or against these generation methods.

"In 2005 the Congress mandated a federal water/energy roadmap," says Seth Sheldon, lead water/energy analyst at the Civil Society Institute. "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. 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."

Coal Plants: Besides fouling streams and drinking water at mining and coal-ash dump sites, closed-loop coal-fired power plants withdraw 500-600 gallons of water per megawatt-hour (gal/MWh) of electricity produced. Withdrawals are substantially greater at  open-loop plants – 20,000-50,000 gal/MWh. Most of the water is recovered, but at a lower quality and higher temperature.

This is especially problematic in Asia, where rivers are being diverted for thirsty coal-fired plants. India and China are planning $720 billion new new coal generators over the next 20 years – that’s double the energy capacity of the US, according to the International Energy Agency.

Inner Mongolia’s rivers are feeding China’s coal industry, turning grasslands into desert. Thousands of farmers in India have protested the diversion of water for coal- fired power plants, some committing suicide, reports the NY Times.

The stage is set for conflict between farmers, industry and energy production – all because of water.

"The world has already hit ‘peak water,’" Simon Powell, head of Asian oil and gas research at CLSA told the NY Times. Demand is growing against a finite supply of fresh water that’s shrinking due to pollution and climate change."

Nuclear: The relationship between water and nuclear power generation also became clear this summer when searing drought forced some plants to temporarily shut down. Lots of water is necessary to keep nuclear rods cool. 

62% of US nuclear plants are closed-loop – they withdraw 700-1,100 gal/MWh, most of which is lost to evaporation. Open-loop systems consume 25,000-60,000 gal/MWh. 

Natural gas fracking not only fouls water supplies, but consumes an enormous amount of water – from 2-10 million gallons per well.

"The rush to drill for shale gas is one of the best recent examples of how the costs of water pollution are ignored in the pursuit of supposedly cheap energy," says Dusty Horwitt, senior counsel, Environmental Working Group. "When New York regulators estimate a price tag of $8-10 billion to build a water treatment plant for New York City if shale gas drilling contaminates its upstate water supply, it raises serious questions about whether shale gas really is so cheap and why water costs aren’t always considered from the start."

Natural gas generation uses much less water – less than 100 gal/MWh for drying cooling methods with 50-70 gal/MWh lost via evaporation (60% of US natural gas uses this method). Those that employ water towers use more than double the water – 230 gal/MWh, with 180 gal/MWh lost to evaporation.

Biomass plants also consume lots of water. A typical 50 megawatt (MW) withdraws 240 million gallons of water a year, losing most of that. The water demands of some dedicated energy crops are also considerable: one study estimates they require 40,000-100,000 gal/MWh.

Solar and Wind Sip Water when compared to other generation technologies. One study estimates water withdrawals at 225-520 gal/MWh, with thin film at the low end of that range and crystalline silicon at the high end.

One of the criticisms of concentrating solar is that water is needed to keep the surfaces clean – about 800 gal/MWh. Newer approaches are solving that problem – plants that employ "dry cooling" technology consume only 80 gal/MWh – about one-tenth that of nuclear power and one-sixth that of coal. 

Wind plants also consume very small amounts of water – 55-85 gal/MWh for both onshore and offshore farms.

Here’s the report: