Conventional power plants tax nation’s water supply, UCS says

National electric generation and water use have been on a “collision course” for years, according to a new Union of Concerned Scientists (UCS) report that urges “water-smart power.”

More than 40% of U.S. freshwater withdrawals are used for power plant cooling, according to the report. These plants also lose several billion gallons of freshwater every day through evaporation. Further, increasing demand and drought are putting a greater strain on resources, the report says.

The study urges a larger embrace of renewable sources and energy efficiency, along with dry cooling for power plants.

Under such a scenario, water withdrawals would drop by 97% from current levels by 2050, with most of that drop within the next 20 years. That approach would also cut carbon emissions 90% from current levels, mostly in the near term. A renewables path would also be a much cheaper path for consumers, the report found.

“As old plants are retired or retrofitted and new plants are built, we’ve got to untangle our competing demands for water and energy,” said Erika Spanger-Siegfried, co-author of the report and a senior analyst in the UCS Climate & Energy Program. 

“The choices we make in the near term to define the power sector of this century will affect water resources, our climate and long-term hydrology, and the power sector’s long-term resilience,” said Peter Frumhoff, UCS’s director of science and policy and chair of the project’s Scientific Advisory Committee.

“We set electricity and water on a collision course years ago. Now we must build a power system hard-wired not for risk, but for resilience,” Frumhoff said July 16.

Low water levels and high water temperatures can cause power plants to cut their electricity output in order to avoid overheating or harming local water bodies. Such energy and water collisions can leave customers with little or no electricity or with added costs because their electric supplier has to purchase power from elsewhere, as occurred during the past two summers.

Heat waves in 2011, 2012 put strain on many power plants

The report notes that the heat waves of 2011 and 2012 “shined a harsh light on the vulnerability of the U.S. electricity sector to extreme weather.”

During the 2011 drought in Texas, power plant operators trucked in water from miles away to keep the plants running.

In 2012 The Tennessee Valley Authority’s (TVA) Gallatin coal plant and Entergy’s (NYSE:ETR) Vermont Yankee nuclear plant were forced to either reduce their output or temporarily shutdown.

Also in 2012, low water levels and soaring water temperatures forced at least seven coal and nuclear plants in the Midwest alone—received permission to discharge even hotter cooling water, to enable the plants to keep generating.

“As the contest for water heats up, the power sector is no guaranteed winner,” UCS said in the report.  

In Utah, for example, a proposal to build a 3,000-MW nuclear power plant fueled grave concerns about the impact of the plant’s water use. And in Texas, regulators denied developers of a proposed 1,320-MW coal plant a permit to withdraw 8.3 billion gallons (25,000 acre-feet) of water annually from the state’s Lower Colorado River.

Two very vulnerable regions to energy-water disputes are the Southeast and the Southwest.

Both regions have seen energy-water conflicts, though for different primary reasons—water scarcity in the Southwest, and high water temperatures in the Southeast, the UCS said.

The Southwest is facing rapid population growth and rising electricity demand while water resources are declining.

The U.S. power sector is undergoing a massive shift, UCS said in the report. The electricity made from coal is shrinking while the power generated from natural gas and renewable energy is growing.

However, UCS argues in the report that not all low-carbon options are “water-smart.” Electricity mixes that emphasize carbon capture and storage for coal plants, nuclear energy, or even water-cooled renewables such as some geothermal, biomass, or concentrating solar could worsen rather than lessen the sector’s effects on water.

The title of the report is “Water-Smart Power: Strengthening the U.S. Electricity System in a Warming World.”

About Wayne Barber 4201 Articles
Wayne Barber, Chief Analyst for the GenerationHub, has been covering power generation, energy and natural resources issues at national publications for more than 20 years. Prior to joining PennWell he was editor of Generation Markets Week at SNL Financial for nine years. He has also worked as a business journalist at both McGraw-Hill and Financial Times Energy. Wayne also worked as a newspaper reporter for several years. During his career has visited nuclear reactors and coal mines as well as coal and natural gas power plants. Wayne can be reached at wayneb@pennwell.com.