Water Needs Electricity Needs Water…

By Kevin Ferguson, New York Times

It has long been an axiom of infrastructure planning that it takes a lot of water to make electricity, and a lot of electricity to make water.

Each day, for example, the nation’s thermoelectric power plants (90 percent of all power plants in the United States), draw 136 billion gallons of water from lakes, rivers and oceans to cool the steam used to drive turbines, according to the Department of Energy. In recent years, the energy department says, plans for new power plants had to be scrapped because water-use permits could not be obtained.

For their part, water- and wastewater utilities consume at least 13 percent of the electricity drawn nationwide each day, according to River Network, an environmental group based in Portland, Ore. Such plants face increasing public pressure to cut energy costs and greenhouse gas emissions.

So it was of no small significance that Poseidon Resources last week managed to win approval from California state regulators to build the Western Hemisphere’s largest desalination plant, near San Diego.

Water is an increasingly scarce commodity in the West, so ocean desalination projects are attractive to city and regional planners. But desalination is also inherently energy-intensive, and it will take more electricity to desalinate water at the new facility than to import it from elsewhere, as the utility does now.

Indeed, San Diego Gas & Electric will produce 97,165 metric tons of carbon dioxide annually to supply the Carlsbad desalination plant with the 274,400 MWh of electricity it needs to produce 50 million gallons of drinking water each day for a year.

By comparison, pumping the same volume from the north requires 112,005 MWh; and pumping it from the Colorado River Aqueduct, San Diego’s secondary source of water, requires 167,900 MWh each year, according to the Natural Resources Defense Council.

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Source:  The New York Times