Water Sucking Solar Farms Breed Water Wars


A worker inspects a large mirror that directs the sun's energy to water-filled troughs at a solar thermal plant in the Israeli desert. Photo by Steve Jurvetson via Flickr.

If you thought there were water wars brewing before, just wait. The sun is often touted as a fantastic source of energy, which it is, but there's a hitch: Many solar projects consume enormous amounts of water. How much water are we talking? According to a recent New York Times article, proposed plans for two solar farms in Nevada would gulp up 1.3 billion gallons of water annually--or 20 percent of the area's available water. And the worst thing is this heavy water use in renewable energy projects is all about the bottom line.High-Profit Solar Technology Devours Water
According to The New York Times article, many solar developments are solar thermal plants, not solar cells like those you would find installed on roof-tops. Solar thermal plants use mirrors to heat water, which creates steam, which in turn drives turbines to generate electricity.

The water use comes in with the cooling process. Wet cooling consumes vast quantities of water is far cheaper than dry cooling, which uses fans to cool the water. Dry cooling is less efficient and there are added costs, so the profit margin is lower.

The push toward water-intensive green energy technology is a problem, Michael Webber, an assistant professor at the University of Texas in Austin, told The New York Times, "When push comes to shove, water could become the real throttle on renewable energy."

In Nevada, the issue flared up after a German company, Solar Millennium, proposed building two large thermal solar farms and revealed the process would require more than a billion gallons of water each year. Residents began to worry that their wells might dry up, and environmentalists sounded the alarm about the effect on ecosystems.

Other states are also dealing with this problem. Some local governments in California have refused to allow solar companies to draw huge amounts of water, forcing developers to use the more costly technology, and the legislature is now dealing with the battle between concerned residents and companies looking to make top profits.

Solar's Water Woes Hit California Legislature
Current California policy prohibits the use of drinking water for power plant cooling, but that could soon change.

A bill that has been introduced in the California Legislature would allow companies to draw on drinking water for their cooling process. While there are conditions, the shift in policy concerns residents, politicians and experts.

As California Energy Commission Deputy Director Terry O'Brien told The New York Times, water use would not even concern companies: "By allowing projects to use fresh water, the bill would remove any incentives that developers have to use technologies that minimize water use."

But more worrisome is the potential such a bill has to depress efforts to develop technologies that would allow for less water usage with increased efficiency and profits--technologies like the one developed by BrightSource Energy, which uses a tower system (as opposed to a trough) that employs efficient dry cooling.

In a world where areas are experiencing life-threatening drought, freshwater resources should be fiercely protected. This doesn't have to be to the detriment of solar power--it just means companies need to do a better job of developing technologies that are not reliant on high water use. Continuing down the water-depleting road we're on is irresponsible and unnecessary.

More on Solar Energy
How Does Solar Energy Work?
Here Comes the Sun: Increasing Incentives for Solar Energy
How to Go Green: Alternative Energy

Tags: California | Drinking Water | Electricity | Nevada | Solar Energy | Solar Power

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