Don’t Blame Fracking for California’s Water Woes

on April 10, 2015 at 11:00 AM
Drought Dries Up California Groundwater Sources

Low water levels at recharge ponds in San Jose, California. (Photo by Justin Sullivan/Getty Images)

It’s inevitable. In comments to nearly every story about California’s drought, someone will rage that if Gov. Jerry Brown really wanted to do something to save water, he’d put an end to fracking in the state.

This line of thinking was highlighted on social media recently when the Sierra Club tweeted a link to a Reuters report in which the state’s chief oil and gas regulator revealed that fracking consumed 70 million gallons of water in California in the past year. Hundreds of retweets followed, many from people outraged at the apparent water waste.

Just one problem: 70 million gallons is, in the grand scheme of California H2O, a proverbial drop in the bucket. As Vocativ calculated, California would save that much water “if about 10 percent of the state’s 39 million people took one fewer shower a year.”

Or think of it this way: A recently opened solar power plant in the Mojave Desert is authorized to use ten times that much water every year.


Commissioned just a few months ago, the Abengoa Mojave Solar plant is a rare solar bird in these days of cheap photovoltaics – it uses concentrating technology to produce thermal power. Long rows of parabolic troughs focus the sun’s energy on tubes that run along the length of the troughs. A synthetic fluid flows through the tubes, capturing the heat, which is then used to boil water. From there, a steam-turbine generator produces electricity.

abengoa mojave image

A rendering of the Mojave Solar project. Photo credit: Abengoa

As with any thermal generation scheme, there’s a need to cool the exhaust steam from the turbines. Mojave Solar accomplishes this by pumping cool groundwater from the aquifer beneath the Harper Dry Lake Basin, where it is located. The plant is approved to use 2,160 acre-feet of water per year, or 703,839,086 gallons.

Concentrating solar power doesn’t have to be so water intensive. “Dry cooling” systems, using air instead of water for cooling, consume about a tenth as much water. The Ivanpah plant, which uses tower technology instead of parabolic troughs but is a solar thermal plant all the same, uses dry cooling. So why didn’t they do that at Abengoa Mojave Solar?

Because dry cooling is less efficient and demands more “fuel” – in this case, sun power – to produce the same amount of energy. That drives up the cost of the electricity, and Abengoa Mojave Solar was already really expensive. When the plant’s power purchase agreement was approved in 2011 by the California Public Utilities Commission, Commissioner Mike Florio, the lone “no” vote, railed, “We could probably get almost 500 megawatts of renewable energy for the price we’re paying for this 250 megawatts.”

PPA prices aren’t disclosed, but electricity from Abengoa Mojave Solar is probably being sold to Pacific Gas & Electric for around 20 cents per kilowatt-hour. Research by the Lawrence Berkeley National Lab shows utility-scale photovoltaic PPAs edging toward 10 cents/kWh in 2011.

Abengoa has tried to characterize its Mojave plant as a water saver, since the 1,700-plus acres it occupies had once been used to farm alfalfa, an insanely thirsty crop that statewide uses about 15 percent of the water that flows to California agriculture.

But of course, that old alfalfa acreage could also have been covered in photovoltaic panels. PV – and wind, too, by the way – uses practically no water, which is why it is widely seen as a way to make the energy sector less water-intensive. As the National Renewable Energy Lab wrote in a 2011 report: “Non-thermal renewable technologies, such as wind and PV systems, consume minimal amounts of water per unit of generation.”

A fine example is the recently commissioned 550-MW Desert Sunlight power plant in California. It’ll use around 65,000 gallons of water a year, mostly to keep its photovoltaic panels shiny clean – less than one-tenth the water Mojave Solar will consume. And it will do so while producing twice as much electricity.