The Hoover Dam, which is made from 3.25 million cubic yards of cement and more than 150 million pounds of iron and steel, is capable of retaining up to 29 million acre-feet of water in Lake Mead. That’s equivalent to capturing two years of the entire flow of the Colorado River. The stored water is the lifeblood of many cities and towns in the American southwest.
As part of the dam, there are 17 hydroelectric turbines that collectively generate around 4 billion kilowatt-hours of electricity per year. That electricity is distributed to the states of Arizona and Nevada, the City of Los Angeles, Southern California Edison, the Metropolitan Water District of Southern California, and the cities of Glendale, Burbank, Pasadena, Riverside, Azusa, Anaheim, Banning, Colton, and Vernon. Boulder City, Nevada, which was created to house the workers who built the dam, also gets its electricity from the dam.
Advantages Of Pumped Hydro Storage
Hydroelectric power has many advantages. It is renewable and has no carbon emissions, but there is a catch. After the water passes through the turbines, it is discharged into the Colorado River and can no longer be used to make electricity until it is absorbed by the atmosphere, blown by prevailing winds upstream of the dam, falls as rain, and is redeposited in Lake Mead to begin the process all over again.
According to the New York Times, the Los Angeles Department of Water and Power has a better idea. It wants to build a pumping station about 20 miles downstream from Hoover Dam, recapture some of the water, and pump it back into Lake Mead where it can be used to generate more electricity once again. The proposed plan would cost about $3 billion.
The problem is that California has so much renewable energy available now, thanks in large measure to aggressive state mandated policies, that much of its is “constrained.” That’s utility industry speak for having to give it away or simply let it go to waste. In some cases, utilities in California actually pay other utility companies to take the excess electricity off their hands.
Why Not Use Battery Storage?
Why not store it all in some of Elon Musk’s grid scale batteries? Simply put, pumped hydroelectric storage is cheaper than battery storage, at least for now. Lazard, the financial advisory and asset management firm, estimates utility scale lithium-ion batteries cost 26 cents per kilowatt-hour compared with 15 cents for pumped hydro storage.
“Hoover Dam is ideal for this,” Kelly Sanders, an assistant professor of civil and environmental engineering at the University of Southern California tells the New York Times. “It’s a gigantic plant. We don’t have anything on the horizon as far as batteries of that magnitude.”
Sri Narayan, a chemistry professor at USC, says his studies of lithium ion batteries show they simply aren’t ready to store the loads needed to manage all of the wind and solar power coming online. “With lithium ion batteries, you have durability issues. If they last five to 10 years, that would be a stretch, especially because we expect to use these facilities at full capacity. It has to be 10 times more durable than it is today.” He says pumped hydro is preferable because it is a technology that has been tested and proven over decades of use.
The Devil Is In The Details
We reported recently on the permitting process a solar developer is going through in Westhampton, Massachusetts. That struggle is child’s play compared to what the LA Department of Water & Power plan will require. For one thing, Hoover Dam sits on federal land and is operated by the Bureau of Reclamation, which is part of the Interior Department. Environmentalists are concerned about the big horn sheep that graze below the dam.
Eric Garcetti, mayor of Los Angeles, is a strong advocate for clean energy. “Our challenge is: How do we get to 100 percent green?” he asks. “Storage helps. There’s no bigger battery in our system than Hoover Dam.” But LA Water & Power has made some enemies of late, people who could stand in the way of the Hoover Dam pump station proposal. Remember the words of TIP O’Neill about all politics being local? Oh, yeah. Big time.
Old Wounds Are Still A Problem
When the LA Department of Water & Power elected to shut down a coal-fired generating station in Laughlin, Nevada in 2006, 500 people lost their livelihoods and the local economy was devastated. People haven’t forgotten. “There’s nothing going on in California with power that has given people who are dealing with them any comfort,” says Nevada senator Joseph Hardy. “I think from a political standpoint, we would have to allay the fears of California, Nevada and Arizona. There will be a myriad of concerns.”
Some of those concerns involve aesthetics. Many people how live in the area or use the waters below the dam for sporting and recreational purposes are not thrilled about 20 miles of large diameter pipes cluttering up their view. And no politics in the American southwest are more fraught with conflict and danger than who gets to use the water in the lower Colorado River. Without that water, Phoenix and Los Angeles would shrivel back into desert communities. Farmers in both states are utterly dependent on water from the river for irrigation. LA officials will be pressed hard to prove their plan will not reduce the amount of available water.
Multi-state concerns. Federal jurisdictional issues. Old scores to be settled. Los Angeles has a tough road ahead if it wants to turn Hoover Dam into a giant battery. But there is hope. Mayor Garcetti says he is open to ideas that will benefit the entire region. “I’m all open ears to what their needs are.”
For his part, Senator Hardy says he is ready and willing to meet with Los Angeles officials to make the project successful, though he is skeptical of big city promises. The closure of the power plant in Laughlin still stings, more than a decade later. “The hurdles are minimal and the negotiations simple, as long as everybody agrees with Nevada,” he says. “It would be nice if there was a table that they would come to. I’ll provide the table.” Step into my garden, said the spider to the fly.