Hoover Dam helped transform the American West, harnessing the force of the Colorado River — along with millions of cubic feet of concrete and tens of millions of pounds of steel — to power millions of homes and businesses. It was one of the great engineering feats of the 20th century.
Now it is the focus of a distinctly 21st-century challenge: turning the dam into a vast reservoir of excess electricity, fed by the solar farms and wind turbines that represent the power sources of the future.
The Los Angeles Department of Water and Power, an original operator of the dam when it was erected in the 1930s, wants to equip it with a $3 billion pipeline and a pump station powered by solar and wind energy. The pump station, downstream, would help regulate the water flow through the dam’s generators, sending water back to the top to help manage electricity at times of peak demand.
The net result would be a kind of energy storage — performing much the same function as the giant lithium-ion batteries being developed to absorb and release power.
Because the sun does not always shine, and winds can be inconsistent, power companies look for ways to bank the electricity generated from those sources for use when their output slacks off. Otherwise, they have to fire up fossil-fuel plants to meet periods of high demand.
And when solar and wind farms produce more electricity than consumers need, California utilities have had to find ways to get rid of it — including giving it away to other states — or risk overloading the electric grid and causing blackouts.
“I think we have to look at this as a once-in-a-century moment,” said Mayor Eric M. Garcetti of Los Angeles. “So far, it looks really possible. It looks sustainable, and it looks clean.”
The target for completion is 2028, and some say the effort could inspire similar innovations at other dams. Enhancing energy storage could also affect plans for billions of dollars in wind projects being proposed by the billionaires Warren E. Buffett and Philip F. Anschutz.
But the proposal will have to contend with political hurdles, including environmental concerns and the interests of those who use the river for drinking, recreation and services.
In Bullhead City, Ariz., and Laughlin, Nev. — sister cities on opposite sides of the Colorado, about 90 miles south of the dam — water levels along certain stretches depend on when dams open and close, and some residents see a change in its flow as a disruption, if not a threat.
“Any idea like this has to pass much more than engineering feasibility,” Peter Gleick, a co-founder of the Pacific Institute, a think tank in Oakland, Calif., and a member of the National Academy of Sciences, internationally known for his work on climate issues. “It has to be environmentally, politically and economically vetted, and that’s likely to prove to be the real problem.”