Building more geothermal power plants by the Salton Sea could eventually save Californians hundreds of millions of dollars per year, according to a new report.

The lake is home to one of the world’s most potent geothermal reservoirs, thanks to underground heat that brings salty water to temperatures greater than 500 degrees Fahrenheit. But while 11 geothermal plants already generate electricity along the Salton Sea’s southern shore, energy development has ground to a halt in recent years, due to the high cost of building geothermal facilities. Only one of those 11 plants opened after 2000.