At a facility 72 miles north of San Francisco, a powerful force deep underground is harnessed to supply almost five percent of California’s electricity. The facility, known as The Geysers, taps into a reservoir of steam over two miles below ground and turns it into usable electricity. Each year, this steam generates up to 5.5 million Megawatt-hours (MWh) of power, making The Geysers the largest geothermal field in the world.
Luckily for Santa Clara, we have invested in this renewable, reliable power resource. Through the Northern California Power Agency (NCPA), we co-own two geothermal plants at The Geysers. Together, our plants produce up to 240 MWh of power each year – enough to power as many as 240,000 homes among our combined customers.
How does it work? Like most geothermal plants, The Geysers collects naturally created high-pressure steam from underground “wells” and directs that steam into large turbines that turn to generate electricity. Since the flow of heat from the Earth is fairly constant, the plants are very reliable, producing steady power 24 hours a day.
But The Geysers is even more renewable and innovative than most geothermal plants: the facility also redirects wastewater headed for a recreational lake, treats it, and adds it to the geothermal wells. Solar-powered pumps are used to move the water from the wastewater plant and up over the hill to the geothermal facility. These resourceful efforts mean that little is wasted and the positive environmental benefits are multiplied.
The Geysers is one of the many diverse resources we use to power Santa Clara and provide carbon-free electricity to all residents. Through smart investments in innovative renewable power plants, we’re able to provide our customers with modern, affordable power solutions.