SMUD Adds 100 MW of Geothermal to its Power Portfolio

The Sacramento Municipal Utility District will receive 100 MW of geothermal energy from Calpine’s 725 MW facility in Sonoma County starting in January. In addition, SMUD will receive 100 MW of carbon-free resource adequacy.

“SMUD is on course to eliminate all carbon emissions from the power supply by 2030, and our new partnership with Calpine and The Geysers brings us a step closer to that vision,” SMUD CEO and General Manager Paul Lau said April 4.

SMUD’s board agreed to the 10-year agreement last month.

Annually, the muni is expected to reap 876,000 MWh of geothermal baseload power, which will supply about 97,000 homes, SMUD spokesperson Gamaliel Ortiz told Current.

SMUD’s 2030 Zero Carbon Plan considers geothermal power an essential component of its clean power portfolio. According to the muni, its power portfolio, which includes large hydropower resources, was 60% carbon-free in 2020.

CPUC orders more geothermal

The California Public Utilities Commission directed the investor-owned utilities, community energy and some other energy providers last June to buy 1,000 MW of new geothermal as part of its order to procure a total 11.5 GW of non-fossil fueled power between 2024-26. SMUD is not under the CPUC authority but is pursuing geothermal power on its own volition.

The CPUC’s decision refers specifically to firm zero-emissions energy with 80% capacity, which translates into geothermal power.

In late March, Sonoma Clean Power requested offers for 500 MW of geothermal power from Sonoma and Mendocino counties to help meet the CPUC directive. It is partnering with Silicon Valley Clean Energy and Central Coast Community Energy. Sonoma’s share is 150 MW of power that can help fill in electricity supply shortages when the sun sets.

“An increasing penetration of intermittent renewables, ambitious environmental targets, and retirement of nuclear and natural gas plants are creating an attractive market for the reliability and capacity attributes of geothermal power,” according to Sonoma's March 25 proposal seeking 500 MW of heated earth energy. Responses are due April 29.

The Geysers is the largest geothermal facility in the world, covering about 45 miles, according to Calpine.

The company is working to increase the output at The Geysers and expand it.

Added generation there “may take the form of new traditional geothermal production, new technologies specifically targeted at efficiently harnessing the heat of the resource, like the GreenFire technology, or a combination of these technologies and battery storage,” company spokesperson Danielle Matthews Seperas wrote in an email.