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The Hetch Hetchy Power System

The Hetch Hetchy Power System generates and delivers hydroelectric, solar and biogas energy to retail and wholesale electricity customers in San Francisco. Specifically, the system consists of: 

  • 385 MW of Greenhouse Gas-Free Hydroelectric Generation Capacity
  • 11 MW of Renewable Solar, Wind, and Biogas Generation
  • 160 Miles of Clean Energy Transmission Lines

View our 2019 Power Content Label to better understand what type of energy we generate and where it comes from. (See 20182017, 2016).

Hetch Hetchy Power has also been certified as Climate Registered Gold status by The Climate Registry, an international non-profit organization that designs and operates voluntary and compliance greenhouse gas emissions reporting. Learn more about this prestigious honor.

View a map of the Hetch Hetchy Power System or click the image below.

Click on the map for a larger view of the Hetch Hetchy power system map 


The same force of gravity that propels your tap water across California, to your tap, is also harnessed to generate clean, 100% greenhouse gas-free Hetch Hetchy hydroelectric power. That’s right; your tap water powers MUNI’s electric buses. 150 miles before your Hetch Hetchy tap water gets to you, the very same water you use to quench your thirst has gone through turbines to generate clean energy for MUNI and a whole host of other City services. Hetch Hetchy powers all of the City’s municipal facilities (SFO, SFGH, MUNI, fire stations and more), residents and businesses in the San Francisco Shipyard, Treasure Island and other retail customers. In fact, your tap water powers nearly 20% of the City’s electricity needs.

The Hetch Hetchy Regional Power System is composed of three hydroelectric powerhouses: Moccasin Powerhouse, Kirkwood Powerhouse and Holm Powerhouse. The combined total hydroelectric generating capacity for these facilities is approximately 385 megawatts. Hydroelectric generation at Moccasin and Kirkwood Powerhouses rely on gravity-driven water flowing downhill from the Hetch Hetchy Reservoir. Holm Powerhouse generates energy from gravity-driven water flowing downhill from Cherry Lake. The SFPUC provides this energy to its retail electric customers, wholesale electric customers and in normal-to-high precipitations years, the SFPUC sells this energy on the California energy markets.

San Francisco benefits immensely from owning and operating the Hetchy Power system. Hetch Hetchy hydroelectric energy is cost-effective and 100% greenhouse gas-free. It does not produce any harmful radioactive byproducts or leave behind any waste. Its cost-effective, clean electricity keeps our environment clean and helps the City’s fiscal bottom-line.

The San Francisco Public Utilities Commission operates the City’s municipal solar photovoltaic (PV) installations located on City buildings and schools throughout the City including Moscone Center, City Hall and Davies Symphony. The SFPUC also purchases, under long-term contract, solar power from the Sunset Reservoir. Learn more about each of our solar arrays.

The SFPUC operates a cogeneration facility at the City’s Southeast Waste Water Treatment Plant. This plant takes methane gas (a major greenhouse gas emission source) generated as a by-product of the City’s water treatment to fuel an on-site generator to create renewable electric energy and significantly reduce overall greenhouse gas emissions. The rated capacity of this plant is 3,100 kilowatts.

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Last updated: 12/4/2020 10:27:05 AM