Skip to main content

Pacific Gas and Electric Company

Advanced Underground Compressed Air Energy Storage


Pacific Gas and Electric Company’s (PG&E) advanced underground, compressed air energy storage (CAES) demonstration project is intended to validate the design, performance, and reliability of a CAES plant rated at approximately 300MW with up to 10 hours of storage. The CAES demonstration project is scoped to test the suitability of a porous rock formation as the storage reservoir in California, and demonstrate the technological improvements in the design of such plants. Porous rock formations are much more plentiful than the salt domes now used by the two operational plants in Alabama and Germany. If this geology is proven viable, this technology has the potential to be replicated throughout California and elsewhere in the United States. The project is also differentiated by its potential use of a new CAES plant design that is much more efficient than first generation Alabama and German designs. This project is comprised of three phases. Phase I includes site selection, reservoir testing, preliminary plant design, an environment assessment and a competitive solicitation to determine if there are interested and viable parties for plant construction, ownership and operations/maintenance. Phase I is estimated to last 4.5 years. Phase II, which includes obtaining approval to proceed with the construction and commissioning of a full CAES plant, has an estimated 6-year duration. Phase III includes operations & monitoring and is expected to occur over 2 years.

Contact Information

Kimberly Nuhfer
Project Manager
National Energy Technology Laboratory
3610 Collins Ferry Road
Morgantown, WV 26507-0880

Michael Medeiros
Principal Investigator
Pacific Gas & Electric Company
77 Beale Street, B5Q
San Francisco, CA 94105-1814

Recipient: Pacific Gas and Electric Company
HQ State: California
NERC Region:
Total Budget: $355,938,300
Federal Share: $25,000,000
Funding Program:
Project Type:
Targeted Benefits:
  • Approximately 475 jobs created or retained during facility construction
  • Approximately 25 permanent jobs created to operate the facility
  • Greenhouse gas emissions reduced
  • Grid reliability improved

The Department of Energy's Office of Electricity (OE) recognizes that our nation's sustained economic prosperity, quality of life, and global competitiveness depends on an abundance of secure, reliable, and affordable energy resources. OE leads the Department of Energy's efforts to ensure a resilient, and flexible electricity system in the United States. Learn more about OE >>

None:prod None build None