Pacific Gas and Electric works on hydro project of up to 1,200 MW

Pacific Gas and Electric (PG&E) told the Federal Energy Regulatory Commission on May 30 that it is making progress on developing the 300 MW-1,200-MW Mokelumne Pumped Storage hydro project in California.

In December 2011, the commission had approved PG&E for a successive preliminary permit on this project, which allowed feasibility work to continue. The proposed project would be located on the North Fork Mokelumne River, Bear River and Cole Creek, in Amador and Calaveras counties, Calif.

The proposed project would consist of: the existing Lower Bear River Reservoir, with a surface area of 746 acres, storage capacity of 49,079 acre-feet, and normal water surface elevation of 5,822 feet mean sea level (msl), as the upper reservoir, with the possibility of a dam raise to increase capacity; a 16,000-foot-long power tunnel including intake structure and penstock; the existing Salt Springs Reservoir, with a surface area of 960 acres, storage capacity of 141,817 acre-feet, and a normal water surface elevation of 3,959 feet msl, as the lower reservoir; a powerhouse with a total installed capacity from 300 MW-1,200 MW; and a 230- or 500-kV overhead transmission line. The annual electrical production would be between 396 and 1,584 gigawatt-hours.

On May 30, PG&E filed its third six-month update with the commission on its work so far on this project. Recent work includes financing efforts and evaluation of how this pumped storage project would work to fill in gaps in power capacity available on the grid from intermittent renewable energy projects in the region. The company said it continued to participate in the California Public Utilities Commission’s 2012 Long-Term Procurement Plan process. In the fourth quarter of 2012, the company issued a request for information on energy storage technologies. It is also looking at how this project fits in with other proposed pumped storage projects in the region.

About Barry Cassell 20414 Articles
Barry Cassell is Chief Analyst for GenerationHub covering coal and emission controls issues, projects and policy. He has covered the coal and power generation industry for more than 24 years, beginning in November 2011 at GenerationHub and prior to that as editor of SNL Energy’s Coal Report. He was formerly with Coal Outlook for 15 years as the publication’s editor and contributing writer, and prior to that he was editor of Coal & Synfuels Technology and associate editor of The Energy Report. He has a bachelor’s degree from Central Michigan University.