AES Southland says gas-fired repowering would support renewables development

AES Southland Development LLC (AES SLD) is making progress with its November 2012 application with the California Energy Commission on the gas-fired Redondo Beach Energy Project.

On March 19, the company filed with the commission a copy of a letter it had just sent to the South Coast Air Quality Management District (AQMD) with additional information needed to complete the engineering evaluation of the Redondo Beach Energy Project (RBEP). 

In early March, Redondo Beach voters rejected a local proposal that would have probably prevented development of the new power plant. In Redondo Beach, Measure A would have rezoned the site of the gas-fired AES Redondo Beach plant and required the plant to shut down by the end of 2020.

AES SLD said it is developing RBEP to provide local capacity and to assist in the integration of renewable energy in support of California’s Renewable Portfolio Standard objectives. The RBEP’s design accomplishes the project objectives by being able to start up quickly, increase/decrease project electrical output quickly, efficiently generate electricity over a large range of output (120 to 500 MW), and capable of numerous start ups and shutdowns.

The existing Redondo Beach Generating Station’s (RBGS) current operations support grid reliability and stability, the company said. But the new RBEP avoids that plant’s long start time by achieving approximately 70% of the rated electrical output (about 360 MW) within 10 minutes of initiating a start up. RBEP also supports grid reliability by being able to operate fewer, smaller units over a wider output rate at a higher thermal efficiency than larger combined cycle or simple cycle peaking projects.

This new facility would replace larger gas-fired steam plant at same site

AES-SLD proposes to construct, own, and operate a new electrical generating plant in the City of Redondo Beach, Los Angeles County. The RBEP will be a natural-gas-fired, combined-cycle, air-cooled electrical facility with a net generating capacity of 496 MW and gross capacity of 511 MW. It will replace, and be constructed on the site of the RBGS. The development of RBEP includes the demolition and removal of the existing station, which will result in 38 acres of open space along the Redondo Beach waterfront.

As a combined-cycle, air-cooled plant it will use less than 18% of the fresh water used by the units it is replacing, and will eliminate the use of ocean water for once-through cooling (OTC) at the site. RBEP will be smaller in physical size and generating capacity than station it is replacing.

“The California Independent System Operator (CAISO) and the California Energy Commission (CEC) have recognized the importance of the Redondo Beach Generating Station location as part of the coastal OTC fleet that provides both energy and capacity to satisfy the western Los Angeles Basin Local Reliability Area requirements,” said the November 2012 application.

RBEP will consist of one power block composed of three natural gas combustion turbine generators (CTG), three supplemental-fired heat recovery steam generators (HRSG), a steam turbine generator (STG), an air-cooled condenser and ancillary facilities. The project will have the ability change its power output quickly, as much as 30% of its capacity per minute, which will allow it to rapidly respond and balance fluctuations in generation and demand in the western Los Angeles Basin. It will also have rapid start capability. RBEP will be able to start up and come on line in less than 10 minutes as compared to the existing Redondo Beach Generating Station, which has start times of up to 36 hours, the application noted.

The existing RBGS currently has four operating steam generating units (Units 5-8), an auxiliary boiler No. 17, and four retired units (Units 1-4). Dismantling of this equipment would begin in first quarter 2016 through the fourth quarter of 2016, leaving the administration building and the building housing Units 1–4 intact to screen Harbor Drive from the new power block construction site. Demolition of Units 5–8 would begin in 2019 during the final stages of construction of the new power block.

The commission website shows that the agency is shooting for a decision on the RBEP project in December 2013.

AES plants provide peaking capacity to Southern California Edison

Said the Feb. 27 annual Form 10-K report of parent AES Corp. (NYSE: AES): “In terms of aggregate installed capacity, AES Southland is one of the largest generation operators in California with an installed capacity of 3,941 MW, accounting for approximately 7% of the state’s installed capacity and 16% of the peak demand of Southern California Edison. The three coastal power plants comprising AES Southland are in areas that are critical for local reliability and play an important role integrating the increasing amounts of renewable generation resources in California.”

Thhe Form 10-K added: “All of AES Southland’s capacity is contracted through a long-term agreement, which expires in mid-2018 (the ‘Tolling Agreement’). Under the Tolling Agreement, AES Southland’s largest revenue driver is unit availability, as approximately 95% of its revenue comes from availability-related payments. Historically, AES Southland has generally met or exceeded its contractual availability requirements under the Tolling Agreement and often captures bonuses for exceeding availability requirements in peak periods.”

The other AES Southland plants are Alamitos (2,075 MW gross) and Huntington Beach (474 MW gross), with the current RBGS at 1,392 MW gross.

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.