California ISO suggests clutch systems for future combustion turbine projects

The California ISO wrote a Nov. 23 letter to the California Public Utilities Commission suggesting that the commission push for the installation of clutch systems on future combustion turbine projects as part of a grid reliability effort.

Said the Nov. 23 letter: “As you know, California is experiencing unprecedented changes in how electricity is generated, delivered and consumed. As increasing amounts of renewable resources come on line, we are encountering new challenges in maintaining grid stability. One of those challenges is that renewable resources, though they provide clean power to serve load, often do not provide the reactive power and inertia that is commonly supplied by gas-fired synchronous generators. As a result, when these services are needed, grid operators must inefficiently run carbon-intensive generators at minimum load.

“A low cost solution is to ensure that future gas-fired generation, where feasible, be designed with synchronous condenser capability. This capability can be accomplished with the installation of a clutch that enables the generator to disconnect from the gas turbine. The generator can then operate as a synchronous condenser, supplying essential reliability services needed for grid stability, without burning natural gas.

“Adding a clutch to a combustion turbine project increases the total installed cost by about 1%-2%. This modest investment is often prudent, in that it increases the optionality of the generator by enabling it to operate in synchronous condenser mode when required by system conditions. If clutches are not installed when combustion turbine projects are first constructed, and the grid later needs low-carbon sources of essential reliability services, retrofits or standalone synchronous condensers may have to be procured, at a cost of hundreds of millions of dollars.

“We thus request the Commission to consider making clutches a default option in procurement decisions related to new combustion turbine generation projects.”

The letter is signed by Steve Berberich, the California ISO’s President and Chief Executive Officer. The letter was also sent to members of the California Energy Commission.

The letter was inserted on Dec. 3 into the California Energy Commission’s docket for a 2012 application from AES Southland LLC for permission to construct and operate a power generation facility, the Huntington Beach Energy Project (HBEP), located in the City of Huntington Beach. The project will be located entirely within the footprint of the existing Huntington Beach Generating Station, an operating power plant. The HBEP is a proposed natural-gas fired, combined-cycle, air-cooled, 939-MW facility that will replace the existing plant. The letter was inserted by commission staff into this case as a potential point of discussion at a Dec. 8 site visit and hearing on this project.

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.