Summit Power Group buys, revamps Palmdale power project in California

Summit Power Group LLC has taken on the stalled Palmdale Hybrid Power Project in California from the city of Palmdale and plans major changes in the project, including the deletion of the solar part of this solar/gas project.

The California Energy Commission got two April 30 applications related to the new situation.

In one case, the parties are asking for permission to transfer a commission approval for the Palmdale Hybrid Power Project (PHPP) from the City of Palmdale to Palmdale Energy LLC. Palmdale Energy is a wholly owned subsidiary of Summit Power Projects Holdings LLC (SPPH). SPPH is owned by Summit Power Group LLC, a longstanding developer of energy projects in the U.S. On April 30, Palmdale Energy closed on a purchase and sale agreement with the City of Palmdale for the purchase of all rights, licenses, permits, options, etc. in existence for the PHPP.

Also on April 30, Palmdale Energy filed an amendment petition with the commission, proposing to eliminate the solar energy component of the project and reconfigure the two-on-one combined cycle power block configuration to incorporate new gas turbine technology to meet pending need for “Flexible Resources” to support integration of renewable energy.

In 2008, the City of Palmdale filed an Application For Certification (AFC) for a nominal 570-MW hybrid of natural gas-fired combined-cycle generating equipment integrated with solar thermal generating equipment. The combined-cycle equipment would have utilized two natural gas-fired combustion turbine generators (CTG), two heat recovery steam generators (HRSG), and one steam turbine generator (STG). The solar thermal equipment was planned to use arrays of parabolic collectors to heat a high-temperature working fluid. The hot working fluid would have been used to boil water to generate steam. The combined-cycle equipment was to be integrated thermally with the solar equipment at the HRSG and both utilize the single STG.

The commission approved the project in August 2011. It also approved two alternative generation tie-line routes.

Name being changed to Palmdale Energy Project

Palmdale Energy is now requesting that the PHPP name be changed to Palmdale Energy Project (PEP). The other project modifications proposed by this April 30 amendment request include:

  • Replacement of the General Electric gas turbines with new Siemens SGT6- 5000Fs to meet pending need for “Flexible Resources” to support integration of renewable energy.
  • Elimination of the solar components of the approved project.
  • Elimination of Brine Concentrator/Crystallizer systems.
  • Replacement of the wet cooling tower with an Air Cooled Condenser (ACC).
  • Reduction of the site from 333 acres to 50 acres.
  • Addition of a waste stream consisting of combustion turbine evaporative cooler blowdown, water treatment system reject, and plant drains.
  • Change in the water steam cycle chemistry control system from a phosphate-based system to an all volatile system.

“Palmdale Energy is acquiring the site in order to develop fast-start flexible generation to meet the changing California power demands, specifically to assist in the integration of renewable energy generated in California,” said the amendment application. “This change in technology could not have been anticipated during the original permitting process because at the time of the original licensing the PHPP was owned by the City of Palmdale whose objectives for the project were different. Palmdale Energy was not part of the original proceedings.

“The [California Independent System Operator] electric grid is undergoing significant transformation. The State of California has adopted renewable portfolio standards for electric utilities requiring that 33 percent of retail electric sales be served by renewable energy sources by 2020, which represents approximately 20,000 megawatts of capacity from new variable energy resources. Current estimates are by 2024 there may be 25,000 megawatts of capacity from variable energy resources.

“In addition, 12,079 megawatts of once through cooling resources will likely retire over the next eight years rather than meet environmental regulations. Further, California is currently examining policies to achieve 12,000 megawatts of distributed generation. CAISO studies show that to reliably operate the grid with this heightened level of uncertainty and variability, the CAISO will have an increased need for resources that can ramp up and down quickly and start and shut down potentially multiple times per day, i.e., flexible capacity. At the same time, the once-through-cooling retirements will reduce the number of existing resources that are available to provide the flexibility necessary to manage the increased variability and maintain day-to-day reliability.”

New version of the project will have a nominal output of 645 MW

The new PEP version of the project consists of gas-fired combined-cycle equipment utilizing two Siemens SGT6-5000F combustion turbine generators (CTG), two heat recovery steam generators (HRSG), and one steam turbine generator (STG). The modified project will have a nominal electrical output of 645 MW at average annual conditions and commercial operation is planned for summer 2019/summer 2020.

The Modified Project will be fueled with natural gas delivered via a new natural gas pipeline. Southern California Gas (SCG) will design and construct the approximately 8.7-mile pipeline in existing street rights-of-way (ROW) within the City of Palmdale.

The PEP plant site is located south of East Avenue M in the northernmost areas of the City of Palmdale. The 50-acre plant site was formerly part of an approximately 600-acre city-owned property that is bounded by Sierra Highway to the west, East Avenue M (Columbia Way) to the north, and U.S. Air Force Plant 42 on the south and east. Air Force Plant 42 is a Government Owned Contractor Operated (GOCO) facility for the production, engineering, final assembly and flight testing of high performance aircraft.

The proposed interconnection point for the PEP with the Southern California Edison (SCE) electrical transmission system is at SCE’s existing Vincent Substation south of Palmdale. This April 30 petition proposes a minor modification to one of the approved generation tie-line routes by extending westerly approximately 1,800 feet along the south side of East Avenue M to accommodate a change in the switchyard location.

Overall, annual availability of the PEP is expected to be in the range of 90% to 95%. The plant’s capacity factor will depend on the provisions of bilateral power sales contracts, as well as market prices for electricity, ancillary services, and natural gas.

The “Flex 30” fast start plant concept offered by Siemens Energy allows for faster starting of the gas turbines by mitigating the restrictions of former HRSG designs. Traditionally, the CTGs are brought to full load slowly to limit combined stresses in the high-pressure steam drum of the HRSG, due to the exhaust temperature of the CTGs. The new Siemens design incorporates their “drum plus” concept for the HP steam drum which reduces startup limits imposed by traditional HP drums. Additional equipment to support the fast start plant includes an auxiliary boiler, which will supply sealing steam and allow startup of the steam turbine, shortly after the gas turbines.

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.