NRG unit terminates 435-MW repower proceeding for California plant

El Segundo Energy Center LLC, owner of the El Segundo Energy Center (ESEC), filed with the California Energy Commission on Aug. 2 a termination notice for a suspended Petition to Amend (PTA) for proposed units 9-12.

The brief notice said: “Project Owner requested to suspend the processing of the PTA on February 18, 2016; the suspension was granted by the PTA Committee on March 8, 2016. Since the suspension, Project Owner has closely evaluated a number of factors that led to the suspension and have concluded that the best course of action is to terminate the PTA because of contractual obligations and a lack of near-term need for the Project which make it problematic for them to continue with this PTA.”

The notice added: “Project Owner continues to operate ESEC in compliance with the ESEC Final Decision as amended. CEC staff has supported Project Owner with the ongoing implementation of the ESEC Conditions of Certification, and we look forward to continued open and cooperative communications with CEC Staff regarding the facility.”

The El Segundo Energy Center unit of NRG Energy (NYSE: NRG) said in a brief Feb. 18 notice filed with the commission that it is freezing two amendment applications for the latest phases of this gas-fired repowering.

Said the Feb. 18 notice. “This letter serves as notice that ESEC LLC hereby suspends the PTAs for confidential internal business reasons. Notwithstanding the suspension affected by this notice, ESEC LLC will inform the Commission within six months whether it intends to pursue modified amendments or to withdraw the respective PTAs in their entirety.”

Looking at the suspended PTAs:

December 2015 application

Under the December 2015 PTA, the company proposed to make modifications to specified equipment licensed under a July 2010 commission decision. This petition to modify entailed the replacement of thermal insulation on steam turbine (ST) casings and installation of weatherization enclosures (i.e., ST weatherization enclosures) over the ESEC steam turbines, located at 301 Vista Del Mar, El Segundo, California.

The ESEC units consist of two 1×1 (one gas turbine generator (GTG) and one HRSG and ST generator (STG)) combined cycle power blocks. The STs were designed and installed with a spray on thermal insulation and hard shell (plaster-like) coating on the exterior of the ST casing that also encapsulated numerous valves, electric heating mats, and various sensors.

ESEC project online date was in August 2013. During 2014 the ST casing electric heater mats began to fail prematurely. The failed heater mats were scheduled to be replaced during the 2015 spring outage. During the outage the hard shell spray on thermal insulation was removed. The removal process of the thermal insulation coating damages the coating and requires the coating be reinstalled, a process that takes several days to accomplish. The thermal spray on coating also requires several days of “curing” before the ST could be placed back into service.

NRG notified the commission on June 1 that it wanted the weatherization suspension lifted and for this application to proceed, but that it wanted to keep the suspension in place for a repowering, which had been applied for in an April 2013 PTA. The April 2013 PTA is the subject of the Aug. 2 termination letter.

April 2013 application 

Chief among the changes proposed in this application was the replacement of two once-through-cooled boiler units, Units 3 and 4, with modern and efficient, dry-cooled, natural-gas-fired combustion gas turbine units. This change would eliminate the use of ocean water for once-through cooling at the facility. The proposed changes will also upgrade and improve the ESEC’s existing and approved site infrastructure, and provide fast start and dispatch flexibility capabilities to support southern California grid load balancing and renewable energy integration, and implement improvements to coastal access.

Specific changes proposed through this PTA included:

  • Shutdown and demolition of Units 3 and 4;
  • Removal and remediation of existing ESEC retention basins;
  • Change in location for the permitted (but not yet constructed) administration building to a lower elevation;
  • Construction of a new, combined administration, maintenance, and operations support building;
  • Modifications to existing site access; and
  • Improvements to beach access.

The following new major equipment was to be installed under this amendment;

  • One NRG fast start combined-cycle unit (CC Fast), rated at 325 MW (net), incorporating a General Electric 7FA.05 natural gas turbine;
  • Two Rolls Royce Trent 60 DLE ISI, rated at 55 MW/unit net, consisting of advanced aeroderivative simple-cycle gas turbines; and
  • One Cleaver Brooks 36 MMBtu/hr auxiliary boiler.

This latest project was to provide fast-start and dispatch flexibility capabilities through the installation of Units 9, 10, 11, and 12, adding approximately 435 MW (net) / 449 MW (gross) of new generation to the existing 560 MW (net) / 573 MW (gross) ESEC, identified as Units 5 through 8. Operation of Units 5 through 8 and proposed Units 9 through 12 was to result in a total generating capacity of approximately 995 MW (net) / 1,022 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.