Calpine seeks California okay for greenfield 300-MW gas/battery project

The Mission Rock Energy Center LLC unit of Calpine Corp. (NYSE: CPN) proposes to construct, own, and operate a power plant in Ventura County, California, called the Mission Rock Energy Center (MREC).

The company on Dec. 30 filed with the California Energy Commission an Application for Certification (AFC) of this project. It will be a natural gas-fired, simple-cycle combustion turbine facility rated at a nominal generating capacity of 275 MW, co-located with battery units for the storage of electricity that can deliver an additional 25 MW. The MREC will also be fitted with a clutch system so that it can provide voltage support by operating as a synchronized condenser.

Mission Rock filed this AFC under the California Energy Commission’s 12-month licensing process. Construction of the MREC is expected to begin in November 2018. Pre-operational testing of the power plant is expected to begin in April 2020, and full-scale commercial operation is expected to begin by September 2020.

The MREC’s primary objective is to combine dispatchable, operationally flexible, and efficient energy generation with state-of-the-art energy storage technology, to meet the need for new local capacity in the Moorpark Subarea of the Big Creek/Ventura local reliability area of Southern California Edison’s (SCE’s) service territory. The same energy storage system that provides MREC with black start capability will also provide an additional 25 MW/100 MW hours of flexible, preferred resource capacity to the grid.

The energy storage system will be used to store energy during times of over-generation, which may be caused by intermittent renewable generation, and delivered back to the grid when needed. Operationally flexible resources are increasingly needed to assist with the integration of intermittent renewable resources, such as solar and wind facilities, for grid operation. Additionally, peaking capacity is needed to respond to increases in the local demand for electricity that typically occur in the afternoons of summer days. The MREC is expected to run intermittently and provide real-time energy and voltage support to the grid.

The MREC will have the ability to start and achieve full capacity in 10 minutes. The MREC will have black start capability provided by the energy storage system, which allows the facility to come online and support the grid to recover from a complete outage. The same energy storage battery system that provides the MREC with black start capability will also provide an additional 25 MW/100 MWh of flexible, preferred resource capacity to the grid.

The California ISO has identified a near-term need for new power facilities that can support easily dispatchable and flexible system operation. The MREC’s objectives are consistent with this need as follows:

  • Safely construct and operate a 275 MW, natural gas-fired, simple-cycle generating facility with energy storage capabilities to meet SCE’s need for local capacity due to the retirements of the once-through cooling plants in the Moorpark sub-area of the Big Creek/Ventura local reliability area of Southern California;
  • Site the project as near as possible to a SCE substation with available transmission capacity to serve the Moorpark Subarea; and
  • Site the project in an existing industrial area on a brownfield site, to minimize environmental impacts.

The MREC site is located in unincorporated Ventura County, west of the City of Santa Paula, at 1025 Mission Rock Road. The MREC site is a 9.79-acre parcel currently used for recreational vehicle and boat storage which is almost entirely paved with asphalt-concrete. Adjacent land uses include the Granite Construction Co. asphaltic concrete plant and asphalt recycling facility, several automobile dismantling facilities, vehicle storage for crushed cars, auto repair and salvage yards, an oil and gas well and processing equipment, and agricultural production.

MREC will interconnect to the SCE Santa Clara Substation via a new 6.6-mile, 230-kV transmission line located approximately 4.5 miles west of the MREC site. The natural gas line interconnection for the power plant entails constructing approximately 2.4 miles of new 16-inch pipeline directly southwest from the project site to the point of interconnection with the Southern California Gas high-pressure natural gas transmission lines 404/406. Service water will be provided from a new 1.7-mile-long pipeline connecting to the Limoneira Co.’s recycled water pipeline southwest of the MREC site. Process wastewater will be discharged to an existing pipe in Shell Road, adjacent to the MREC site, for disposal by Green Compass.

Project to be based around five GE gas turbines

Selection of the power generation technology focused on those technologies that are optimized for peaking power generation and to use natural gas readily available from the existing distribution system. The General Electric LM6000 PG combustion turbine technology was selected primarily because it is proven, reliable equipment that also provides operational flexibility. The configuration of five LM6000 PG units provides a well proven technology that is flexible in operation, efficient, cost effective, and easily dispatchable. The factors considered in selecting LM6000 units included the following:

  • High reliability/availability – The LM6000 gas generator has an overall reliability of 99.42% and package availability of 98.36%, based on GE data.
  • Low equivalent forced outage rate – The LM6000 had an equivalent forced outage rate of 1.43% from November 2004 to July 2007.
  • Mission Rock’s parent company, Calpine, owns and operates a fleet of twenty LM6000s, including fifteen LM6000 units in peaking service in California. Operation and maintenance advantages will accrue to the MREC by maintaining consistency with Calpine’s fleet of LM6000 units.
  • The LM6000 configured at 275 MW has the significant advantage of shaft redundancy. Because there will be five CTGs, the plant can ramp up to full load with minimal air emissions by successfully starting the CTGs and ramping them up to full load quickly. The units can also be shut down successively to follow reduced load.

The GE LMS100 combustion turbine technology was also considered for MREC. Based on the nominal 100 MW output of these units, either 200 MW (two units) or 300 MW (three units) configurations would be feasible to achieve the desired output for MREC. Using the LMS100 turbines, however, would reduce the ability to operate at varying low loads at the optimal full-load heat rate for each unit. Partial loading of larger turbines would decrease operating efficiency and increasing emissions of GHGs per MW of generation.

With the proposed LM6000 configuration, MREC will have five optimal operating points between 0 MW and 275 MW rather than only two or three with an LMS100 configuration. In addition, because it uses intercooler technology, the LMS100 would require significantly more water to operate, and a large cooling tower or air-cooled condenser structure.

Mission Rock also considered choosing a large frame industrial turbine for the MREC. Several models are available in the 250 MW to 300 MW range with 10 or 12 minute startup times. This power output is achieved by using a single-turbine shaft, however, so that the LM6000 advantages of multiple-shaft ramping operation, shaft-redundancy, increased efficiency, and reduced GHG emissions would not be realized. Large frame industrial turbine technology is more appropriate for applications where potential future conversion to combined cycle is a consideration, than for peaking, load-following, and grid support operations.

MREC is a simple-cycle power plant that does not generate steam that would require a large cooling tower or air-cooled condenser. Therefore, cooling requirements are limited to CTG lubricating oil systems and inlet air cooling.

  • The lubricating oil system will use a fin-fan cooler to reduce the temperature of the lubricating oil. This system functions similar to an automobile radiator where the oil is passed through a “radiator” as air is passed through the cooling fins.
  • The CTG inlet air cooling can be accomplished using evaporative coolers, foggers, or mechanical chillers.

While five turbines are up for approval under this Dec. 30 application, the company noted that there is room on the site for a sixth LM6000 CTG if needed in the future. Approximately 20 enclosures will house lithium-ion or flow batteries with a nominal capacity of 25 MW or 100 MWh.

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.