AltaGas seeks approval for 100-MW Pomona repower project

AltaGas Pomona Energy applied March 21 at the California Energy Commission for approval of the Pomona Repower Project (PRP), which is a natural-gas-fired, simple-cycle, water-cooled facility with a nominal net output of 100 MW that will replace the San Gabriel Facility, an existing and operating power plant in Pomona, California.

PRP will be located on a 2-acre parcel in the City of Pomona in Los Angeles County and located in the Pomona Valley, directly 28 miles east of the city of Los Angeles.

PRP will be powered by one General Electric LMS100 gas turbine. The balance of plant equipment will include natural gas compressors, water treatment facilities, emergency services, administration/maintenance building and a cooling tower to provide gas turbine compressor inter-stage and auxiliary cooling. PRP will include the removal of the existing LM5000 gas turbine currently in operation.

Demolition of the existing facility, expected to take three months and to occur in the first half of 2017, will provide the space required for the construction of PRP. Project construction is expected to take approximately 16 months (3rd Quarter 2017 to 4th Quarter 2018). Commissioning is scheduled to start in the fourth quarter of 2018 and be completed by the first quarter of 2019.

PRP will use existing supply and discharge lines including natural gas, potable and recycled water supply, process wastewater, and sanitary wastewater. The project will use recycled water from the Pomona Water Reclamation Plant for cooling and appropriate process water uses.

The LMS100 will use the existing 66-kV Simpson transmission line connected to Southern California Edison’s 66-kV Ganesha-Simpson transmission line. The existing poles will be upgraded with new conductors to account for the additional power generated by the LMS100.

PRP has been designed using commercially proven technology equipped with monitoring, protection, and safety systems to provide safe and reliable operation over a 30-year operating life. It will consist of a single simple-cycle gas turbine power block, being able to be controlled remotely in the PRP control room. The PRP power block will use existing utilities and include the following principal design elements:

  • One General Electric LMS100PA CTG with a nominal net rating of 100 MW. The CTG will be equipped with evaporative coolers on the inlet air system, compressor inter-stage cooling, and water injection to control NOx;
  • An increase in the height of the exhaust stack from 75 to 90 feet tall;
  • One multi fan, induced draft cooling tower;
  • Two fuel gas compressors;
  • One 10,000-gallon ammonia storage tank containing 19 percent aqueous ammonia (same size as existing tank);
  • One demineralized water treatment system;
  • Approximately 0.2 mile of reconductored 66-kV transmission line (generation tie-line, or gen-tie line) connecting to the Ganesha-Simpson transmission line;
  • Existing natural gas pipeline;
  • Existing potable and recycled water supply lines; and
  • Existing stormwater, sanitary sewer, and wastewater lines.

PRP is bounded by industrial warehouse structures to the north, east and west. A large rectangular warehouse structure adjoins PRP to the south, bordered by rail lines.

The project site will include two 200,000-gallon water storage tanks located on the north side of the site, one 10,000-gallon, 19 percent aqueous ammonia storage tank with an unloading area located on the east side of the site, a water treatment area, a storage warehouse/admin building and a gas compressor enclosure all located on the west site of the site.

Natural gas is currently available onsite. A new gas compressor/pressure control station, and gas scrubber/filtering equipment will be constructed by the project owner as part of the project. Natural gas will then be distributed onsite to the combustion turbine.

Construction of PRP will be coordinated with the demolition of the existing San Gabriel Facility so that site impacts are minimized. Due to space limitations at the site, site demolition will be completed prior to the start of construction.

Auxiliary equipment includes: cooling tower for heat load rejection, SCR systems for NOx emissions control, oxidation catalyst equipment to control carbon monoxide (CO) and VOC emissions, and a fuel gas compressor and regulating station.

The use of the evaporative coolers is not intended as power augmentation, but rather will be employed to mitigate CTG degradation (ambient and mechanical) to maintain the facility at or near the nominal generating capacity. The predicted net electrical output of PRP under these conditions is approximately 97.8 MW at a heat rate of approximately 8,244 British thermal units per kilowatt hour (Btu/kWh) on a lower heating value (LHV) basis. This corresponds with a thermal efficiency of approximately 41.4 percent on a LHV basis.

Some of the applicant’s basic project objectives are:

  • To safely and economically construct, operate and maintain an efficient, reliable, and environmentally-sound nominal 100-MW (net), natural-gas-fired, simple-cycle generating facility to replace the aging 44.5 MW San Gabriel Facility.
  • Develop a nominal 100 MW (net) project that provides efficient operational flexibility with rapid-start and steep ramping capability to allow for the efficient integration of renewable energy sources into the California electrical grid.
  • Reuse existing electrical, water, wastewater, and natural gas infrastructure and land to minimize terrestrial resource and environmental justice impacts by developing on a brownfield site.
  • Serve Southern California energy demand with efficient and competitively priced electrical generation.
  • Site the project to serve the eastern Los Angeles Basin load center without constructing new transmission facilities.
  • Assist the state in developing increased local generation projects, thus reducing dependence on imported power.
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.