Dominion seeks gas system upgrades to support Mattawoman power project

Dominion Cove Point LNG LP (DCP) filed Nov. 15 for authorization from the Federal Energy Regulatory Commission to construct, install, own, operate, and maintain certain facilities located in Charles County, Maryland, and Loudoun and Fairfax counties, Virginia, which are needed in part to serve the new Mattawoman power plant in Maryland.

DCP is a unit of Dominion Resources (NYSE: D). This is called the Eastern Market Access Project. The project would include incremental compression and appurtenant facilities along DCP’s existing transmission pipeline. No new pipeline right-of-way (ROW) will be required.

The project will consist of:

Charles Station (Charles County, Maryland)

  • Construct a new compressor station with approximately 24,370 horsepower (hp) (Solar Taurus 701 compressor unit 11,150 hp and Solar Mars 902 compressor unit 13,220 hp) of natural gas compression.
  • Install exhaust silencers/Selective Catalytic Reduction (SCR) systems and oxidation catalysts on the two units.
  • Install gas coolers, suction filter/separators, blowdown separator/silencers for the two units and station piping.
  • Install one hot water boiler, natural gas auxiliary generator, station ancillary equipment, supporting station tanks, and yard piping.
  • Construct one compressor building, one auxiliary building, and one drum storage building.

WGL Interconnect (Charles County, Maryland)

  • Install two new taps (one on TL-522 pipeline and one on TL-532 pipeline) for customer delivery.

Loudoun Compressor Station (Loudoun County, Virginia)

  • Install one 7,000 hp electric reciprocating compression unit in a new compressor building at the existing compressor station.
  • Install one discharge gas cooler and ancillary equipment and one blowdown separator/silencer for the new compression unit.
  • Install suction filter/separator(s).
  • Construct a Power Distribution Center (PDC) building, along with new switchgear (SWGR) and electrical infrastructure.
  • Replace the compression cylinders of the three existing reciprocating engines.
  • Replace the three existing gas coolers.
  • Increase main gas discharge pipe to 30-inch diameter.

Loudoun Metering and Regulating (M&R) Station (Loudoun County, Virginia)

  • Construct a new meter building to enclose existing equipment.

Pleasant Valley Compressor Station (Fairfax County, Virginia)

  • Re-wheel compressor on one existing 17,400 hp electric unit at the existing compressor station.
  • Upgrade two existing gas coolers.

The purpose of the project is to provide 294,000 dekatherms per day (Dt/d) of natural gas and firm transportation services for a local distribution company (LDC) and to fuel a power generation facility to help meet the need of increasing demand for natural gas in the Mid-Atlantic region. The project customers include Washington Gas Light Co. (WGL) and Mattawoman Energy LLC. WGL is a LDC that provides natural gas service to more than 1.1 million customers in Washington, D.C, Maryland, and Virginia.

The application noted: “Mattawoman is planning to build an 990-megawatt combined-cycle gas-fired generating station, the Mattawoman Energy Center, in Prince George’s County, Maryland. Today, DCP is the only interstate natural gas pipeline system within proximity to the Mattawoman Energy Center. Therefore, Mattawoman is contracting with DCP as the main source of natural gas for the generating station. The Mattawoman Energy Center would provide power to the Maryland power grid and supply the power needs of up to 990,000 homes.”

Notable is that PJM Interconnection on Nov. 14 filed with FERC an executed, revised interconnection service agreement (ISA) with Mattawoman Energy LLC and interconnecting transmission owner Potomac Electric Power Co. This new Mattawoman ISA supersedes an ISA filed with and accepted by the commission last year.

The Mattawoman ISA facilitates the interconnection to the PJM system of 1,038.1 MW (Maximum Facility Output) at the gas-fired, combined-cycle Mattawoman Energy Facility to be located on Brandywine Road in Prince George’s County, Maryland.  The Mattawoman ISA modifies the Maximum Facility Output to specify that there is a 144.1 MW increase in the Maximum Facility Output, for a total of 1,038.1 MW. Under the revised ISA, by April 1, 2019, Mattawoman Energy must demonstrate commercial operation of all generating units.

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.