Dominion Cove Point LNG LP plans to build a 130-MW (nameplate), gas-fired power plant at its Cove Point, Md., liquefied natural gas (LNG) import-export facility, with the power plant to only supply power for within-the-fence needs at the LNG facility.
The company, a unit of Dominion Resources (NYSE: D), applied April 1 at the Maryland Public Service Commission for a Certificate of Public Convenience and Necessity on the power project, to be located in Calvert County. The generating station will be constructed entirely on the site of the existing LNG terminal on land now owned by Dominion Cove Point, and should have minimal environmental or land use impacts in Maryland, the company told the commission.
Dominion Cove Point owns and operates a LNG import terminal and an interstate pipeline that extends approximately 88 miles from the LNG terminal on the Chesapeake Bay to various interconnections with the interstate pipeline grid. The construction and operation of these existing facilities have been authorized by the FERC under the Natural Gas Act, including the existing electric generating capacity at the LNG terminal, and the Maryland commission has previously approved and/or exempted the construction of generating stations at the LNG terminal.
Contemporaneously with the filing of this application in Maryland, Dominion Cove Point requested FERC authorization to construct and operate new facilities – and expand existing facilities – as part of the Liquefaction Project, which includes the additional electric generating facilities that are the subject of this application.
In the FERC application, Dominion Cove Point has requested federal approval of the Liquefaction Project by Feb. 1, 2014, so that construction of the liquefaction facilities can begin in the first quarter of 2014. This approval date is critical to ensure that commercial operations will meet a targeted in-service date of June 2017.
LNG terminal has been in and out of business over the years
Dominion Cove Point owns and operates a federally-approved LNG terminal located on the western shore of the Chesapeake Bay near Cove Point in Lusby, Calvert County. The LNG terminal was initially authorized in 1972 by FERC’s predecessor agency, the Federal Power Commission, as part of a project to import LNG and transport natural gas to U.S. markets. The LNG terminal received shipborne LNG imports between 1978 and 1980, when the shipments ceased. In 2001, its previous owner sought and obtained authorization from the FERC to recommence LNG imports by constructing new facilities, and by reactivating and operating existing facilities.
The proposed new liquefaction facilities, combined with existing facilities, will allow for the bi-directional service of receiving and gasifying imported LNG from LNG vessels, and liquefaction of natural gas for loading onto LNG vessels for export.
The new liquefaction facilities will consist of one LNG train expected to have a nameplate capacity of up to 5.75 million metric tons per annum (mtpa) of LNG; new natural gas-fired turbines to mechanically drive the main refrigerant compressors; the generation of additional power on-site to meet the power demands of the Liquefaction Project; and equipment to remove impurities from the gas stream. Also, the Liquefaction Project will involve off-site temporary construction areas, as well as installation of additional compression in Virginia on the Cove Point Pipeline which is required to deliver the inlet gas to the LNG terminal.
“In order to provide additional power needed for the Liquefaction Project, Dominion Cove Point is requesting authorization to construct and operate a generating station with a 130 MW name-plate capacity comprised of two highly efficient 65 MW steam turbine generating units,” the company said. “These generating units will operate in combined cycle mode with steam generated from the waste heat from gas turbines used to mechanically drive the compressors used for the liquefaction process. These steam turbines will be located at the LNG terminal and used to provide the additional power needed for the Liquefaction Project. All of the power from these units will be consumed on-site. The addition of these facilities at the LNG terminal will bring the total on-site name-plate generating capacity to 210.9 MW, which allows the facility to serve existing and new customers, and allows for sufficient backup to provide for the facility’s necessary reliability.”
To ensure that no power leaves the LNG terminal, Dominion Cove Point will continue to maintain the protection equipment that prevents electricity produced at the LNG terminal from flowing to the Southern Maryland Electric Cooperative (SMECO), which is the electric service provider for the area.
New plant to based around General Electric turbines
The new generating station would be comprised of two steam turbines with nameplate ratings of 65 MW each. There will be two auxiliary boilers and two heat recovery steam generators (HRSGs) supplying steam to the turbines. The HSRGs will recover heat from the two GE Frame 7 natural gas-fired turbines, which drive the two refrigeration compressor strings along with helper motors. Both the auxiliary boilers and the HRSGs will have Selective Catalytic Reduction (SCR) systems and CO catalyst with Continuous Emissions Monitoring (CEM).
Although the nameplate ratings of the two steam turbines are a total of 130 MW, the condensing capability of the design will limit their output to about 90 MW. Although current load conditions indicate that approximately 80 MW of power will be needed for the Liquefaction Project under normal conditions, there needs to be a high level of reliability, so the steam turbines are being sized to provide full service under a variety of conditions including loss of a single steam turbine, and a variety of ambient and upset conditions.
Dominion has made various supplemental filings with the PSC since the application, including a May 15 report that contains further details on air impacts of the power project. Various parties, including the Sierra Club and the Chesapeake Climate Action Network, have intervened in the case, which was still ongoing as of May 23.