Natural gas-fired combined-cycle power plant
Charles County, Maryland
Marubeni (50%), Toyota Tsusho (25%), CPV (25%)
Start of Commercial Operations
EthosEnergy Power Plant Services
Competitive Power Ventures (CPV) St Charles Energy Center is a natural gas-fired combined-cycle power plant being developed in Waldorf, Charles County, Maryland. It was originally planned to have an installed capacity of 640MW, which was later increased to 725MW. The groundbreaking ceremony for the project occurred in December 2014, while commercial operations are expected to begin in 2017.
CPV owns 25% stake in the project, while partners Marubeni and Toyota Tsusho have 50% and 25%, respectively.
The project is expected to create up to 400 jobs during construction as well as 24 permanent jobs during operation. It will generate enough power for approximately 700,000 households and be one of the biggest taxpayers in the County. EthosEnergy Power Plant Services will be the operator of the plant.
Astoria Energy LLC was authorised by the New York Power Authority (NYPA) in April 2008 to build a second natural gas-fuelled plant in Queens.
The project is being developed in a 76-acre greenfield site in the Piney Reach Industrial Park. The site was purchased from the St Charles Companies for $13m in September 2014.
The site is located close to existing gas and electrical transmission infrastructure, eliminating the need to construct new transmission towers or power lines, which provides cost advantages for the project.
CPV St Charles plant make-up
The plant will consist of two GE 7F.05 gas turbines of 225MW each, a GE D402 steam turbine generator in a ‘2×1’ configuration and two duct-fired, triple-pressure reheat heat recovery steam generators. GE will provide the equipment under the FlexEfficiency 60 combined-cycle engineered equipment package supply contract, worth $260m. The contractual scope also includes a 16-year services agreement.
Reclaimed water from the Mattawoman Wastewater Treatment Plant (MWWTP) will be used for wet cooling at the plant. The wastewater will be discharged into the same water treatment plant.
Financing for the power plant
The CPV St Charles project achieved financial closure in August 2014. It is being financed by GE Energy Financial Services and 14 other lenders. GE Energy Financial Services acted as the primary lead arranger and book runner to anchor $550m senior secured credit facilities for the project.
Power grid and transmission
CPV St Charles is planned to be interconnected to the regional electric transmission system using the existing 230kV overhead transmission lines owned by Potomac Electric Power Company (Pepco).
The plant site is located adjacent to the Pepco’s right-of-way (ROW) containing four 230kV circuits. CPV St Charles will be interconnected to two of these four overhead transmission lines. The two lines will be extended to connect to the new power generating station.
The generated power will be delivered through the regional transmission organisation, PJM.
SNC-Lavalin Group won the engineering, balance of plant procurement and construction (EPC) contract for the project. Natural gas will be supplied by Dominion from either its Cove Point liquefied natural gas (LNG) terminal or existing gas transmission pipeline.
Local environmental impact
Use of grey water from the MWWTP for wet cooling will substantially reduce strain on the local water sources. It would also result in lesser nitrate discharges from the MWWTP to the Potomac River (and Chesapeake Bay).
The plant will release 98% lesser sulphur dioxide (SO₂) and nitrogen oxide (NOx) emissions compared to conventional coal-fired and oil-fired power plants of equivalent capacity.