Garrison Energy Center is a 309MW combined-cycle gas-fired electric generating facility located adjacent to the existing Dover SUN Park in the Garrison Oak Technical Park in Dover, Delaware. The greenfield project, built on a 37-acre land leased from the city of Dover, is expected to provide power to 250,000 homes.
Calpine Garrison, a subsidiary of Delaware’s biggest energy producer Calpine Corporation, owns the facility. The project is the result of an initiative by Calpine to reduce carbon pollution by limiting the use of coal at its Delaware facilities.
The ground breaking ceremony for the project was held in June 2013, and operations began in June 2015. The energy centre generated more than 250 local construction jobs, in addition to 16 permanent jobs, and has reduced electricity costs for customers.
An additional 309MW of generation capacity is proposed to be added to the facility in phase II. The feasibility, system impact and facilities studies for phase II have been completed by PJM.
Garrison Energy Center make-up
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 to supply its governmental customers.
The Garrison energy center is equipped with a General Electric 7FA combustion turbine, a heat recovery steam generator, a steam turbine, an 86,000gal/min cooling water tower and a 1.4 million gallon storage tank for ultra-low sulphur diesel (ULSD), which is the turbine’s back-up fuel in the event of insufficient natural gas.
The natural gas-fired combustion turbine generates 193MW of energy, whereas 116MW is generated from the heat recovery steam generator (HRSG). Air pollution control technologies complying with the best available control technology (BACT) and the lowest achievable emissions rate (LAER) requirements established by the federal regulations under the clean air act are used at the plant.
Natural gas supply for the Garrison Energy Center
Natural gas is supplied to the Garrison Energy Center under a precedent agreement between Eastern Shore Natural Gas (ESNG), a subsidiary of Chesapeake Utilities Corporation, and Calpine Energy Services. ESNG transports 45,000dt/d of natural gas via the White Oak lateral gas pipeline, by connecting its existing mainline near Cheswold to the Garrison Energy Center.
ESNG completed the White Oak lateral gas pipeline project in October 2014. The new 5.5mi (8.8km)-long and 16-inch diameter pipeline was constructed with the help of a $2.5m grant from the city’s New Jobs Infrastructure Fund.
Natural gas is transported using ESNG’s new off-peak transportation (OPT) rate schedule. The new OPT provision, approved by Federal Energy Regulatory Commission (FERC) in September 2014, will generate $5.8m a year for ESNG from natural gas transportation to Calpine.
The OPT service enables a customer to save money by waiving service for 90 days a year. Calpine’s Garrison Energy Center has dual fuel capability to alleviate the effects of any gas interruption during a 90 day period.
Transmission of power from the Garrison Energy Center
The plant is connected to Delmarva Power and Light transmission system at the Cartanza 230kV substation. The generated power is sold to the PJM wholesale regional grid.
Delmarva Power, the electricity and natural gas provider in Delaware region, and PJM, operator of the regional electricity grid, conducted the feasibility study for the project.
Calpine Garrison awarded a contract to construct the Garrison Energy Center to Kvaerner North American Construction, a subsidiary of Kvaerner, and its joint venture (JV) partner Parsons Brinckerhoff, in December 2012.
The engineering, procurement and construction (EPC) contract was valued between $100m and $120m. The JV was led by Kvaerner, who was responsible for the construction of the facility, while Parsons Brinckerhoff was responsible for the design, procurement of the balance of plant equipment and the commissioning, working in collaboration with Matrix North American Construction, a subsidiary of Matrix Service Company.
Alstom Grid was subcontracted by Parsons Brinckerhoff for the engineering, procurement and construction. A team of civil and structural engineers from NEI partnered with Alstom Grid to provide designs for the 230kV transmission line, two 230kV substations and ancillary facilities.