Hill Top Energy Centre

The Hill Top Energy Centre is a 620MW natural gas-fired, combined-cycle power project under construction in Greene County, Pennsylvania, US.

Hill Top Energy Centre (HTEC) will be the owner and operator of the facility which is being developed with an estimated investment of approximately £559m ($726m).

The project is being jointly financed and sponsored through a partnership between Ares Management, Menora Mivtachim Insurance, and Ardian Infrastructure (formerly AXA Private Equity). Ardian Infrastructure became a funding partner for the project by acquiring a 41.9% stake in HTEC in July 2019.

While the construction works were started in March 2019, the Hill Top Energy Centre facility is slated to begin operations by June 2021.

Location and site details

The Hill Top Energy Centre combined-cycle power project is located approximately 1.6km north of Nemacolin town in Cumberland township, Greene County, Pennsylvania, US.

The project is located on an approximately 41.7-acre brownfield site originally owned by the LTV coal mining company.

Hill Top Energy Centre plant make-up

The Hill Top Energy Centre will comprise a one-on-one (1×1), single-shaft combined-cycle power block equipped with a 7HA.02 gas turbine, a steam turbine-generator set, and a heat recovery steam generator (HRSG) supplied by GE.

The HRSG assembly will be fitted with a selective catalytic reduction (SCR) system to minimise nitrogen oxide (NOx) emissions, and oxidation catalysts to control carbon monoxide (CO) and volatile organic compound (VOC) emissions from the combustion turbine (CT) and duct burners.

The project also involves the construction of a 2-mile raw water intake pipeline and a pump facility on the Monongahela River, a 4.9-mile gas pipeline, and approximately 3.4acres of water intake facility on site.

The other components in the project include a combustion turbine inlet evaporative cooler, evaporative cooling tower system, and sulphur hexafluoride (SF₆) emissions circuit breakers equipped with low-pressure alarms for leak detection.

Infrastructure facilities

The other infrastructure facilities for the project include a 2,000KW emergency diesel generator along with a 422 horsepower (hp) emergency diesel fire water pump. While the emergency diesel generator will facilitate maintenance of plant loads during power outages or switchyards maintenance, the diesel-fired pump will be used during emergency fire incidents as well as for routine operations and testing.

The plant will also house a 42 MMBtu/hr natural gas-fired auxiliary boiler to provide high-temperature steam during start-ups and shutdowns. A 6.4 MMBtu/hr flue gas heater will be provided to condition the natural gas, preventing it from condensation.

The miscellaneous tanks at the site will include a diesel fuel tank, lubricating oil tank, and aqueous ammonia storage tanks.

Power evacuation

The electricity generated by the Hill Top Energy Centre will be evacuated through a 4.83km 500kV power transmission line connecting the Pennsylvania-Jersey-Maryland (PJM) transmission network.

Contractors involved

Kiewit Constructions was engaged as the engineering, procurement, and construction (EPC) contractor for the project while General Electric (GE) was selected for the supply, installation, along with a multi-year services agreement for the turbines and generators of the facility in May 2019.

NAES Corporation was contracted for the operation and maintenance services of the combined-cycle power plant.

Flenco Fluid System was subcontracted by General Electric for the supply of auxiliary systems for the project, while E3 Consulting was engaged to provide the construction monitoring services for the Hill Top Energy project.

Environmental Consulting and Technology (ECT) was hired to render support services related to environmental and air quality permissions. The scope also included archaeological surveys along with coordination with reviewing agencies for approvals.