Invenergy's Allegheny Energy Center
Allegheny County consistently fails to meet federal health-based standards for air pollution. Invenergy wants to build the Allegheny Energy Center - a large methane gas-fired power plant - in Elizabeth Township in the southeastern corner of Allegheny County. Positioned close to the county line, the proposed plant would not only increase pollution for the local community within the county, but also release pollution into environmental justice areas on the other side of the county line, outside the jurisdiction of the Allegheny County Health Department (ACHD). The power plant would emit air pollutants known to be harmful to human health as well as greenhouse gases that worsen climate change.
GIS map of Invenergy's proposed Allegheny Energy Center and surrounding region.
Invenergy's Allegheny Energy Center Project Overview
Invenergy is proposing to build the Allegheny Energy Center (AEC), a 639 megawatt methane gas-fired combined cycle power plant. Energy that is generated will be fed directly into the PJM energy grid mix and will not have any local benefits. Invenergy estimates that it will employ 24-30 workers.
AEC plans to use low sulfur pipeline-quality methane. The facility will store 20,000-gallons of aqueous ammonia in storage tanks onsite.
The facility is a major source of nitrogen oxides (NOX), carbon monoxide (CO), and volatile organic compounds (VOCs) emissions and a minor source of particulate matter 10 (PM10), particulate matter 2.5 (PM2.5), sulfur dioxide (SO2), and hazardous air pollutants (HAPs). The facility will need permit approvals from the PA Department of Environmental Protection (PaDEP) and Allegheny County Health Department (ACHD). ACHD has submitted applications, while PaDEP has yet to review any applications so far.
Plume Map via Plume Pittsburgh
Air Pollution from Major Sources in Allegheny County
Invenergy is a multinational company that specializes in power generation based in Chicago, IL. The company develops, builds, owns and operates power generation and energy storage projects in the Americas, Europe and Asia. These projects include wind and solar farms, natural gas power generation and long-term energy storage facilities.
Invenergy's Allegheny Energy Center Project Timeline (2016 - Present)
In 2016, Invenergy proposed the Allegheny Energy Center Power Plant at the Buena Vista site (yellow marker).
However this special zoning exception was denied by the local zoning hearing board after community pressure mounted, and Invenergy had to relocate the facility to another location (orange boundaries).
Google Maps Image of AEC moving from Buena Vista site (yellow marker) New site (orange). Image provided by EIP/MWA.
Public Meeting. Image Courtesy of EIP/MWA.
In 2017, Invenergy proposed rezoning a 25 acre parcel at the current site.
The application was denied after concerns were raised by the Allegheny County Planning Commission.
However, In 2018, Invenergy proposed rezoning 147 acre parcel, and the application was approved by the zoning board despite strong public opposition.
Google Maps Image of new AEC site. New site is 5 miles from Tenaska power plant. Image provided by EIP/MWA.
The AEC is a major source of nitrogen oxides (NOX), carbon monoxide (CO), and volatile organic compounds (VOCs) emissions and a minor source of particulate matter 10 (PM10), particulate matter 2.5 (PM2.5), sulfur dioxide (SO2), and hazardous air pollutants (HAPs).
Despite listening to more than three hours of public comment in opposition to the proposal, the Elizabeth Township Commissioners voted 4-3 to pass a controversial ordinance and zoning change that would allow construction of a power plant in a rural and residential neighborhood.
What is a Combined-Cycle Power Plant?
Information taken from Allegheny County Health Department Public Presentation in Elizabeth Township, May 2021
1. Gas turbine burns fuel
The gas turbine compresses air and mixes it with fuel that is heated to a very high temperature. The hot air-fuel mixture moves through the gas turbine blades, making them spin.
The fast-spinning turbine drives a generator that converts a portion of the spinning energy into electricity.
2. Heat recovery system captures exhaust:
A heat recovery steam generator (HRSG) captures exhaust heat from the gas turbine that would otherwise escape through the exhaust stack.
The HRSG creates steam from the gas turbine exhaust heat and delivers it to the steam turbine.
3. Steam turbine delivers additional electricity:
The steam turbine sends its energy to the generator drive shaft, where it is converted into additional electricity.
Combined-cycle power plant diagram. Image taken from Bridgestone Associations Limited. https://brdgstn.com/combined-cycle/