October 2021, Vol. 248, No. 10
Features
Natural Gas-Fired Generators Used More in PJM Interconnection
Special to P&GJ
The rapid development of shale gas resources in Pennsylvania, Ohio and West Virginia has contributed to sustained low natural gas prices, and it has encouraged the construction of natural gas-fired power plants.
About one-third of the new natural gas-fired generating capacity built in the United States since 2010 is located in the PJM Interconnection (PJM), the grid operator for all or parts of 13 states in the mid-Atlantic region, including Pennsylvania, Ohio and West Virginia.
In 2020, the utilization rate, called capacity factor, of natural gas-fired combined-cycle (NGCC) units built from 2010 to 2020 in PJM was 71%, which was higher than that of older units in the region, according to the U.S. Energy Information Administration (EIA).
Two factors affect the utilization of a combined-cycle natural gas generator: the efficiency of the generator and the delivered cost of natural gas. Newer NGCC generators use more efficient turbine technology and are generally larger than older units.
Although all NGCC generators tend to increase or decrease use in response to changes in the price of natural gas, older units tend not to be used when natural gas prices rise, because they are less efficient and more expensive to run than newer technology units.
EIA separates combined-cycle natural gas turbines in PJM into three groups, which reflect the turbine technologies available at the time they were built:
- Units built from 1990 to 1999 – B-, D-, and E-class gas turbines (GT) with 80 MW to 110 MW capacity and average heat rates greater than 8,000 Btu per kilowatt hour (Btu/kWh) in combined-cycle mode
- Units built from 2000 to 2009 – First-generation F-class GTs with 160 MW to 190 MW capacity and average heat rates of 7,300 Btu/kWh in combined-cycle mode
- Units built from 2010 to 2020 – Next-generation F-class GTs with 200 MW to 225 MW capacity and average heat rates of 7,000 Btu/kWh in combined-cycle mode, first-generation advanced H- and J-class GTs with 265 MW to 340 MW capacity and 6,700 Btu/kWh heat rates in combined-cycle mode
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