Gas & Power Generation

Natural gas is one of the key fuel inputs for electric power generation. New technology, particularly combined-cycle technology, made the natural gas power plant the generating system of choice in recent years in the U.S. In the Northeast region, natural gas represents about 50% of installed generating capacity. This page summarizes some of the key trends in the regional natural gas/electric power interconnection.

Gas Plant Advantages: Lower Emissions, Higher Efficiency

Power generation is one of the leading natural gas consuming sectors in the Northeast region. Shown here is a natural gas combined-cycle power plant in MA.

The comparative advantages of natural gas power generation include higher efficiency, lower heat rate, shorter construction lead times, and reduced air pollutant emissions compared to other fossil fuels.

The rise in natural gas use in power generation over the last two decades has been a key factor in achieving lower air emissions in the region, from sulfur dioxide to carbon dioxide. In June 2021, U.S. EIA noted that CO2 emissions from the U.S. electric power sector fell by 32% from 2005 to 2019. EIA observed: "Although both the increased use of renewables and the shift from coal-fired to natural gas-fired generation contributed to reductions in electric power sector CO2 emissions, the shift from coal to natural gas had a larger effect." EIA estimates that almost 65% of the decline in CO2 power sector emissions nationally over this time period is attributable to the shift from coal-fired to natural gas-fired electricity generation.

At the regional level, the same dynamic is in play. In New York State over the last 20+ years (from 2000-2022), NY ISO reports that emissions rates from the power sector dropped by 42% for CO2, and even more for NOx, and SO2.

PJM reports that between 2005 and 2022, CO2 emission rates fell 37% across its footprint, while nitrogen oxides dropped by 87% and sulfur dioxide by 95%.

ISO-NE reported in April 2023 that in the period between 2001 and 2021, generator emissions on its system declined by 99% for SO2, 80% for NOx, and 41% for CO2.

Natural gas generation also increases average plant efficiency. As noted by EIA in July 2020: "In recent decades, the U.S. electric power grid's fuel mix has shifted from mostly coal to a more diverse selection of fuels, including natural gas and renewable energy. In particular, the shift toward newer, more efficient natural gas-fired power plants with combined-cycle generators has resulted in an increase in the average efficiency of fossil fuel-fired electric power plants and in lower levels of overall conversion losses."

Gas Seen as Integral Part of Power Sector in Coming Decades

Natural gas is positioned to be among the leading fuels for electric power generation in the next decade (and beyond), along with renewables. Gas is also a key fuel input for new technology options like fuel cells, combined heat and power, and distributed generation.

Natural gas is also seen as the key "back-up fuel" to offset the variability and intermittency of some other resources. As the U.S. EIA noted in August 2020: "Natural gas is a key power generation resource because it has the flexibility to supply electricity at any time, including at times of peak demand. In contrast, some renewable energy technologies and nuclear power plants may be nondispatchable and not able to adjust their generation to meet load. For example, nuclear power plants may already be running at or near maximum capacity and may be unable to respond to shifts in load."

On the New England system in 2022, natural gas represented 52% of generation, and 45% of "net energy for load (NEL)" which factors in imports from neighboring regions (source: ISO-NE, January 2023).

Natural gas also plays a major role in the energy mix in New York State. In May 2023, the FERC noted that in NYISO, natural gas generation is expected to account for 54% of all generating capacity in summer 2023.

In its 2022 "Regional Transmission Expansion Plan," released in March 2023, PJM reports that natural gas represents 68% of total existing installed capacity in New Jersey (as of 12-31-22). For Pennsylvania, natural gas represents 49% of total existing installed capacity statewide. PJM notes that "PJM's RTEP process continues to manage an unprecedented capacity shift driven by federal and state public policy and broader fuel economics. This shift is characterized by:

  • New generating plants powered by Marcellus and Utica shale natural gas
  • New wind and solar generating units driven by federal and state renewable incentives
  • Generating plant deactivations
  • Market impacts introduced by demand response and energy efficiency program."

Natural Gas Impact on Electricity Prices

The increase in U.S. domestic production of natural gas engendered a much lower commodity price position for the fuel in recent years. This is good news for consumers of natural gas at all end-uses, including power plants.

The impact of natural gas prices on power markets is summarized in this text from ISO New England in April 2023:

    "Fuel is typically one of the major input costs in producing electricity. Natural gas is the predominant fuel in New England, used to generate 52% of the power produced in 2022 by New England's power plants, and natural gas-fired power plants usually set the price of wholesale electricity in the region. As a result, average wholesale electricity prices are closely linked to natural gas prices."

However, while the regional price can be quite low at certain months of the year, the delivery price of natural gas to Northeast markets can be quite volatile and high during strong-demand periods, especially in the winter.

The Northeast spot price volatility reflects delivery constraints during high-demand periods of intense cold (or even hot) weather. Natural gas utility customers are generally protected from the daily impact of spot prices, thanks to long-term contracts and storage resources held by local gas distribution companies. On the other hand, the power market in the region operates with high levels of interruptible gas capacity and is thus subject to spot market fluctuations, and that in turn impacts electricity customers.

In March 2017, the U.S. EIA observed: "Historically, both the Boston and New York natural gas markets have experienced winter price spikes because of pipeline constraints during periods of peak demand. Natural gas pipeline expansion projects that were completed in recent years may have reduced, but did not eliminate, sharp price increases with anticipated cold weather."

The Northeast region has experienced periods of high gas and power spot market price volatility over several recent winters, including the recent winter of 2022/23. In February 2021, U.S. EIA noted: "Natural gas prices in the United States tend to spike in winter months, particularly in New England, when natural gas supply becomes constrained during cold spells, resulting in correspondingly higher prices at the Algonquin Citygate near Boston, Massachusetts." In November 2023, the FERC noted: "Despite lower prices this winter, Algonquin Citygates is expected to have the highest futures prices for winter 2023-2024 of any U.S. hub - averaging $11.71/MMBtu, a decline of $7.70/MMBtu, or 40%, from last winter's average settled price. In New England, market exposure to high global LNG prices continues to contribute to elevated winter natural gas futures prices, as the New England regional natural gas market relies on imported LNG in the winter to meet peak natural gas demand, particularly during periods of pipeline capacity constraints. As a result, the New England region continues to compete for LNG volumes with Europe and Asia. Most of the year, the price at the Algonquin Citygates hub, located outside of Boston, is typically below the Henry Hub price. But, during winter months when natural gas demand in New England peaks above the region's natural gas pipeline import capacity, prices at the Algonquin Citygates hub routinely increase above Henry Hub prices."

It remains an ongoing challenge for the regional power market, New England in particular, relying as it does predominantly on interruptible natural gas capacity, due to its own power market design issues (see further discussion in section below).

Market Challenges

There are several unresolved power market issues that continue to challenge the market.
Photo credit: NPCC, 12-2022

Natural gas has become the central energy source for power generation in the Northeast region. In its May 2023 "Summer Energy Market Assessment," the FERC reports that ISO-NE and NY ISO are the most natural gas reliant RTO/ISOs [in the U.S.] with over 50% of their respective electricity generation output forecast tied to natural gas-fired power plants for the upcoming summer. Natural gas capacity as a percentage of all summer capacity will be highest nationwide in ISO-NE (57%), NYISO (54%), and ERCOT (48%). (Nationwide, natural gas represents 43% of the summer electric generating capacity mix across the United States.)

The increased reliance on natural gas provides some challenges for the electric grid operators. The states in the region want "clean energy" projects going forward but the arrival of offshore wind and/or long-range electric transmission is still a few years away. As the region continues to rely on natural gas for baseload generation, and for providing support for more intermittent resources like renewables, the lack of sufficient pipeline infrastructure to meet power sector needs remains an unresolved issue.

Most power generators in New England, for example, do not contract for firm gas pipeline capacity and instead rely on "if and as available gas" non-firm capacity, or, in some cases, capacity held by third parties. Pipeline capacity is added to meet the needs of gas customers who desire and are willing to execute contracts for such firm service. This reliance of the power system on non-firm gas transportation capacity for the majority of its gas units has proven challenging in several recent winters. The FERC noted in its pre-winter energy market assessment in November 2020:

"Because the [New England] region's supplying pipeline capacity is somewhat limited, consumers of natural gas tend to compete for supply when demand induced by cold weather soars. Due to the high winter demand and limited pipeline capacity, winter natural gas prices often peak during the coldest days of the year."

Fuel security, resource adequacy and grid resilience remain key topics for the entire U.S. power system, following strains on the electric grid in California in summer 2020, in Texas in February 2021, and in several areas of the country in December 2022 (from the Midwest to the Northeast to the South). Sufficient and reliable energy supplies and delivery capacity need to be ensured for every region.

Concern remains about winter month operational challenges to the Northeast power grids. In New England, for example, many generating resources have retired in recent years (such as nuclear, coal, and oil), only increasing the power system reliance on natural gas; but that reliance is itself somewhat tenuous, as most of the power generators' natural gas supply arrangements are on a "non-firm" basis.

The importance of reliability and the value of natural gas generation was addressed in a June 2021 blog article by the NY ISO. Among the ISO's observations: "As the state reviews a potential moratorium on any new or repowered gas generation, we have to ask the question of how to maintain reliability during the iterative, multi-step process to a carbon-free grid as contemplated by the CAC [Climate Action Council]. At the NYISO, we've performed studies to examine how a zero-emissions grid will perform, modeling a number of scenarios in which renewable resources (such as solar and wind) and non-emitting resources (such as energy storage) exclusively supply the grid. We've presented some of these studies to the CAC in order to help plan for the 2040 grid of the future. These studies show that fossil fuel-powered resources will continue to be needed on the road to 2040 to offset this intermittency until new, cleaner technologies can provide the responsiveness now fulfilled primarily by natural gas generation. Limiting options at the start of the transition could actually stifle progress toward our climate goals and produce higher emissions along the way."

In an op-ed in February 2022 in "Commonwealth Magazine," the CEO of ISO-NE expressed some of the same operational and reliability concerns as those expressed by NY ISO in the summer of 2021. Gordon van Welie of ISO-NE stated: "In the interim, we cannot escape the reality that until more clean energy resources are built, and until we have a robust, long duration source of clean balancing energy, the region will remain reliant on natural gas and, to a lesser extent, oil-fired generation to both produce the power it needs and to balance supply and demand during periods when renewables cannot produce electricity."

In February 2023, PJM released a report entitled "Energy Transition in PJM: Resource Retirements, Replacements and Risks," which provides some timely analysis about the challenges of the energy transition. The report explores the pace of resource retirements and replacements through 2030 and highlights potential reliability risks to meeting growing electricity demand. The report notes that "PJM's interconnection queue is composed primarily of intermittent and limited-duration resources. Given the operating characteristics of these resources, we need multiple megawatts of these resources to replace 1 MW of thermal generation." The report further notes the following: "Overall, the amount of generation retirements appears to be more certain than the timely arrival of replacement generation resources and demand response, given that the quantity of retirements is codified in various policy objectives, while the impacts to the pace of new entry of the Inflation Reduction Act, post-pandemic supply chain issues, and other externalities are still not fully understood. Should these trends continue, PJM could face decreasing reserve margins for the first time in its history."

The discussion continues this year and beyond as the Northeast region's power markets evolve to reflect the changing policy and regulatory environment, while managing near- and mid-term system operational issues.

Electric & Gas Industry Coordination

The natural gas and electric system operators in the Northeast continue to increase communications and coordination. NGA and ISO New England, for instance, jointly administer an Electric & Gas Operations Committee (EGOC) to increase understanding and information exchanges (on publicly-available information). The EGOC includes the NY ISO and PJM as well as other stakeholders.

NGA also updates the electric grid operators regularly regarding the coordinating work of NGA's Gas Supply Task Force.

With natural gas remaining a significant fuel going forward for electric generation, coordination efforts such as these - both regionally and nationally - are to be encouraged.

For Further Information


Northeast interstate pipelines' electronic bulletin boards (EBBs)

ISO New England

New York ISO


Northeast Power Coordinating Council (NPCC)

North American Electric Reliability Corporation (NERC)

Interstate Natural Gas Association of America (INGAA)

North American Energy Standards Board (NAESB)