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 2000-2021), NY ISO reports that emissions rates from the power sector dropped by 46% for CO2, ~92% for NOx, and 99% for SO2.

Chart: NY ISO, June 2022

PJM reports that between 2005 and 2021, CO2 emission rates fell 35% across its footprint, while nitrogen oxides dropped by 85% and sulfur dioxide by 94%.

ISO-NE reported in April 2022 that in the period between 2001 and 2020, generator emissions on its system declined by 99% for SO2, 78% for NOx, and 42% 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."

Natural gas plays a major role in the energy mix in New York State. In May 2022, the FERC noted that in NYISO, natural gas capacity will account for 59% of all summer capacity in summer 2022.

In its 2021 state profiles released in March 2022, PJM reports that natural gas represents 66.5% of total installed capacity in New Jersey, and 16.5% of new interconnection requests in the state (as of 12-31-21). For Pennsylvania, natural gas represents 44.8% of total installed capacity statewide, and 13.8% of new interconnection requests. PJM notes in its "2021 Regional Transmission Expansion Plan," released in March 2022, that "Aging infrastructure, grid resilience, a shifting generation mix and more localized reliability needs are now more frequently driving new system enhancements...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

Chart: ISO-NE, May 2021
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 well in these two quotes from ISO New England:

    "Wholesale electricity prices rise and fall in real time based primarily on fuel prices (which are generally the biggest cost for power plants), demand for power, and transmission system conditions."

    "With about 50% of the region's generators able to run on natural gas, the price of this single fuel sets the energy market price most of the time. The high efficiency of natural-gas-fired generators and the generally low cost of nearby domestic shale gas (which emerged as a resource in 2008) are largely responsible for the significant decrease in the average annual price of New England's wholesale electricity over the past 10 years. After plummeting almost 50% a decade ago, average wholesale energy prices have remained consistently low since then. Lower wholesale prices translate into lower power-supply charges for consumers."

In its May 2021 "Power Trends" report, NY ISO noted:
    "Wholesale electricity prices are directly influenced by the cost of the fuels used to produce electricity. In New York, the cost of natural gas and the price of electricity are closely correlated because, based on the current resource fleet, gas-fired generation often establishes the clearing price for electricity in the NYISO's wholesale electricity market. Average annual wholesale energy prices in the NYISO's market reached a record low of $25.70/MWh in 2020."

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 in the U.S. over several recent winters - in 2013/14, 2014/15, 2017/18, and 2021/22. 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 its December 2022 "Short-Term Energy Outlook," looking ahead to the 2022/23 winter, EIA stated: "The highest forecasted electricity prices for this winter are in ISO New England, where we expect on-peak wholesale power prices will average more than $200 per megawatthour in January, up 35% from January 2022. Capacity constraints on pipelines delivering natural gas into New England make it likely that wholesale electricity prices will be set by relatively expensive imported LNG or fuel oil."

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 2022 "Summer Energy Market Assessment," the FERC reported that "NYISO and ISO-NE are the most natural gas dependent RTO/ISOs [in the U.S.] with over 50% of their respective electricity generation output forecast tied to natural gas-fired power plants this summer...Natural gas capacity as a percentage of all summer capacity will be highest in NYISO (59%), ISO-NE (50%), and ERCOT (47%)."

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, including the winter of 2017/18. 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 the tenuousness of parts of the Northeast power grid during the winter months, particularly in downstate New York State and in New England. 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 wrote in February: "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."

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)