Coal-fired power plants in the Midcontinent Independent System Operator (MISO) region have maintained a stronger profitability edge over natural gas generators during the first four months of 2026, according to recent data from the U.S. Energy Information Administration (EIA). This advantage is measured by dark and spark spreads, which represent how much revenue power producers earn above their fuel costs. Coal’s dark spread averaged $28 per megawatt-hour (MWh), marking a 39% increase compared to the same period in 2025, while natural gas’s spark spread averaged $9/MWh, a 15% rise but still significantly below coal’s margin.
The trend of coal outperforming natural gas in profitability is not new. Since late 2024, coal’s dark spread has consistently exceeded the spark spread for natural gas within MISO. The gap between these two measures widened sharply during a severe winter event in January 2026 known as Winter Storm Fern. During this period, daily average power prices surged above $260/MWh despite electricity demand being 11% lower than typical pre-storm weekdays. This price spike was driven primarily by a dramatic rise in natural gas prices rather than increased consumption.
Natural gas prices increased more than twentyfold within a week during the storm, jumping from $25/MWh to $549/MWh. In contrast, coal prices remained stable due to the physical delivery system for coal requiring about a month’s lead time. This delay prevented coal prices from reacting immediately to sudden demand spikes caused by extreme cold weather, insulating coal-fired generators from the short-term volatility that natural gas generators faced.
Fuel price trends over the past two years have also contributed to coal’s growing profitability lead. Between 2024 and 2025, average electricity prices in MISO rose by 44%, but coal prices increased by only 3%. This allowed coal generators to see their dark spread grow by 111%, from $11/MWh to $23/MWh. Natural gas prices rose sharply by 63% during that time, limiting gains for gas generators and resulting in only an 18% increase in spark spread.
The structural differences between how coal and natural gas reach power plants are key to understanding these market dynamics. Natural gas generators typically rely on pipeline infrastructure allowing for near-instantaneous fuel delivery and pricing responses, making them vulnerable to rapid price changes during high demand periods such as cold snaps. Coal’s reliance on longer-term supply contracts and physical transportation delays offers more price stability but less flexibility.
EIA’s findings highlight important regional variations as well; trends observed in MISO differ from those in other markets like PJM. Overall, the data reveal that coal-fired generation has not only maintained but expanded its profitability advantage over natural gas generation through April 2026. This is driven by slower rising fuel costs for coal relative to electricity prices and rapid increases in natural gas costs that erode potential revenue gains for gas generators. Winter Storm Fern exemplified how these factors can sharply widen the profitability gap between the two fuels.
Looking ahead, these dynamics may influence investment decisions and operational strategies within the energy sector as stakeholders weigh fuel cost volatility against electricity market conditions.
