A US gas-fired power plant burned 7.78 million Btu of natural gas, about 7.5 thousand cubic feet, for every megawatt-hour it generated in 2025, on EIA's average heat rate of 7,781 Btu per kilowatt-hour. A combined cycle plant needed 7.54 MMBtu per MWh; a simple-cycle turbine needed 10.98.
That puts the fuel bill at $23.34 per MWh when gas costs $3 per MMBtu and $62.25 at $8, and it puts one gigawatt of load, served around the clock, at 180 million cubic feet of gas a day. Power plants as a group took 35.8 Bcf/d in 2025, 39% of everything the country consumed, so these small ratios add up to the largest single use of natural gas in the United States.
Two EIA heat rates for one fleet
A heat rate is the fuel energy a plant puts in for each kilowatt-hour it sends out. EIA's glossary defines it as “a measure of generating station thermal efficiency commonly stated as Btu per kilowatthour,” and notes that heat rates are typically expressed as net heat rates, meaning they are measured against the electricity that leaves the plant after its own use. Lower is better: a plant with a lower heat rate squeezes more electricity out of each cubic foot.
The Electric Power Annual carries two gas heat rates that are easy to confuse. Table 8.1 is an operating heat rate: for each fuel, the fleet's actual fuel burn against its actual generation in the year, built from the plant-level Form EIA-923 and Form EIA-860 reports. It covers electric utility and independent power producer plants and leaves out combined heat and power plants and every commercial and industrial plant. Table 8.2 is a tested heat rate: the rate each unit reports at full-load conditions, averaged by prime mover and weighted by net summer capacity. The first measures what the fleet did, including part-load running, starts and stops. The second measures what the equipment can do at its best operating point.
Table 1. Average operating heat rate by fuel, US electric utility and independent power producer plants, 2015 to 2025
| Year | Natural gas (Btu/kWh) | Gas, MMBtu per MWh | Gas, Mcf per MWh | Gas, implied efficiency | Coal (Btu/kWh) | Petroleum (Btu/kWh) | Nuclear (Btu/kWh) |
|---|---|---|---|---|---|---|---|
| 2015 | 7,869 | 7.869 | 7.60 | 43.4% | 10,495 | 10,687 | 10,458 |
| 2016 | 7,863 | 7.863 | 7.59 | 43.4% | 10,493 | 10,811 | 10,459 |
| 2017 | 7,803 | 7.803 | 7.53 | 43.7% | 10,465 | 10,834 | 10,459 |
| 2018 | 7,811 | 7.811 | 7.54 | 43.7% | 10,481 | 11,095 | 10,455 |
| 2019 | 7,725 | 7.725 | 7.46 | 44.2% | 10,551 | 11,205 | 10,442 |
| 2020 | 7,725 | 7.725 | 7.46 | 44.2% | 10,655 | 11,259 | 10,446 |
| 2021 | 7,689 | 7.689 | 7.42 | 44.4% | 10,583 | 11,224 | 10,429 |
| 2022 | 7,740 | 7.740 | 7.47 | 44.1% | 10,689 | 11,166 | 10,448 |
| 2023 | 7,721 | 7.721 | 7.45 | 44.2% | 10,745 | 11,465 | 10,452 |
| 2024 | 7,754 | 7.754 | 7.48 | 44.0% | 10,777 | 11,200 | 10,443 |
| 2025 | 7,781 | 7.781 | 7.51 | 43.9% | 10,647 | 10,969 | 10,443 |
Source: EIA, Electric Power Annual, Table 8.1, fetched November 3, 2026. The conversions are straight division: MMBtu per MWh is Btu per kWh divided by 1,000; Mcf per MWh divides by 1,036 Btu per cubic foot (EIA, British thermal units); efficiency is 3,412 Btu per kWh divided by the heat rate.
The gas fleet's operating rate improved from 7,869 Btu per kWh in 2015 to a low of 7,689 in 2021, then drifted back up to 7,781 in 2025, 1.2% above the 2021 low. Coal ended the period higher, 10,647 against 10,495 in 2015, after a low of 10,465 in 2017. EIA's tables do not say why gas slipped after 2021. Table 8.2 shows that the tested combined cycle rate was lower in 2025 (7,535) than in 2021 (7,580), so the drift is not a story of the equipment itself getting worse. A more likely contributor is how the fleet was run, but the data here cannot prove it.
What each kind of gas plant burns per MWh
Gas fleets are not uniform, and the spread between the best and worst plant type is bigger than any year-to-year movement in the average. Table 2 takes the 2025 tested rates from Table 8.2 and converts each into the units a fuel buyer uses.
Table 2. Natural gas burned per MWh by prime mover, tested heat rates, 2025
| Prime mover | Btu per kWh | MMBtu per MWh | Mcf per MWh | Implied efficiency | Mcf per hour for 100 MW | Change since 2015 |
|---|---|---|---|---|---|---|
| Combined cycle | 7,535 | 7.535 | 7.27 | 45.3% | 727 | -1.6% |
| Internal combustion (reciprocating engines) | 8,853 | 8.853 | 8.55 | 38.5% | 855 | -5.0% |
| Steam generator (boiler and turbine) | 10,293 | 10.293 | 9.94 | 33.1% | 994 | -0.8% |
| Gas turbine (simple cycle) | 10,975 | 10.975 | 10.59 | 31.1% | 1,059 | -2.9% |
Source: EIA, Electric Power Annual, Table 8.2 (natural gas column), from Form EIA-860, fetched November 3, 2026. Rates are reported at full-load conditions and weighted by net summer capacity. Conversions use 1,036 Btu per cubic foot and 3,412 Btu per kWh and are straight division and multiplication.
A combined cycle plant uses the exhaust heat of its gas turbine to raise steam for a second turbine, which is why it reaches 45.3% on this measure while a simple-cycle turbine reaches 31.1%. Put in gas terms, the turbine burns 45.7% more gas per MWh than the combined cycle plant: 10,975 divided by 7,535 is 1.457. The gap is 3.44 MMBtu of gas on every MWh, which at a delivered price of $4 is $13.76 per MWh. That cost difference is one reason simple-cycle turbines are the units kept for the peak hours, while combined cycle plants carry the long hours in between.
The boiler-and-turbine steam units, at 10,293, burn 6.2% less gas per MWh than the turbines but far more than the combined cycle plants. Against a coal steam unit tested at 10,040 the gas boiler needs 2.5% more heat per kWh, a small gap that matters later: it makes an old gas steam plant a near substitute for a coal plant on fuel cost. Reciprocating engines, at 8,853, are the other plant type that matters for new small installations such as on-site generation at a data center or an industrial site, and they improved the most since 2015, by 5.0%.
Why the fleet average sits between the plant types
From Btu per kWh to cubic feet of gas
Three conversions carry the whole calculation, and EIA publishes all of them. A kilowatt-hour of electricity equals 3,412 Btu, a cubic foot of natural gas contains 1,036 Btu, and a therm is 100,000 Btu. The heat content of the gas EIA tracks as delivered to consumers in the United States was 1,036 or 1,037 Btu per cubic foot in every year from 2020 to 2025, so the factor barely moves from year to year, though it varies by state, from about 917 in Hawaii to 1,096 in Washington in 2025.
Take the 2025 fleet rate. A rate of 7,781 Btu per kWh is 7,781,000 Btu per MWh, or 7.781 MMBtu. Dividing by 1,036 Btu per cubic foot gives 7,510.6 cubic feet, which is 7.51 Mcf per MWh. In the units that appear on a gas bill, that is 75.1 Ccf or 77.8 therms for each megawatt-hour. The reverse also works: one cubic foot of gas generates about 0.133 kWh. EIA's own answer to this question, which uses 2022 data, gave 7.42 cubic feet per kWh for utilities and independent power producers, and the 2022 operating rate of 7,740 divided by 7.42 implies about 1,043 Btu per cubic foot, within 1% of today's factor. The units guide covers the bill-side conversions in detail.
One caution comes before any comparison with a manufacturer's figure. EIA says it typically uses gross heat content, the higher heating value, which counts the energy used to vaporize water formed in combustion. A heat rate quoted on the lower heating value, or against gross rather than net output, is on a different basis. The 1,036 and the 7,781 above are consistent with each other and with the rest of EIA's statistics, and they should not be mixed with a datasheet number without checking the basis.
Fuel cost per MWh with gas from $2 to $8
Fuel cost per MWh is the heat rate in MMBtu per MWh multiplied by the gas price in dollars per MMBtu. It has no other terms, so it is exactly linear: each extra dollar of gas adds the heat rate in dollars to every MWh. For the fleet average, that is $7.78 per MWh for every $1 per MMBtu, and for a combined cycle plant, $7.54.
Table 3. Fuel cost in dollars per MWh by delivered gas price and plant type (2025 tested and operating heat rates)
| Plant type (Btu/kWh) | $2 per MMBtu | $3 per MMBtu | $4 per MMBtu | $5 per MMBtu | $6 per MMBtu | $7 per MMBtu | $8 per MMBtu |
|---|---|---|---|---|---|---|---|
| Combined cycle (7,535) | $15.07 | $22.61 | $30.14 | $37.68 | $45.21 | $52.75 | $60.28 |
| US fleet operating average (7,781) | $15.56 | $23.34 | $31.12 | $38.91 | $46.69 | $54.47 | $62.25 |
| Reciprocating engines (8,853) | $17.71 | $26.56 | $35.41 | $44.27 | $53.12 | $61.97 | $70.82 |
| Steam generator (10,293) | $20.59 | $30.88 | $41.17 | $51.46 | $61.76 | $72.05 | $82.34 |
| Simple-cycle gas turbine (10,975) | $21.95 | $32.93 | $43.90 | $54.88 | $65.85 | $76.83 | $87.80 |
| For comparison: US coal fleet at $2.42 per MMBtu (10,647) | $25.77 | $25.77 | $25.77 | $25.77 | $25.77 | $25.77 | $25.77 |
Source: heat rates from EIA Electric Power Annual Tables 8.1 and 8.2 (fetched November 3, 2026); coal delivered cost of $2.42 per MMBtu is the 2025 annual average in EIA Electric Power Monthly Table 4.1. Each product is heat rate times price. Fuel only: no variable operating costs, start-up fuel, capacity payments or pipeline demand charges.
Fuel cost per MWh against delivered gas price
Dollars per MWh, gas at $2 to $8 per MMBtu, against coal at its 2025 delivered price
Data behind this chart
| Delivered gas, $ per MMBtu | Combined cycle | Gas steam unit | Coal fleet |
|---|---|---|---|
| $2 | $15.07 | $20.59 | $25.77 |
| $3 | $22.61 | $30.88 | $25.77 |
| $4 | $30.14 | $41.17 | $25.77 |
| $5 | $37.68 | $51.46 | $25.77 |
| $6 | $45.21 | $61.76 | $25.77 |
| $7 | $52.75 | $72.05 | $25.77 |
| $8 | $60.28 | $82.34 | $25.77 |
Sources: EIA Electric Power Annual Tables 8.1 and 8.2; EIA Electric Power Monthly Table 4.1 (2025 coal, $2.42 per MMBtu). Fuel only. Fetched November 3, 2026.
Delivered price is what a plant pays, and it is usually above Henry Hub. EIA's Natural Gas Annual put the price of gas delivered to electric power consumers at $4.01 per Mcf in 2025, which is $3.87 per MMBtu at 1,036 Btu per cubic foot, against a Henry Hub spot average of $3.52. The premium over the hub, which covers pipeline transport and local conditions, ran from 35 cents in 2025 to $1.35 in 2021 across the six years in Table 6. A plant whose fuel cost is quoted at the hub price is understated by that much per MMBtu, which at the fleet rate is $2.72 to $10.50 per MWh. The Henry Hub guide explains what the benchmark does and does not capture.
Where prices stand today
The Henry Hub spot price was $2.76 per MMBtu on October 27, 2026, the last day in EIA's release of October 28. At the fleet rate that is $21.48 of fuel per MWh and, for a combined cycle plant, $20.80, before any delivery premium. This is a one-day snapshot of a price that moves daily. The monthly average for August 2026 was $2.78, and the Natural Gas Monthly put gas delivered to power plants at $3.22 per Mcf that month, or $3.11 per MMBtu. For a later reading, the natural gas price page carries the current price.
The right-hand end of Table 3 is not hypothetical. The Henry Hub monthly average for January 2026 was $7.72, which prices the fleet average at $60.07 per MWh, and the daily spot price reached $30.72 in the week of January 19, which would be $239.03 of fuel per MWh for the same plant. The guide to why gas prices move sets out the storage, weather and demand conditions behind spikes like that one. Plants with contracted supply paid less than the spot extreme, but the spread between a $2.76 day and a $30.72 day, $21.48 against $239.03 of fuel for the same MWh, shows how far outside the table the price can go.
One gigawatt, in cubic feet per day
The same conversions produce a rule of thumb for scaling gas supply: one gigawatt of constant load, which is a thousand megawatt-hours every hour, takes the heat rate in MMBtu each hour. At the fleet rate that is 7,781 MMBtu an hour, 186,744 MMBtu a day and 180.3 MMcf a day at 1,036 Btu per cubic foot.
Table 4. Natural gas burned by 1 GW of constant load, by heat rate
| Basis | Btu per kWh | MMBtu per hour | MMcf per day | Bcf per day | Bcf per year |
|---|---|---|---|---|---|
| Combined cycle, tested | 7,535 | 7,535 | 174.6 | 0.175 | 63.7 |
| US fleet, operating average | 7,781 | 7,781 | 180.3 | 0.180 | 65.8 |
| Reciprocating engines, tested | 8,853 | 8,853 | 205.1 | 0.205 | 74.9 |
| Simple-cycle turbine, tested | 10,975 | 10,975 | 254.2 | 0.254 | 92.8 |
Source: heat rates from EIA Electric Power Annual Tables 8.1 and 8.2; 1,036 Btu per cubic foot from EIA. Constant output for 24 hours a day and 8,760 hours a year. MMcf per day = MMBtu per hour x 24 / 1,036 x 1,000 / 1,000; Bcf per year = MMBtu per hour x 8,760 / 1,036 / 1,000.
A gigawatt of load is 0.50% of the 35.8 Bcf/d the whole power sector burned in 2025, so one large project barely moves the national balance, even though its own meter sees 180 MMcf a day. Power burn is seasonal as well: Natural Gas Monthly shows power plants taking 48.5 Bcf/d in July 2025 and 50.2 Bcf/d in August 2026, against the 35.8 annual average.
A check against the national total
The per-MWh numbers should add up to the national figure, and they nearly do. EIA's Electric Power Monthly reports 1,811 TWh of gas-fired generation in 2025 across all sectors. At the fleet rate that is 13.6 trillion cubic feet of gas, or 37.3 Bcf/d, against the 35.8 Bcf/d EIA reports delivered to the electric power sector. The bottom-up figure is 4.1% high, and the likely reason is scope: the all-sector generation total includes industrial and commercial plants and combined heat and power units whose fuel is counted elsewhere, and Table 8.1 excludes them from the heat rate. The monthly check is tighter. For July 2025, 201 TWh of generation at 7,781 implies 48.7 Bcf/d, and the reported delivery was 48.5, a difference of 0.4%.
One more ambiguity belongs in any gigawatt calculation: whether the gigawatt is load or capacity. Table 4 is per GW of generation running at full output all year, which is a load factor of 100%. EIA lists 513.4 GW of natural gas net summer capacity in 2025, and its plants generated 1,811 TWh, which is an average output of about 40% of that capacity. The two EIA tables do not share exact scope, so treat the percentage as approximate. Per GW of installed capacity, then, the 2025 average burn was roughly 0.070 Bcf/d, about 39% of the round-the-clock figure. Quoting “a gigawatt of gas plant uses X” without saying which gigawatt can be off by a factor of two and a half.
A data center campus, in gas
The Department of Energy's December 2024 release on the Lawrence Berkeley National Laboratory data center report found data centers used about 176 TWh in 2023, 4.4% of US electricity, up from 58 TWh in 2014, and projected a share of 6.7% to 12% by 2028. A flat 176 TWh a year is an average draw of 20.1 GW. If every one of those kilowatt-hours came from gas at the fleet rate, the burn would be 3.6 Bcf/d. It does not: the grid supplies a mix, gas produced 41% of US utility-scale generation in 2025, and a data center on the grid does not cause a particular plant to run. The arithmetic below is for the case where it does: gas generation sized to the campus, in front of or behind the meter.
Table 5. Gas needed to serve a constant data center load, by generation type
| Campus load | Generation | MMcf per day | Bcf per year | Fuel cost per year at $3.87 | Fuel cost per year at $6 |
|---|---|---|---|---|---|
| 100 MW | Combined cycle (7,535) | 17.5 | 6.37 | $25.5 million | $39.6 million |
| Reciprocating engines (8,853) | 20.5 | 7.49 | $30.0 million | $46.5 million | |
| Simple-cycle turbines (10,975) | 25.4 | 9.28 | $37.2 million | $57.7 million | |
| 300 MW | Combined cycle (7,535) | 52.4 | 19.11 | $76.6 million | $118.8 million |
| Reciprocating engines (8,853) | 61.5 | 22.46 | $90.0 million | $139.6 million | |
| Simple-cycle turbines (10,975) | 76.3 | 27.84 | $111.6 million | $173.1 million | |
| 1,000 MW | Combined cycle (7,535) | 174.6 | 63.71 | $255.4 million | $396.0 million |
| Reciprocating engines (8,853) | 205.1 | 74.86 | $300.1 million | $465.3 million | |
| Simple-cycle turbines (10,975) | 254.2 | 92.80 | $372.1 million | $576.8 million |
Heat rates from EIA Electric Power Annual Tables 8.1 and 8.2 (tested rates); 1,036 Btu per cubic foot from EIA. Constant load at the generator output for 8,760 hours; no transmission losses, backup generation, or cooling load beyond what the stated campus load already includes. $3.87 is the 2025 delivered price to power plants (EIA Natural Gas Annual, $4.01 per Mcf); $6 is an illustrative higher price. Fuel only.
Three readings come out of Table 5. A 100 MW campus on combined cycle burns 17.5 MMcf a day, which is 6.37 Bcf a year, and a 1 GW campus ten times that. The choice of machine moves the answer by 46% between the best and worst rows, and the difference compounds with price: on the 1,000 MW case, switching from combined cycle to simple-cycle turbines at $3.87 gas adds about $117 million in fuel a year. And the price matters nearly as much as the machine: the same combined cycle plant at $6 gas spends 55% more than at $3.87.
The table says little about a data center that stays connected to the grid. That case depends on the marginal plant at each hour and on contracts, neither of which any public table reveals. What the table does give is a scale test for a proposal. A developer who announces gas-fired self-supply for 1,000 MW needs a supply lateral good for roughly 175 MMcf a day on firm combined cycle terms and as much as 254 MMcf a day on turbines, and a fuel budget that runs from $255 million a year (combined cycle at $3.87) to $577 million (turbines at $6). Each additional 100 TWh a year of load served entirely by fleet-average gas would take 2.06 Bcf/d, which is 5.7% of the power sector's 2025 gas burn.
When coal is cheaper than gas
Gas and coal plants compete on fuel cost in the dispatch order, and the heat rate converts a fuel price in dollars per MMBtu into a cost per MWh. A coal unit is cheaper on fuel when its price times its heat rate falls below the gas price times the gas unit's heat rate. Solving for the gas price gives the switching rule:
The fuel-only switching price
Break-even delivered gas price ($ per MMBtu) = delivered coal price ($ per MMBtu) x coal heat rate / gas heat rate.
With 2025 averages, coal at $2.42 and rates of 10,647 and 7,781, the multiplier is 1.368, so break-even gas is $3.31. Against a combined cycle plant (7,535) the multiplier is 1.413 and break-even is $3.42. Against a gas steam unit (10,293) it is 1.034 and $2.50.
Gas below the break-even price runs ahead of coal on fuel alone. Gas above it falls behind. Because the multiplier is greater than one for the efficient gas plants, gas can cost more per MMBtu than coal and still win the dispatch: a combined cycle plant can pay about 41% more per MMBtu than a coal plant and break even. The same arithmetic shows why an old gas boiler, with almost the same efficiency as a coal plant, competes almost price-for-price.
Table 6. Delivered gas price, coal-parity price and generation by year, 2020 to 2025
| Year | Henry Hub spot | Gas delivered to power ($/MMBtu) | Coal delivered ($/MMBtu) | Break-even gas price | Gas fuel $/MWh | Coal fuel $/MWh | Cheaper on fuel | Gas generation, year on year | Coal generation, year on year |
|---|---|---|---|---|---|---|---|---|---|
| 2020 | $2.03 | $2.40 | $1.92 | $2.65 | $18.55 | $20.46 | Gas | +2.4% | -19.9% |
| 2021 | $3.89 | $5.24 | $1.98 | $2.73 | $40.26 | $20.95 | Coal | -2.9% | +16.1% |
| 2022 | $6.45 | $7.25 | $2.36 | $3.26 | $56.11 | $25.23 | Coal | +6.8% | -7.4% |
| 2023 | $2.53 | $3.38 | $2.51 | $3.49 | $26.08 | $26.97 | Gas | +7.1% | -18.8% |
| 2024 | $2.19 | $2.77 | $2.47 | $3.43 | $21.46 | $26.62 | Gas | +3.5% | -3.4% |
| 2025 | $3.52 | $3.87 | $2.42 | $3.31 | $30.12 | $25.77 | Coal | -3.1% | +12.7% |
Sources: EIA Henry Hub spot price, annual (release of October 28, 2026); EIA Natural Gas Annual price of gas delivered to electric power consumers (2025 preliminary), divided by that year's heat content of 1,036 or 1,037 Btu per cubic foot; EIA Electric Power Monthly Table 4.1 (coal, all sectors) and Table 1.1 (net generation, all sectors); heat rates from Electric Power Annual Table 8.1 for the same year. All fetched November 3, 2026. Break-even, fuel cost per MWh and year-on-year changes are computed from those inputs. Fuel only.
In five of the six years the cheaper fuel is the one whose generation rose, as the rule predicts. In 2020, 2023 and 2024 gas was cheaper on fuel, gas generation grew and coal generation fell. In 2021, delivered gas at $5.24 was nearly double the $2.73 break-even; coal generation rose 16.1% and gas generation fell 2.9%. In 2025 it happened again at a smaller scale. Delivered gas of $3.87 was 56 cents above the $3.31 break-even, coal generation rose 12.7% to 735 TWh, and gas generation fell 3.1%, the first drop since 2021.
2022 breaks the pattern. Delivered gas of $7.25 was far above the $3.26 break-even, and coal still lost 7.4% of its generation while gas gained 6.8%. Fuel cost is only one input to dispatch. A coal plant can only displace gas if it is available, has coal on the ground and is not retired, and the table cannot say which of those held in 2022. Demand also changes from year to year, and weather and renewable output change the call on both fuels, so a year-on-year change in generation is a noisy test of any price rule. The pattern across the six years is suggestive and not a model.
The 2026 reading
For August 2026 the pieces are in. Coal was delivered at $2.47 per MMBtu, which at the 2025 heat rates makes break-even $3.38. Gas delivered to power plants cost $3.11, which is $0.27 below the break-even, so gas was cheaper on fuel: $24.18 per MWh against $26.30 for coal. The generation data lean the same way. Gas was below the break-even in every month from March to August 2026 (Table 7). From January to August, coal-fired generation was 8.7% below the same months of 2025 and gas-fired generation 2.6% higher. These are year-to-date generation totals for all sectors from Electric Power Monthly, and the heat rates are those of 2025, since 2026 values are not yet published.
Table 7. Gas against coal on fuel cost, March to August 2026
| Month | Gas delivered to power ($ per Mcf) | Gas delivered ($ per MMBtu) | Coal delivered ($ per MMBtu) | Break-even gas price | Gas below break-even by |
|---|---|---|---|---|---|
| March | $3.21 | $3.10 | $2.40 | $3.28 | $0.19 |
| April | $2.85 | $2.75 | $2.42 | $3.31 | $0.56 |
| May | $2.83 | $2.73 | $2.44 | $3.34 | $0.61 |
| June | $3.27 | $3.16 | $2.52 | $3.45 | $0.29 |
| July | $3.47 | $3.35 | $2.49 | $3.41 | $0.06 |
| August | $3.22 | $3.11 | $2.47 | $3.38 | $0.27 |
Sources: EIA Natural Gas Monthly, price of gas delivered to electric power consumers (release of October 30, 2026); EIA Electric Power Monthly Table 4.1, coal delivered cost, total all sectors (2026 values preliminary). Conversion at 1,036 Btu per cubic foot, 2025 heat rates of 10,647 (coal) and 7,781 (gas) and all other columns follow from them. Fetched November 3, 2026.
What an average heat rate hides
The rule is a fuel-cost comparison and nothing more. It leaves out variable operating and maintenance costs, which differ by plant, and the fuel burned in starting a unit. It treats the national average delivered prices as if one plant faced them, though coal prices vary by basin and gas by pipeline. It ignores emissions costs, which fall on coal more heavily. It also ignores plant availability and the minimum run levels that keep some coal plants on when gas would be cheaper. For decisions about a particular plant, the delivered prices that plant pays and its own heat rate replace every national average in the formula.
Table 8. Carbon dioxide per MWh of fuel burned, by plant type
| Plant type | MMBtu per MWh | kg CO2 per MMBtu | kg CO2 per MWh | Pounds CO2 per MWh |
|---|---|---|---|---|
| Gas, combined cycle | 7.535 | 52.91 | 399 | 879 |
| Gas, US fleet average | 7.781 | 52.91 | 412 | 908 |
| Gas, simple-cycle turbine | 10.975 | 52.91 | 581 | 1,280 |
| Coal, US fleet average | 10.647 | 95.99 | 1,022 | 2,253 |
Sources: EIA carbon dioxide coefficients (from EPA), natural gas 52.91 kg per MMBtu and coal (all types) 95.99 kg per MMBtu, fetched November 3, 2026; heat rates from Electric Power Annual Tables 8.1 and 8.2. Combustion emissions only, before methane leakage or mining emissions. Kilograms converted at 2.20462 pounds per kilogram.
The same heat rate that sets the fuel bill sets the carbon. The average coal MWh emitted about 1,022 kg of CO2 at the plant, about 2.5 times the fleet-average gas MWh at 412 kg, because coal carries about 1.8 times the carbon per MMBtu and needs about 37% more MMBtu per MWh. A simple-cycle turbine, at 581 kg, is still well below coal on combustion carbon, though it burns the most gas of any plant type in Table 2.
Carrying these figures into a model
Choose the heat rate by the question. For how much gas the whole fleet burns, use the operating rate from Table 8.1 (7,781 for 2025) and EIA's power-sector delivery volumes to check the answer. For what a particular type of new plant will burn at full output, use the tested rate for its prime mover from Table 8.2. For a plant that will cycle or run at part load, add margin that neither table gives you.
Convert once and label the basis. The chain from the table to the burner tip is Btu per kWh, divided by 1,000 for MMBtu per MWh, divided by 1.036 for Mcf per MWh, multiplied by the MW of load for Mcf per hour, then by 24 for Mcf per day. Divide by 1,000,000 for Bcf per day. A factor-of-1,000 error slips in easily because MMcf, Mcf and MMBtu differ by exactly that. A quick test catches it: one gigawatt should come out near 0.18 Bcf/d, about half a percent of the power sector's national burn.
Price the fuel at the delivered price, not the hub. A shift of $1 in the Henry Hub price moves fuel cost by the heat rate in dollars per MWh, and EIA's annual data for 2020 to 2025 put delivered prices 35 cents to $1.35 above the hub. Keep the date next to every price, because the daily number used here, $2.76 for October 27, 2026, will not be the number next week. The weekly storage report guide shows the data that most often moves it, and the Henry Hub, TTF and JKM comparison shows the export-linked prices that gas can earn abroad instead of in a power plant.
Heat rate and power-plant gas use questions
How much natural gas does a power plant burn per MWh?
The average US gas-fired plant burned 7.781 MMBtu of gas per MWh in 2025, which is 7,781 Btu per kWh in EIA Table 8.1 and about 7.5 Mcf at 1,036 Btu per cubic foot. Tested by plant type, a combined cycle plant burns 7.535 MMBtu per MWh (7.3 Mcf), reciprocating engines 8.853 (8.5 Mcf), a boiler-and-turbine steam unit 10.293 (9.9 Mcf) and a simple-cycle turbine 10.975 (10.6 Mcf).
How many cubic feet of natural gas make one kilowatt-hour of electricity?
About 7.5 cubic feet at the 2025 fleet average: 7,781 Btu divided by 1,036 Btu per cubic foot is 7.51. A combined cycle plant needs about 7.3 cubic feet and a simple-cycle turbine about 10.6. EIA’s own fuel-use answer, written with 2022 data, gave 7.42 cubic feet per kWh.
How much natural gas does a gigawatt of power plant burn?
A gigawatt of load served around the clock by plants at the 2025 fleet-average heat rate burns about 180 MMcf a day, or 0.18 Bcf/d, and about 66 Bcf in a year. Per gigawatt of installed capacity the average is far lower, roughly 0.07 Bcf/d, because gas capacity ran at an estimated 40% of its summer rating in 2025.
How much natural gas does a data center use?
It depends on whether the data center runs on its own gas generators or draws from the grid. A 100 MW campus running flat out on a combined cycle plant would burn about 17 MMcf a day, or 6.4 Bcf a year. On simple-cycle turbines the same load needs about 25 MMcf a day. Served from the grid, only the gas share of the supply mix, about 41% of US generation in 2025, applies on average.
At what gas price does coal become cheaper than gas for power?
The fuel-only break-even is the delivered coal price in dollars per MMBtu multiplied by the coal heat rate and divided by the gas heat rate. With 2025 coal at $2.42 and fleet-average rates it was $3.31 per MMBtu delivered gas. For a combined cycle plant against the average coal plant it was $3.42. The figure ignores variable operating costs, emissions costs and whether the coal plant is available.
Why does EIA publish two different gas heat rates?
Table 8.1 reports an operating heat rate for the fleet in actual use, 7,781 Btu per kWh for gas in 2025, from fuel burned and electricity generated. Table 8.2 reports tested heat rates by plant type under full-load conditions, weighted by capacity: 7,535 for combined cycle and 10,975 for gas turbines. They answer different questions and should not be mixed in one calculation.
Data and sources, all fetched November 3, 2026: U.S. Energy Information Administration, Today in Energy, Natural gas-fired electricity conversion efficiency grows as coal remains stable (August 21, 2017), and Electric Power Annual, Table 8.1, average operating heat rate, Table 8.2, average tested heat rates by prime mover and Table 4.3, existing capacity by energy source (2025). EIA Electric Power Monthly, Table 1.1, net generation by energy source and Table 4.1, receipts, average cost and quality of fossil fuels (data through August 2026). EIA natural gas data: Henry Hub spot price, daily, monthly and annual (release of October 28, 2026); natural gas consumption by end use, deliveries to electric power consumers, annual and monthly delivered prices and heat content of natural gas delivered to consumers (releases of October 30, 2026; 2025 values preliminary). EIA, British thermal units, How much coal, natural gas, or petroleum is used to generate a kilowatthour of electricity?, glossary: heat rate, glossary: heat content and carbon dioxide emissions coefficients. U.S. Department of Energy, DOE Releases New Report Evaluating Increase in Electricity Demand from Data Centers (December 20, 2024). Conversions, sums, break-even prices, year-on-year changes and percentages are computed from those sources.