How much CO2 does coal produce per kWh compared to gas?

Coal produces 820–1,200 g CO2/kWh, while natural gas produces 410–520 g — roughly half. But both are far more carbon-intensive than renewables (7–50 g/kWh).

What is the cleanest source of electricity?

Wind (7–15 g CO2/kWh) and nuclear (5–15 g) have the lowest lifecycle emissions, followed closely by hydropower (4–30 g) and solar (20–50 g).

How does nuclear compare to renewables for carbon?

Nuclear and wind have similar lifecycle emissions (5–15 g CO2/kWh). Nuclear is one of the lowest-carbon electricity sources available and provides reliable baseload power.

Why do my results differ from headline national averages?

Household size, climate, insulation, and equipment efficiency can move results away from averages. Personalized inputs are more useful for decisions.

Should I focus on efficiency or switching energy source first?

Usually both matter, but high-usage systems and inefficient equipment are often the best first targets for reducing emissions.

What are the lifecycle emissions of wind energy?

Onshore wind produces 7–15 g CO2 per kWh over its lifecycle, including manufacturing, installation, and decommissioning. Offshore wind is slightly higher at 12–23 g due to foundation construction.

Is coal vs gas vs renewables better in every country?

Not always. Country-level differences in grid mix, fuel factors, and behavior can shift outcomes. Use country-specific inputs for the most reliable result.

What is the long-term carbon footprint of coal vs gas vs renewables?

Long-term impact depends on lifecycle assumptions and duration of use. Annual and lifetime views should both be considered for decision-making.

Which input changes the result the most?

Usually location and usage intensity. For product comparisons, replacement frequency and lifespan also matter significantly.

What should I compare first for coal vs gas vs renewables?

Start with the default scenario, then adjust country and usage inputs. This reveals whether your local conditions change the ranking between options.

Coal vs Gas vs Renewables: CO2 Emissions per kWh

Q: Is natural gas really cleaner than coal?

In terms of CO2 at the point of combustion, yes — about 50–60% less. But methane leaks during extraction can reduce this advantage significantly. Gas is a transitional fuel, not a clean one.

Compare the lifecycle carbon emissions of different electricity sources: coal, natural gas, solar, wind, nuclear, and hydropower per kWh.

Last updated: March 30, 2026

Key Takeaway

Coal produces 820–1,200 g CO2 per kWh, natural gas 410–520 g, solar 20–50 g, onshore wind 7–15 g, and nuclear 5–15 g. Switching from coal to wind reduces electricity emissions by over 98%. Even natural gas (the cleanest fossil fuel) produces 25–70x more CO2 than renewables.

Adjust Your Comparison

Electricity (kWh): 1,000

Compare with country (optional)

Results shown for United States. Sources: IPCC AR6 WGIII — Annex III: Technology-specific Cost and Performance Parameters, Our World in Data — Carbon Intensity of Electricity.

Emissions Comparison

Coal

1,010

kg CO2

United States

1,010 kg CO2

Natural Gas

490

kg CO2

United States

490 kg CO2

Solar PV

kg CO2

United States

33 kg CO2

Wind (Onshore)

kg CO2

United States

11 kg CO2

Nuclear

kg CO2

United States

10 kg CO2

Hydropower

kg CO2

United States

16 kg CO2

Why Coal Is the Dirtiest Energy Source

Coal combustion produces the most CO2 per unit of electricity of any common energy source — 820–1,200 g CO2 per kWh depending on the coal type and plant efficiency. Beyond CO2, coal plants emit mercury, sulphur dioxide, nitrogen oxides, and particulate matter. Coal is responsible for approximately 30% of global CO2 emissions and is the single largest contributor to climate change.

Is Natural Gas Really Cleaner Than Coal?

Natural gas produces about 50–60% less CO2 per kWh than coal when burned. However, methane leaks during extraction and transport (the 'fugitive emissions' problem) can significantly reduce this advantage. When lifecycle methane leakage exceeds 3%, the climate benefit of gas over coal largely disappears. Natural gas is cleaner than coal, but it's still 25–70x more carbon-intensive than renewables.

The Real Cost of Cheap Fossil Fuel Electricity

The market price of coal and gas electricity doesn't include the health and climate costs of combustion. When pollution costs, healthcare, climate damage, and subsidy removal are accounted for, fossil fuels cost the global economy an estimated $5.9 trillion per year in subsidies and externalities (IMF, 2023). Renewables have no fuel cost, no air pollution, and their production costs have fallen 90% (solar) and 70% (wind) since 2010. Levelised cost of electricity (LCOE) for new solar and wind is now below coal and gas in most markets — making the energy transition economically compelling as well as climate-essential.

How Countries Are Decarbonising Their Electricity Grids

Grid decarbonisation is accelerating: the UK's grid fell from 500 gCO2/kWh in 2012 to under 180 gCO2/kWh by 2024. Germany peaked coal generation in 2013 and has cut it by 60%. India doubled renewable capacity between 2020–2024 while still relying on coal for 70% of electricity. The US added more renewable capacity in 2023 than in any previous year. The IEA projects that no new coal, oil, or gas field approvals are needed after 2021 to meet a net-zero 2050 pathway — meaning existing infrastructure, not new investment, determines the transition pace. Countries that accelerate grid decarbonisation create a compounding benefit: every electric vehicle, heat pump, and electric cooker purchased today becomes cleaner as the grid cleans up.