How Much CO2 Does a Wind Turbine Save?
In short: In the German electricity grid mix, an average of 344 g CO₂ is emitted per kilowatt-hour of electricity (source: UBA, 2025). Every kWh of wind power displaces this fossil share — a modern 6 MW turbine with an annual yield of 18 GWh therefore saves around 6,200 tonnes of CO₂ per year.
The Calculation
CO₂ savings [t/year] = annual yield [GWh] × emission factor [344 g/kWh] / 1,000
| Turbine | Annual yield | CO₂ savings/year | over 20 years |
|---|---|---|---|
| Old turbine 1.5 MW | ~3 GWh | ~1,000 t | ~20,000 t |
| Modern 3 MW | ~8 GWh | ~2,800 t | ~55,000 t |
| Modern 6 MW | ~18 GWh | ~6,200 t | ~124,000 t |
| 6 MW top site | ~23 GWh | ~7,900 t | ~158,000 t |
Grid Mix Comparison — Historical and Current
| Year | g CO₂ / kWh grid mix DE | Source |
|---|---|---|
| 2024 | 363 g | UBA 2024 |
| 2025 (preliminary) | 344 g | UBA 2025 |
The factor falls with each further expansion of renewables — good for the climate overall, but in purely arithmetic terms it reduces the CO₂ savings value of a single new wind turbine. As long as the grid mix is not entirely CO₂-free, the effect remains clearly positive.
Energy Payback
Modern onshore wind turbines typically recover the energy input for their manufacture and construction within under one year of operation. Over their 25-year service life they therefore deliver many times the manufacturing energy invested. This order of magnitude applies across the industry; specific values are reported in the manufacturers' life-cycle analyses (LCA).
Frequently Asked Questions
Why does the grid mix CO₂ value not fall faster?
Because coal and gas power plants are dispatchable and fill the gaps in the renewable generation profile. Only with extensive expansion of storage and flexibility will the remaining fossil share fall quickly.
Does the construction energy input really "cancel out"?
Yes — energy payback has been methodologically well established for decades. The LCA comparison with fossil electricity generation comes out clearly in favour of wind even when conservative assumptions are chosen.
Are there methodological debates?
Yes, above all about the right reference value: against which grid mix do you compare? The UBA factor (average) is the standard; some methods use the marginal mix — which is higher (fossil) in many hours and lower in others.
CO2 savings by turbine size – UBA factor, 20-year balance and energy payback