Is nuclear energy climate-friendly?

If we take into account the entire life cycle of a nuclear power station (that is, from the extraction and transport of raw materials, through the construction of the station and the generation of electricity itself, right through to the decommissioning of the station and the storage and treatment of waste), the CO₂ emissions from nuclear energy per kWh generated are comparable to those from renewable energy.

Low carbon footprint

When the full life cycle of a nuclear power station is taken into account (including the extraction and transport of raw materials, the construction and decommissioning of the power station, and finally the storage and treatment of waste), the CO₂ emissions from nuclear energy are similar to those from renewable energy sources.

In a power station, energy is produced through a series of energy conversions. The combustion of fuel or nuclear fission (nuclear energy) releases heat, which turns water into steam. This steam drives a large turbine, which in turn drives an alternator. This alternator converts mechanical energy into electrical energy.

Discover how a nuclear power plant works

The main difference compared with fossil-fuel power stations (such as coal- or gas-fired power stations) is that no CO₂ is emitted during electricity generation in nuclear power stations. No fuel is burnt.

IPCC / GIEC (2014)

The Intergovernmental Panel on Climate Change (IPCC, part of the United Nations) has calculated CO2 emissions (in grams per kilowatt-hour) from various energy sources. As nuclear power stations emit very little CO2, they contribute to the fight against climate change.

The IPCC study gives the following (average) figures by energy source:

  • Wind turbines: 11 g CO₂eq/kWh
  • Nuclear power stations: 12 g CO₂eq/kWh
  • Solar panels: 27 g CO₂eq/kWh
  • Gas-fired power stations: 490 g CO₂eq/kWh
  • Coal-fired power stations: 820 g CO₂eq/kWh

Further information: IPCC report (2014)

UNECE / CEE-ONU - Life Cycle Assessment of Electricity Generation Options (2022)

A study by the UNECE (United Nations Economic Commission for Europe), which is part of the United Nations, has compared the climate impact of different energy sources used for electricity generation (gas, coal, nuclear and renewables), measured across their entire life cycle.

One of the main conclusions is that, of all energy sources, nuclear energy emits the least CO₂ (measured over its entire life cycle), occupies the less land and requires the fewest raw materials (metals, minerals) to produce a given amount of electricity, compared with other sources of electricity (wind turbines, solar panels, hydroelectricity, gas-fired power stations, coal-fired power stations).

In other words, nuclear energy is a sustainable source of energy.The UNECE study provides the following (average) figures by energy source:

  • Nuclear energy: 6 g CO₂eq/kWh
  • Onshore wind energy: 12 g CO₂eq/kWh
  • Offshore wind energy: 17 g CO₂eq/kWh
  • Solar panels: 31 g CO₂eq/kWh
  • Gas-fired power stations (without carbon capture and storage, or CCS): 458 g CO₂eq/kWh
  • Gas-fired power stations (with CCS): 157 g CO₂eq/kWh
  • Coal-fired power stations (without CCS): 924 g CO₂eq/kWh
  • Coal-fired power stations (with CCS): 302 g CO₂eq/kWh
  • Concentrated Solar Power (CSP): 63 g CO₂eq/kWh
  • Hydroelectric power stations: 62 g CO₂eq/kWh

Further information: UNECE study (2022)