CO2 Emissions for Power Generation Category CO2 Emissions (g-CO2/kWh) Coal Thermal 975.2 Oil Thermal 742.1 LNG Thermal (steam power) 607.6 LNG Thermal (combined cycle) 518.8 Nuclear 21.6 – 24.7 Hydroelectric 11.3 Geothermal 15 Photovoltaic 53.4 Wind Power 29.5 Source: Japanese Agency for Natural Resources and Energy