• Figures are based on gross generation and do not account for cross-border electricity supply.
• Primary energy is measured using the "substitution method" (also called "input-equivalent" primary energy). This method is used for non-fossil sources of electricity (namely renewables and nuclear), and measures the amount of fossil fuels that would be required by thermal power stations to generate the same amount of non-fossil electricity. For example, if a country's nuclear power generated 100 TWh of electricity, and assuming that the efficiency of a standard thermal power plant is 38%, the input-equivalent primary energy for this country would be 100 TWh / 0.38 = 263 TWh = 0.95 EJ. This input-equivalent primary energy takes account of the inefficiencies in energy production from fossil fuels and provides a better approximation of each source's share of energy consumption. You can find more details in the Statistical Review of World Energy's methodology document.