The term “energy mix” describes the relative contributions of each different energy source to consumption within a particular territory.
Those primary energy sources may be fossil fuels (oil, coal, natural gas), nuclear or renewables (wind, solar, methanisation etc.). They can be used to produce electricity, heat or fuel. The contribution of each energy source to the energy mix is expressed as a percentage.
The breakdown of the energy mix varies by country and by region, but also by time period (e.g. summer / winter), since it depends on energy demand, the resources available for use in the territory, and political choices.