Primary energy commodities are commodities obtained directly from natural resources both renewable and non-renewable. The national energy balance covers the following primary energy commodities: 1) non-renewable energy commodities: - hard coal, - brown coal, - fuel peat, - crude oil (including natural gas liquids), - natural gas. 2) renewable energy commodities: - solar energy, - wind energy, - fuel wood, -biomass, i.e. organic materials of biological origin from special energy cultivations or waste fuel, - geothermal energy, - hydro energy (natural flow) for electricity generation