Commodities obtained through the transformation processes from other energy commodities. The national energy balance covers the following derived energy commodities: - hard coal briquettes, - brown coal briquettes, - products of coking plants (coke, semi-coake, coke-oven gas, benzol, tar), - refined oil products, - manufactured gaseous fuels (e.g. blast furnace gas, converter), - heat in steam or hot water, - electricity.