This project deals with combustion installations with a rated thermal input exceeding 50 MW. Plants with a thermal input lower than 50 MW are, however, discussed where technically relevant because smaller units can potentially be added to a plant to build one larger installation exceeding 50 MW.

All kinds of conventional power plants (e.g. utility boiler plants, combined heat and power plants, district heating plants) used for mechanical power and heat generation are covered in this work. Industrial combustion installations are covered if they use conventional fuel. The commercial availability of the fuel on the market has been used as an indicator to identify conventional fuels. The criterion for classifying a fuel as a 'conventional fuel' is a known composition which remains relatively constant, and indeed is usually standardised. Coal, lignite, biomass, peat, liquid and gaseous fuels (including hydrogen and biogas) are regarded as conventional fuels. The use of waste as a secondary fuel is also covered in this work.