A method to determine primary energy savings of CHP plants considering plant-side and demand-side characteristics

Cogeneration or combined heat and power (CHP) is considered as an important key technology towards efficient energy supply. While CHP is used in industrial systems for a long time, in domestic energy supply CHP technologies are penetrating recently. Domestic energy supply systems with CHP plants differ in plant-side and demand-side characteristics. The effects of feed-in of CHP generated electricity is analyzed in detail. In this paper we develop an assessment method for primary energy savings by means of a primary energetic comparison of a coupled supply system with a separated supply system. The plant-side power to heat ratio and the demand-side power to heat ratio are discussed as important parameters for primary energy savings. The method leads to a theoretical potential of primary energy savings, which only depends on plant-side characteristics. The technical potential of primary energy savings is the consequence of both, plant-side and demand-side, characteristics.