Assessment of primary energy savings by means of CHP systems in domestic energy supply

In this paper the assessment of primary energy savings of combined heat and power (CHP) systems is described by a primary energetic comparison of a coupled supply system (CHP plant, boiler and power plant) with a separated supply system (boiler and power plant). The plant-side power to heat ratio and the demand-side power to heat ratio are discussed as important system parameters for primary energy savings. The method suggests a theoretical potential of primary energy savings, which depends on plant-side characteristics only. The technical potential of primary energy savings is the consequence of plant-side and demand-side characteristics. In this paper an example application is presented for dynamic simulation of two different insulation standards in Germany, using the reference load profiles of the German technical guideline VDI 4655.