Combined heat and power (CHP) is the simultaneous conversion of primary energy into useful heat and mechanical or electrical energy. It is the most efficient principle for the energetic use of fuels, regardless of whether they are fossil or renewable. We can no longer afford to waste usable energy. The Federal Association of Combined Heat and Power therefore promotes the expansion of CHP, regardless of the type and size of the systems, the area of application and the energy source used. The aim is to increase the efficiency of energy conversion in order to conserve resources and reduce emissions that are harmful to the environment and the climate.