Power-heat coupling, or PHC for short, is a method for generating mechanical energy, which is usually converted directly into electricity, and thermal energy, which can be used either for general heating purposes or for process heat. The heat produced is used on location if possible, but it can also be fed into a long-distance heating network. The energy us usually produced using combustion engines or with gas/steam turbines in connection with a generator. However, steam engines, Stirling motors and fuel cells can be used for power-heat coupling purposes.

The advantages of PHC

The clear advantage of power-heat coupling as opposed to conventional separate production of electricity and heat lies in the much more efficient utilization of the primary energy involved. A maximum of just 40% of the fuel energy used to generate electricity in modern fossil fuel power plants are converted into usable heat. In older plants, after accounting for performance losses, the efficiency is much lower. The rest, so-called waste heat, is lost. By putting this thermal energy to use for heating other purposes, as in thermal power plants, the total fuel efficiency can be increased to around 90%.

The principles of power-heat coupling