There is the external combustion CHP unit. This system works well within domestic projects and can replace a properties existing boiler. The External Combustion Unit is the most popular option to for many households. Whereas your average boiler uses the heat it has generated for the heating and hot water system, the CHP boilers allow the burnt gas to drive a turbine which creates an electrical current. The electricity made can be used for household appliances as well as heating your home.
When focusing on larger projects, it is better to look at the internal combustion type of CHP unit. This is because the heat that would normally be wasted through the engine cooling systems or exhausts is captured and allows the home to reuse it to heat the homes hot water system.