With a heat pump, energy is extracted from the air, the ground or groundwater, before being converted into usable energy to heat the building. Heat pumps are highly efficient, which greatly reduces the consumption of fossil fuels. Although heat pump system are powered by electricity, you can still reduce overall power consumption by generating all or part of the power required on site, e.g. with solar panels.
Cogeneration involves simultaneously producing electricity and heat with a motor powered by a single fuel, which can either be a fossil fuel - fuel oil or natural gas - or a renewable fuel - biogas or biomass. The revolutions of the motor generate electricity, while the system cooling the motor produces heat. This heat can be used for various heating purposes, such as heating the building and heating water for sanitation or processes.