Which type of heating system in the new building?

But photovoltaics are not free either; they have purchase and later maintenance costs. Leute, there is no free lunch, until proven otherwise I still consider the gas boiler in a properly insulated house combined with underfloor heating to be cost-effective. Since we are forced to install some kind of eco-gadget, we chose solar for hot water, which is the cheapest to purchase, and with the equinox on March 21st I turned off the heating; our hot water is now provided solely by the solar system until the end of September. This also saves a few cubic meters of gas.