Water Heat Pumps
If you live close to a lake or a watercourse, lake water heat is a good option. Even if the water is under ice during the winter, the heat in it can still be extracted.
The collector hose is laid on the lake bed and held in place by weights. The principle is the same as for surface soil heat. A non-toxic liquid circulates in the hose. The temperature of the liquid is raised a few degrees by the heat in the water. By compression in the heat pump, the temperature of the liquid is raised and the heat is transferred to your radiators. This thermal energy can also be used to heat the domestic hot water.
The only work needed on your property is to dig a trench from the water to the house.