It sounds like you want a "ground source geothermal" system using a heat pump. Heat pump technology is getting quite mainstream in North America and special designs have been marketed for Canada with it's colder winters (the cooling pipes get well below freezing point of water so the working temperature range needs to accommodate -15 C to 70 C). You can check out IGSHPA (International Ground Source Heat Pump Association) who has done many long term studies on heat pump designs and has an accreditation process and education. I believe there is a European organization similar to IGSHPA.
IGSHPA - Down to Earth Energy
My intent is to do things differently though. Heat pumps suck heat out of the ground and then sun shining on the ground or pavement on the surface brings the ground back to the warm temperature. Even bore holes going down 200 feet (60 meters) are still using the sun's heating more then the earth's internal heating. This makes the ground into a solar panel. The problem is that the heat pump still needs power to run and solar cells are hard-pressed to provide enough power and it also needs to be stored in batteries. Instead, I plan to heat the ground up to the temperature needed and insulate the surface. This requires lots of solar heat in the hot part of the summer and the hot part of the day to be stored for use in the winter and at night. Heat can also be made by pumping hydraulic oil through pipes with the pumps powered by wind. The friction of the oil against oil makes heat all along the pipe. The definitive source of information on annual heat storage is the book "Passive Annual Heat Storage" by John Hiat.
Earth Sheltered Homes - Rocky Mountain Research Center
I was then thinking of storing other temperatures for freezer, refrigeration, hot water and cooking and making those temperatures using smaller heat pumps powered by solar or using outside temperatures (for cold) or solar heat panels for the higher heat. These would then be used as needed in specially made appliances (refrigerators, freezers, stoves, ovens, hot water tanks, driers) that use these stored temperatures.
Another thing to consider is the research done in Northern Sweden and Norway where they have homes that cannot be provided electricity grid, or fuel due to the remote location and no solar or wind power due to tall trees and dark winters when above the Arctic circle and they are built on bedrock so ground source geothermal is not an option either. Their solution is just to have a very air-tight and very well insulated house and to have a very efficient heat exchanger to bring in fresh air and then just use body heat of the people and the heat from cooking and computers to heat the home.