Choosing renewable resource (source)

When deciding which renewable resource to use (air, ground water, water from lake or river, ground source – geothermal - heat of rocks) it is necessary to consider many aspects, the most important are:

• what resources are available in the neighborhood and what are temperatures (e.g. temperature of underground water)
• what resources you are allowed to use according to the local regulation (e.g. in some countries it is prohibited to use underground water in others you should get special permission from the government)
• what is your climate (winter air temperature)
• how much money are you prepared to spend for the project (e.g. air sourced heat pump installation is probably the cheapest, ground sourced heat pump (geothermal) installation with vertical collectors is probably the most expensive)
• are you planning to use your heat pump also for water heater
• are you planning to use your heat pump also for cooling
• how much isolation coat are you planning to put on to your house and what would be the energy loss of your house
• what kind of heating are you planning to implement (low temperature floor heating, high temperature)
• what is or should be coefficient of heat pump performance (I will explain this term latter)

When considering described issues you should definitely involve someone who is familiar or even better professional in those calculations. At the end you should know all calculations, energy loss, primary source temperature, type of heating (e.g. floor heating) and other parameters.
For my project I have engaged one local professional who was very familiar with this numbers and calculations. I have paid to him 100 € and it was worth paying. Finally I have decided to use ground sourced heat pump with vertical underground collectors (geothermal).