The heat pump does not create heat it only moves heat from one area to another. Moving heat is much more efficient than creating heat. The heat pump can be 200% to 300% efficient, this means that for every dollar you provide in operating cost you will receive two to three dollars of heat.
The only difference is that the ground becomes the medium where the heat is moved to or from. Since the ground temperature is more constant, the efficiency of the ground source is higher. The Geothermal Heat Pump can be 300% to 400% efficient. This means that for every dollar of operating cost you provide to the ground source, you will receive three to four dollars of heat.