It takes less energy to move heat than it does to produce it. A heat pump basically runs an air conditioner backwards, so rather than moving heat from inside a structure to outside, it moves heat from outside to in. With the right units, this works even in cold weather for the same reason a freezer gets warm on the outside - it’s moving heat from inside the (freezing) unit out.
Geothermal energy takes this concept a step further by putting the outside unit underground. Underground temperatures are more stable and moderate, so it’s easier (more efficient) to expel/collect heat, but also much more involved to install.
It takes less energy to move heat than it does to produce it. A heat pump basically runs an air conditioner backwards, so rather than moving heat from inside a structure to outside, it moves heat from outside to in. With the right units, this works even in cold weather for the same reason a freezer gets warm on the outside - it’s moving heat from inside the (freezing) unit out.
Geothermal energy takes this concept a step further by putting the outside unit underground. Underground temperatures are more stable and moderate, so it’s easier (more efficient) to expel/collect heat, but also much more involved to install.