When all the energy sources for heating a greenhouse are considered, geothermal is really a King (or a Queen) among them.

There are several reasons for this and here are the most important ones:

The cost of energy is very low and in some cases can be even none. There are cases of geothermal energy sources with water temperatures of 80 ° C (176 °F) and higher, water quality good enough for human consumption, water is going out on the surface with pressure of 2 bar (29 psi) so no geothermal pump needed and no cost for electricity. So in this case we can say that this is a true free energy source.

Low equipment cost. No big and expensive equipment needed like boilers and such. Geothermal energy heat exchangers are small, compact, cheap and easy to replace and service. Geothermal well pumps are much cheaper then boilers, burners and condensers.

It is easy to have a backup heat exchanger and a geothermal well pump, for quick replacement in times of service or failure. Which is not the case with big boilers for biomass and such.

If water is warm enough, 65 ° C (149 °C) and higher, the response to sudden heat demands is very quick. Which is difficult with biomass boilers.

With gas burners, gas is used to produce heat. This heat is then transferred to greenhouse heating system water. So with geothermal energy source, heat is already in a form of warm water, which is very convenient.

No need for fuel storage and manipulation and transport costs.

On the other hand geothermal energy is not available everywhere, so finding it can be a challenge. But that’s for another post…