Geothermal energy: Costs and savings

Although geothermal energy is one of the least known among renewable energies, it is growing in recent years, since it has the best seasonal performance by offering a constant temperature in the subsoil, the source of its origin.
Its efficiency is the result of the continuous flow that is stored under the surface of the earth in the form of heat. And, unlike other systems, the current weather conditions do not influence.

The prices and rates of the geothermal installations will depend on the type of building or installation. Thus, a detached house of about 300 m2 would require a geothermal pump of about 15 kW, with an estimated cost of 24,000 euros.

In the case of a leisure establishment of about 2,000 m2, it would require a 100 kW geothermal pump and the price of the investment would be 145,000 euros.

If we talk about office buildings of 5,000 m2, it would require a geothermal pump of 5,000 kW and the cost of the installation would be about 320,000 euros.

Geothermal energy is more efficient the larger the building or facility is. Thus, in the single-family housing the price of the kilowatt is more expensive than in an office building.

Talking about costs, geothermal energy has substantially lower costs if we compare it with natural gas or diesel plus a contribution of cold production through chillers.

So in a comparison with the two energies, it would be the following:

  • Although the initial investment would be more expensive in the geothermal with a cost of 24,000 euros compared to 14,500 of the natural gas plus chiller or 16,000 of the most cooled gas oil, its redeem is faster.
  • A geothermal installation, if we compare it with a diesel one plus a chiller, would be redeemed by the fourth year. And if we compare it with the installation of natural gas plus chiller, the amortization of the geothermal installation would be reached in the seventh year.
  • If we only refer to the annual energy cost, only in the first year we would save half the money with geothermal energy compared to diesel and this saving would double if we compare it with diesel.
  • This cost ratio excludes the installation of domestic hot water production (DHW) with solar panels. The geothermal energy produces the DHW in a renewable way and it would be an additional cost to the natural gas and diesel installations for the production of DHW in a renewable way according to the regulations for the new construction works.

IPMA

INGENIERÍA Y PROTECCIÓN DEL MEDIO AMBIENTE
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