Return on Investment
The usual time for a standard household to return their investment using geothermal energy is around 7-10 years. However, these values can be decreased significantly, the bigger the building or the building complex is to be provided by geothermal energy, it may be decreased, even down to 3 years. After that, your household or your company is provided with extremely inexpensive energy.
As an example: Iceland saves around $100 million per year through the avoided oil imports to heat its households and buildings. More than 90% are being supplied this way.
The heat extraction is considered renewable. The amount of heat extracted from the earth does not implore a significance on the general heat condition of our planet. Earth renews its heat constantly through different factors, some of them involving the decay of naturally appearing radioactive substances, such as potassium, uranium and thorium.
Furthermore, there are simple techniques to replenish nature’s resources by ourselves, usually through injection of certain amounts of water into prior used reservoirs.
Extraction of geothermal energy is considered sustainable. As sustainability and renewability are often used as synonyms, here are short explanation of the difference between them: renewable means usually describes a natural source of energy, that is being replenished constantly by natural processes. Most renewable energies are also called sustainable at the same time.
The term ‘sustainable energy source’ also describes an energy source that helps to conserve nature and its offered energy sources in order to ensure available energy for future generations, and to save the planet.
Read more: How Much Does a Geothermal System Cost?
Geothermal energy is considered sustainable in many ways. The reason for that are:
- The energy taken from the heat extracted is too minimal to have an effect on earth’s ecosystem. Also, the constant decay of natural radioactive materials, and other of earth’s activities replace the tapped heat.
- Geothermal energy causes nearly no pollution. The hot water that is coming up the pipes from the earth is used to drive turbines in order to generate electricity. No fuels are needed to work the turbines. The only pollution comes from the gases that are present in the earth, but the amounts are still significantly lower than any other energy source in use.
A Unique Approach for a Unique Situation
Geothermal energy can be harnessed through a variety of different techniques that can be applied to different geological criteria. A few examples include:
- Extracting heat through ground source heat pumps: This technique involves the immediate layers of our planet. In a depth of about 15 meters, the temperature of the ground is mostly constant. This is because at this depth, the temperature levels are not being affected by seasonal changes, therefore staying at around 10 ͒C. In the summertime, this is enough to supply air conditioners, whereas in the wintertime, it can be used to produce heat.
- Utilisation of certain rock formations: As an example, the region of Cornwall consists of a lot of granite. Granite is an igneous rock, being formed from lava and its residues. The process of final formation or cooling down takes thousands of years, or even longer. Therefore, minerals have enough time to grow into the granite, radioactive ones as well. The usual natural radioactive substances to be found in granite are radium, uranium and thorium. Although they can be in almost any other type of rock as well, granite’s formation time usually causes higher concentrations of these substances.The radioactivity causes higher temperatures, so the water coming back up to the surface can be used more easily in e.g.: turbines.
- Drilling boreholes into great depths: The usual depth needed to be reached is around 100 meters. After that, cold water is being injected. After passing through the heated up area, it comes out another borehole, that had been created precisely to get this water at a certain spot. This kind of technique usually works best in areas with tectonic activity, such as volcanoes, etc.
In Conclusion, the advantages are many, while the disadvantages are kept very low. Especially in these times of massive pollution and rising fuel costs, geothermal energy is well worth its money.