Geothermal energy is defined as heat from within the Earth2. It is another source of renewable energy that is present in the form of geothermal reservoirs.
Geothermal reservoirs are essentially pools of water that seep into the earth’s crust and subsequently heated by magma to superhot temperatures.
It is considered as a renewable source of energy as the heat that emanates from Earth’s interior is limitless. This heat, which travels primarily by conduction, is estimated to be equivalent to 42 million megawatts (MW) of power. This energy can last for billions of years so ensuring an inexhaustible supply of energy.
These reservoirs are generally not seen as they are underground however when there are cracks or openings in the earth’s crust, it can appear in the form of geysers or hot springs. For areas that have an abundance of such geothermal reservoirs like Iceland and United States, they can be used to generate electricity via the steam generated or utilised in the form of heated water for bathing cooking and washing of clothing.
In this article I have summarised geothermal energy facts which include its pros and cons and why it is considered as a potential source of energy to replace fossil fuels.
Why Geothermal Energy? What are the Advantages?
Renewable Energy Source
As the name “renewable” suggests, geothermal energy is continually replenished and the steam that is used to generate electricity can also be recycled for usage again. It also not dependent on the weather elements unlike solar or wind power.
Generates Zero Pollutants
There is no burning and so no emission of fumes is involved when geothermal energy is utilised to generate electricity.
Plethora of Uses for Geothermal Energy
The heated water since the time of the Romans has been used for bathing. Nowadays this water can be pumped from their underground reservoirs and channelled though pipes directly to faucets of homes and other buildings. Geothermal energy can also be used to generate electricity that are not only cleaner and will not be affected by the availability of sources since geothermal energy is a renewable source of energy.
One good example of its economic values is obvious for the Iceland. Electricity generated using geothermal energy in Iceland is cheaper since no fuel is required therefore making her a perfect location for location of data centres for companies.
Data centres are important for companies as they contain information and the accounts of their customers therefore they will require massive amounts of electricity to power and to maintain them at a cool temperature to ensure their functionality. This monetary savings in cheaper electricity is coupled with the effect that data storage can now be a greener industry.
There are also government incentives that aid in promoting the usage of geothermal energy. The GEA or Geothermal Energy Association of United States hands out subsidies of up to 30% for consumers who had purchased qualified residential alternative energy equipment that include geothermal heat pumps.
Uses of Geothermal Energy
Geothermal energy is utilised in the various situations below:
Geothermal energy power stations
The naturally heated water/ or steam from the geothermal reservoirs can be used to generate green electricity. This can be accomplished by drilling wells into a geothermal reservoir that will bring the heated water(geothermal reservoir) to the surface.
The steam from the heated water will turn huge turbines that can be used for generation of electricity. Some examples include the Svartsengi in Iceland and The Geysers in United States.
Usage in farms and industries
Farms raising fishes for food and pets are using geothermal energy to warm their ponds and lakes to ensure the healthy growth of fishes. One example4 will be the production of vegetables during winter in Tuscany, Central Italy that are grown in fields heated by natural steam.
Romans4 had used geothermal water for the treatment of eye and skin disease. In Pompeii, it was utilised for heating of buildings. There was also the establishment of a first known “health spa” in Belgium in 1326 at natural hot springs.
Heating for houses and buildings
Via a geothermal heat pump, natural heat can be utilised to heat buildings in the winter. While in summer, it can also be utilised to collect heat from the buildings and transfer it into the ground.
According to the GeoHeat Centre website3, the total amount of geothermal energy utilised in US for direct heating has a total capacity of 470 MW or enough to power 40,000 average-sized houses.
Disadvantages of Geothermal Energy… Some Facts
Even though geothermal energy is readily available inside the Earth, some reservoirs will cool down over time.
Some locations of geothermal reservoirs could not be accessed readily for tapping as they are not always located near the surface.
It is very expensive to set up a well for extracting geothermal energy from underground and also to set up a geothermal energy heat pump.
1. R.Owen. Energy from inside our planet: Geothermal Power. 32pp. The Rosen Publishing Group 2013
2. http://www.eia.gov/energyexplained/index.cfm?page=geothermal_home (accessed 30th April 2015)
3. http://www.geoheat.oit.edu/whatgeo.htm (accessed 30th April 2015)
4. http://geo-energy.org/Basics.aspx (accessed 30th April 2015)
Published: 28th October 2013
Last Updated 1st May 2015