Drill two parallel holes in the ground until you reach rocks that are hot enough ( about 200C). Then, pump cold water into one hole and wait for it to rise in the other hole at a higher temperature. The heated water will turn to steam which can power a generator or heat your home. In recent years, geothermal energy has gained popularity due to its pros:
1. Environmentally Friendly
Most of us can agree that carbon emissions generated by power stations make a great contribution to climate change. A clear pro is that geothermal energy is one of the cleanest energy options out there. There is no waste produced when extracting geothermal power. Besides,one should not worry about greenhouse gasses, since they are practically inexistent. No transportation and extensive drilling is required, which basically minimizes even more the environmental impact of exploring geothermal power.
2. Heating and Cooling Functions
Unlike other sources of alternative energy, geothermal energy has a clear advantage: providing your home with both heating and cooling. In the winter, the ground will be used like your own solar panel. The heat pump will circulate the water, which absorbs the heat from the earth and use it to heat up your home. In the summer, the process is reversed. The Earth acts like a heat sink, drawing the excess heat from your home. Cool air is then distributed through the home, providing air conditioning.This is achieved because the Earth has a constant temperature of 55 F year round.
Read more: The Future of Geothermal Energy
3. Geothermal Energy is Free and Available on All 7 Continents
That’s right. Just like the other sources of alternative energy: wind or solar, planet Earth has massive reserves of heat underneath the crust. Geothermal basins and hot dry rocks reservoirs are widely spread around the world. Besides being free, this heat source is inexhaustible and available day and night.
4. Lower Temperature Sites are Now Feasible
Innovation and recent improvements in technology have made it possible to explore more sources of geothermal energy. Until recent years, it was viable to focus only on the sites that provide the most heat ( geothermal basins). Recently, it was determined that even lower temperature sites ( 80 C -150C ) can cover the heating and electricity needs of the area. For example, in the UK,it’s now possible to extract heat from hot dry rocks and sedimentary basins. These pockets of low-temperature geothermal energy can be found just a few meters below ground.
Resources are now available at sites like: Wessex and Worcester, Cheshire, Eastern England, Larne and Lough Neagh.
5. Geothermal Energy has Become More Affordable
Recent investments in building new extraction sites are growing the market for geothermal energy. The industry has become more competitive and new methods for installing heat pumps have been developed. The good news is that the prices for heat pumps and geothermal energy have lowered. Homeowners have now more options to choose from.It is estimated that choosing geothermal will significantly reduce your heating and electricity bill. For every unit of electricity used for the process, 4 units of heat are produced.
There is a lot more to say about the pros of geothermal energy and massive potential that can be generated from it. But now we are going to look at the cons of geothermal power:
1. Geothermal energy resources vary from region to region
Although geothermal basins are widely spread, not all areas of the earth are 100% covered. On the map below you can see the distribution of such resources as well at the intensity of heat that can be provided. Since is not feasible to transport geothermal energy, the distribution and consumption needs to take place locally. Therefore, only dwellings close to the source can benefit from geothermal heating and electricity.
source: Geothermal Resources Council
2. High Investments Needed to Build Exploration Sites
Another con of geothermal energy is the amount of economic resources needed to build the plants. To get an idea of it, America's Department of Energy has allocated up to $338m in funds for 123 geothermal projects.However, comparing to the cost of building a wind or solar energy plant, geothermal energy has lower exploration costs than the other 2.
Read more: Advantages of Geothermal Energy
3. Time Consuming
A lot of research has to be engaged to determine if an exploration site is technologically and commercially feasible. Financing is allocated once the resource has been proved. Attention needs to be given to:the location, market conditions, geological potential and developer specs. The average development time for a commercial geothermal project is 7.5 years until actual operation.
4. Minor Seismic Activity
Another disadvantage of geothermal energy arises when building large scale exploration plants. This is due to the injection of high pressure water into the ground, which causes a small earthquake.It can pose a challenge, especially in developing countries where infrastructure and pipeline systems are not very sophisticated. However none of these quakes have registered a magnitude above 3; and mostly, they are not noticed by public.
Overall, geothermal energy has a lot of potential and new technologies will make it easier to explore and minimize risks. There is no perfect source of energy so far and in the case of geothermal energy, the pros outweigh the cons.