What are the advantages and disadvantages of geothermal energy?

Answer 1

Primarily, the earth generates internal heat by radioactive decay, which continuously rises and radiates from the surface. Harvesting this geothermal energy involves pumping water down a drilled shaft, deep into the earth where it collects heat, creating steam. The steam is then directed upward through another shaft to turbines that generate electricity. The recovered water, now cooled, is again pumped down the original shaft in a continuing cycle.

Advantages:

• Cleaner: energy source than fossil fuels.
• Base-load: energy source.
• Safer: to develop and use, than fossil fuels.
• Conserves: fossil fuels, still required in some applications,
• Contributes to diversity: of energy sources.
• Independent: of weather

Disadvantages:

Not universally available.

Emissions:

• 0 - 88 lbs of CO2 per megawatt-hour (comparatively negligible);
• trace amounts of Mercury, boron, arsenic, antimony, etc.
• Localized Depletion:In 3 oldest sites, use outruns energy renewal.
• Geological instability: Basel, Switzerland operation suspended (10,000 seismic events/6 days).
• Hazard: exploration entails significant risks.
• 20% failure rate: with significant harm to environment.

High Cost:

Drilling and exploration.

Corrosion maintenance can out-weigh benefit.

Answer 2

Geothermal energy is the energy obtained from the earth(geo) from the hot rocks present inside the earth. It is produced due to the fission of radioactive materials in the earth’s core and some places inside the earth become very hot. These are called hot spots. They cause water deep inside the earth to form steam. As more steam is formed, it gets compressed at high pressure and comes out in the form of hot springs which produces geothermal power.

To harness this geothermal energy, two holes are dug deep into the earth and cold water is pumped through the first one and steam comes out through the second long pipe which helps in generating electricity. The holes dug for harnessing geothermal energy result in lesser emission of greenhouse gases than due to burning of fossil fuels. Thus if used at a larger scale and more efficiently, it gives a hope to reduce global warming.

Geo-thermal energy is one of the rare forms of energy which is not directly or indirectly from solar energy. In areas where hot springs are found, hot springs baths are very common and enjoyable form of recreation. However, they need to be in a controlled environment since they cannot be accessed without proper supervision. We have earlier seen how it is harnessed, the process involved is a long and expensive one and not feasible in some areas.

Construction of geothermal energy plants can affect the seismic stability to a large extent. Even though there are lesser emissions, digging deep holes causes seismic disturbances which have led to earthquakes. :-)