Tuesday, December 4, 2012

Geothermal energy - Main advantages and disadvantages

Geothermal energy is basically a heat stored within the earth's core. Geothermal energy is far from being described as a perfect energy source, however, there are more advantages than disadvantages when discussing the geothermal energy.

Geothermal energy advantages:

Geothermal energy is renewable energy source. Geothermal energy is renewable energy source because earth’s heat is being constantly replenished by the radioactive decay of minerals at a rate of 30 TW. 

Geothermal energy is clean source of energy because geothermal power plants are connected with minimum carbon emissions, with most of them are equipped with emission-control systems to reduce the exhaust of greenhouse gases carried by drawn fluids.

Geothermal energy belongs to energy sources that can be directly used. Hot springs have been used for bathing since ancient times and in modern times geothermal energy is directly used to heat homes via geothermal heat pumps.

Geothermal energy is reliable source of energy that does not suffer from intermittency issue like this is the case with some other renewable energy sources, most notably solar and wind. Geothermal heat is available 24-7 and is therefore one of the most reliable renewable energy sources, a one that does not require energy storage solution in order to work reliably.

Geothermal power plants have minimal land and freshwater requirements unlike for instance solar energy which needs large area and plenty of water for cooling. Geothermal plants use only 3.5 square kilometers (1.4 sq mi) per gigawatt of electrical production and require just 20 liters of freshwater per MW/h.

Geysers, California was the subject of local depletion of geothermal resources.

Geothermal energy disadvantages:

The biggest disadvantage of geothermal energy are high upfront costs, most of which refer to exploitation and drilling. Geothermal power plant construction and well drilling currently cost about €2-5 million per generated MW of electricity.

Small number of countries that currently harness geothermal energy. Geothermal energy is currently being harnessed in only 24 countries of the world. The main reason why there aren't more countries involved is because geothermal power plants are currently cost-effective only in areas near tectonic plate boundaries though the recent technological advances such as EGS (enhanced geothermal systems) should significantly expand the range of viable geothermal resources in years to come.

The lack of qualified personnel needed to install geothermal systems. Geothermal energy use isn't widely spread or as popular as this is the case with solar and wind, which means that there is less qualified personnel available to hire and they also cost more.

Local depletion of geothermal resources. This has been the case in several well known geothermal sites such as Geysers. In order to avoid local depletion of geothermal resources extraction of geothermal energy must be closely monitored.

Enhanced geothermal systems can trigger earthquakes therefore severely affecting land stability if not done carefully.