Geothermal energy

Geothermal energy

Main article: Geothermal power
Geothermal energy harnesses the heat energy present underneath the Earth. The hot rocks heat water to produce steam. When holes are drilled in the region, the steam that shoots up is purified and is used to drive turbines, which power electric generators.

Pros:
Geothermal energy does not produce air or water pollution if performed correctly
Once a geothermal power station is implemented, the energy produced from the station is practically free. A small amount of energy is required in order to run a pump, although this pump can be powered by excess energy generated at the plant.
Geothermal power stations are relatively small, and have a lesser impact on the environment than tidal or hydroelectric plants. Because geothermal technology does not rely on large bodies of water, but rather, small, but powerful jets of water, like geysers, large generating stations can be avoided without losing functionality.

Cons:
Geothermal energy is only sufficient as source of power in certain areas of the world. These regions require the presence of hot rocks near the surface to warm the water. The depth of these rocks must be shallow enough that one can drill down to them, and the type of rock also plays a role as it must be easy to drill through.
Some geothermal sites are prone to running out of steam, when their water is not heated at a high enough temperature to generate steam pressure. This can render the site useless in terms of energy production for decades.
Drilling holes underground may release hazardous gases and minerals from deep inside the Earth. It can be problematic to dispose of these subsidiary products in a safe manner.
Drilling deep holes and pumping water into them may cause unexpected seismic events, such as earthquakes, in the surrounding area.[citation needed]