- Geothermal energy - New types of renewable energy
In addition to water, wind, biomass and hydrogen energy, there is also geothermal energy. This is energy derived from naturally heated water or steam like a geyser.
Geothermal energy is in use in Iceland, Kenya, Nicaragua, New Zealand, Philippines and other countries. In 2011, it generated a combined 211,200 MW of electrical power capacity in these countries.
The largest facility in the United States is the Geysers north of San Francisco. The United States generates 3,000 MW of geothermal energy a year and is the world leader. However, this energy source only powers a small part of the country.
There are other ways of harnessing renewable energy such as pulling heat from underground, using the tides and OTEC. These methods are still in development.
Geothermal heat pumps involve pulling energy from underground by burying pipes that extract heat from the ground. This can be used in a conventional home.
Tidal barrage consists of a dam that is built across the mouth of the bay with turbines mounted into the structure. The incoming tide generates power. Cities such as New York and San Francisco are building turbines to produce power.
OTEC or ocean-thermal energy conversion involves using the temperature difference between the surface water and colder ocean water to produce power. This is an experimental new method of harnessing energy.