About Geothermal Energy
Clean, renewable and plentiful, geothermal energy holds huge promise
Around the world, geothermal energy—generated from heat that originates at the earth's core—is widely and affordably produced, providing enough power to satisfy the electrical needs of well over 60 million homes.
Where it all starts
Geothermal's origins begin at the earth's molten iron core, approximately 4,000 miles beneath the surface where temperatures exceed those found on the surface of the sun. This heat gradually makes its way up through an 1,800 mile-thick mantle of magma and rock to the earth's crust, a relatively "thin" layer of matter that extends 3-5 miles under the earth's oceans, and 15-35 miles beneath land masses.
Turning steam into electricity
It is here that the heat interacts with rock and naturally occurring water to create super heated water. Accessed by drilling wells that range from 1,000 - 11,000 feet deep, the steam or hot water is flowed or pumped to the earth's surface where, simply put, on-site steam turbines or a binary power plant system convert it into electricity.
In the absence of underground water sources, the earth's heat is stored and trapped in non-porous rock
To produce steam and subsequent electricity, water is pumped down deep boreholes to interact with the hot dry rock and produce super heated water. This emerging process is called EGS (enhanced or engineered geothermal systems) and has the potential of allowing producers to access and enhance these deeper, hotter, more energy "rich" geothermal reservoirs—which exist in most areas of the world.
According to a recent International Geothermal Association survey, countries or locales producing geothermal power include the following:
||Papua New Guinea
Many other countries are in the process of developing geothermal reservoirs for renewable power generation.