Geothermal = Renewable Energy

Geothermal energy draws sustainable power from the natural and abundant heat of the earth’s core; the same heat that drives volcanic activity. This thermal energy is contained in the rock and fluid in the earth’s crust and has been used by mankind for centuries - natural hot-springs were first used for cooking and bathing, and ancient Roman baths used thermal waters to provide bathing water and to heat the bathhouses as well. Following the lead of their ancestors in the bathhouses, Italians in Tuscany were the first to generate electricity from geothermal water in 1904 – the plant is still in operation today. In 1958 a small geothermal power plant began operating in New Zealand, in 1959 another began in Mexico, in 1960 in the USA. Today geothermal energy is used in more than 20 countries to generate electricity, including Iceland, the USA, Japan, Italy, Indonesia, New Zealand, Mexico, the Philippines, Kenya, Costa Rica, and Nicaragua.

Geothermal energy can be found in several forms, but only two are currently accessible to supply energy on a large scale:

• In hydrothermal reservoirs of steam or hot water trapped in rock. These reservoirs are concentrated in particular regions as a result of geological processes (typically volcanic).
   
• In the heat of the shallow ground. This “earth energy” is found everywhere and is the normal temperature of the ground at shallow depths. Earth energy is not enhanced by geological process and therefore is not as hot as other geothermal sources.    

Hydrothermal reservoirs are tapped by drilling underground into permeable zones of super-heated water and using energy conversion technologies (steam turbines) to generate electricity (or to produce hot water for direct use). The geothermal energy is conveyed by a carrier fluid – in hydrothermal reservoirs this fluid is found naturally in the form of groundwater which is injected back into the ground as part of the energy production process.

Benefits of Geothermal Energy

> Geothermal power is a clean and renewable source of energy - a geothermal plant continuously and perpetually delivers power with over 95% reliability.

> So, once developed, geothermal energy provides long-term, stable revenues at very low cost.

> Moreover, when compared to other types of power plants geothermal power plants have a very small footprint on the local area in which they are situated.