Geothermal
Geothermal technology uses energy from the earth’s crust to generate heat or electricity. The energy can be
accessed by drilling wells into underground reservoirs to bring the hot geothermal fluid to the surface. The heat
can then be converted into electricity or used directly in heating applications.
In the geothermal field, the term “energy conversion” refers to power-plant technology that converts the heat
of geothermal fluids into electricity. There are three types of geothermal power plants currently in operation: dry
(or direct) steam, flash steam and binary-cycle plant. The plant type depends on the specific location of the
geothermal resource. Due to the variation in resources, such as composition, pressure and temperature of the
geothermal fluid, geothermal power plants must be designed according to an assessment of the site-specific
conditions in order to optimize the power generation efficiency. Unlike wind and solar power, electricity gener-
ated from geothermal sources is not intermittent, which means that it can provide reliable base-load power.
Box 5: Potential growth in geothermal power generation
The current global capacity of geothermal power is around 10.7 GW across 26 countries. Pike Research, a
market research and consulting firm, has projected that the total worldwide geothermal power capacity could
grow to 25.1 GW by 2020. The firm also estimated that there is a minimum of 190 GW of conventional geothermal
resources around the globe that can be exploited using currently available technologies.
Source: Ecoseed website “Global Geothermal Capacity Can Hit 25.1 GW by 2020: Research” (30 September 2011). Available from
www.ecoseed.org/geothermal/article/14-geothermal/11357-global-geothermal-capacity-can-hit-25-1-gw-by-2020-%E2%80%93-research
(accessed 06 March 2012).
