Geothermal power is the use of geothermal
heat to generate electricity. Geothermal power supplies
0.416% of the world's energy. Geothermal comes from the
Greek words geo, meaning earth, and therme, meaning heat.
Prince Piero Ginori Conti tested the first geothermal
power plant on 4 July 1904, at the Larderello dry steam
field in Italy.
If heat recovered by ground source heat
pumps is included, the non-electric generating capacity
of geothermal energy is estimated at more than 100 GW
(gigawatts of thermal power) and is used commercially
in over 70 countries.
During 2005, contracts were placed for
an additional 0.5 GW of capacity in the United States,
while there were also plants under construction in 11
other countries
Estimates of exploitable worldwide geothermal
energy resources vary considerably. According to a 1999
study, it was thought that this might amount to between
65 and 138 GW of electrical generation capacity 'using
enhanced technology'.
A 2006 report by MIT that took into account
the use of Enhanced Geothermal Systems (EGS) concluded
that it would be affordable to generate 100 GWe (gigawatts
of electricity) or more by 2050 in the United States alone,
for a maximum investment of 1 billion US dollars in research
and development over 15 years.
The Nesjavellir Geothermal Power Plant in Iceland
The Nesjavellir Geothermal Power Plant in Iceland
The MIT report calculated the world's
total EGS resources to be over 13,000 ZJ, of which over
200 ZJ would be extractable, with the potential to increase
this to over 2,000 ZJ with technology improvements - sufficient
to provide all the world's energy needs for several millennia.
