Schematic of the earth, thanks to
Swiss DHM project.(17 KB picture)
Schematic of the earth, thanks to
Swiss DHM project.
(17 KB picture)
Geothermal energy is produced from the vaste amounts of heat within the earth. Today 20 countries produce power with natural geothermal steam rising from deep wells drilled into hot permeable aquifers. The capacity of all the geothermal power plants amounts to 7,300 MW electric. With nearly 2,300 megawatts of installed geothermal power, geothermal energy is the United State's second largest grid-connected renewable electricity source (after hydropower). Geothermal energy is essentially non-polluting.
Schematic of Deep Heat
Mining concept, thanks to Swiss
DHM project.
(27 KB picture)
While present geothermal plants rely on naturally occuring hot water/steam fields, a much greater energy potential can be recovered by drilling into hot rock and circulating liquid in a closed loop. This is variously called Hot Dry Rock, Deep Heat Mining, or Enhanced Geothermal Systems. The figure shows such a system where the fluid (water) is circulated in a closed loop. Cold water is pumped into the reservoir, is heated as it flows through fractures in the rock, returns to the surface, and the heat energy is extracted.
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