6.10 Geothermal Energy

geothermal basics

natural radioactive decay of elements deep in earth’s core gives off heat, driving magma convection currents which carry heat to upper portion of mantle, close to earth’s surface

geothermal for electricity

naturally heated water reservoirs underground are drilled into and piped up to surface (or water can be piped down into naturally heated rock layers)

ground source heat pump (geothermal)

heat absorbing fluid is pumped through a pipe into ground where it either takes on heat from ground, or gives off heat to ground

true geothermal heating

involves piping water deep into ground to be heated by magma and then transferring heat from water to building (diff. than ground source heat pump)

geothermal pros

potentially renewable (only if water is piped back into ground for reuse), much less CO2 emissions than FF electricity, no release of (PM/SOx/NOx/CO) as in case with FFs

geothermal cons

not everywhere on earth, mainly available in countries located on tectonic plates, hydrogen sulfide can be released (toxic and lethal to humans and animals), cost of drilling that deep can be high initally