Geothermal Power Plant
In the current energy scene, some of the major discussions in the media center around the renewability of a resource and whether it is green. While neither term is as objective as it might initially appear to be, it is the renewability of various energy sources that is particularly subject to debate.
What does renewable really mean? For an energy resource to be renewable means that it must be replenished naturally. The unstated implication is that this must happen on a human timescale. For example, the sun is the source of energy behind solar PV, solar thermal, hydroelectric and wind power and solar is considered renewable. It’s renewable because nothing we do to convert solar energy into electricity has an impact on the amount of sunlight that is available.
However, the sun won’t last forever and will not renew itself at some point. Clearly that point is well beyond our concern, but it does speak to the concept of time in regard to whether an energy source is renewable.
If solar energy is renewable, even though it is, in fact, finite, what happens if that timeframe shortens? At what point does an energy become non-renewable? 100 years? 50? 5? Fossil fuels do not renew in any kind of human timeframe but some biofuels do. In the case of these types of questions, the timeframes are rather defined and they are renewable.
What about Geothermal energy? Geothermal energy taps into the vast amount of heat in the earth’s core, but when heat is removed from the core, does it renew or does it just deplete to an infinitesimally small degree?
Online research produces some amusing responses – some indicating that it’s renewable …if we do not use too much. However, this logic would make fossil fuels renewable too and that doesn’t pass muster.
Better arguments indicate that the heat in the earth’s core comes from radioactive decay of elements, which is effectively renewable. In terms of what is legally recognized to be renewable, geothermal makes the list and qualifies for inclusion in programs earmarked for renewable (and/or green) energy sources.
So, is geothermal green? Yes, green like the sun.
Why does the new data center in Iceland offer double the greenness you ask? Well read on.
