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.
Great points brought up here. So, what exactly is not using too much? I am an electrical contractor, and have to say in the past 3 years I have hooked up more geo units than I had in the previous 12. It is a concept that is growing, I hope it doesn’t end up being flawed in some way, or maybe possibly there’s still a renewable form of energy we haven’t discovered yet. Great post, though…really gets one thinking.
By: Paul Hundrieser on August 28, 2009
at 1:55 am
Yes, Geothermal energy is renewable energy. Geothermal power is energy generated by heat stored in the earth. Geothermal power generation refers to the collection of absorbed heat derived from underground resources. Geothermal resources range from shallow ground to hot water and rock several miles below the Earth’s surface, and even further down to the extremely hot molten rock. Wells over a mile deep can be drilled into underground reservoirs to tap steam and very hot water that can be brought to the surface for use in a variety of applications.
By: Cleantech Investor on October 8, 2009
at 6:41 am
Yes, Geothermal Energy is renewable. Geothermal energy is energy that comes from the heat within the earth. We all know that the earth’s core is filled with magma as well as steam and hot water. You can find here (http://www.new-energy-portal.com/information/earth/geothermal) a lot information about Geothermal Energy
By: newenergy on March 9, 2010
at 5:17 am