Solar Hot Water heater, Was Re: [at-l] The State of theList Now windpower

[jbullar1 at twcny.rr.com (Jim Bullard)]

At 11:10 AM 12/20/2005 -0500, Nightwalker wrote:
>Jim Bullard <jbullar1@twcny.rr.com> wrote:
>:: At 05:33 PM 12/16/2005 -0500, John Soboleski wrote:
>::: The efficiency rating for geo exchange is somewhere between 300%
>::: and 600%, depending on the application.
>::
>:: 300% to 600%? You can extract 3 to 6 times the BTUs from the ground
>:: that are in there? At no cost? That doesn't make sense.
>::
>Jim, not seeing the stat and it's derivation, but I'm guessing that the
>claim is that you get 3 to 6 times the energy out that it costs to retrieve
>it. Mo betta?

The usual efficiency ratio of energy production is energy produced relative 
to energy expended. Unless the scientific law that matter and energy can be 
interchanged but not created or destroyed has been repealed, 100% is an 
impossibility much less 300 to 600%. Now if they are talking about relative 
cost of production, that a cost ratio or percentage not an efficiency ratio.