Mark Abramowitz via EV wrote:
Is solar thermal water heating *still* more efficient?
"Efficient" has a different meaning when your energy source is free. Energy efficiency usually means getting the most good out of a finite source of energy.
Suppose you have a limited roof area that can only collect 1 KWH of energy. PV cells might convert that into 150 watts of electricity. A solar water heat might convert it into 300 watts of heat in your water heater. Which is more useful to you?
But most roofs are so large that the amount of solar energy available is "limitless". You're limited more by what you can spend, and what appearance dictates. PV is more popular than thermal because it's cheaper. The efficiency is less, but you make up for it with more panels.
It's like the "ICE" solution wins. When you treat oil supplies as "limitless", then extremely inefficient ICEs are the popular choice, because it's cheaper.
-- In software development, there are two kinds of error: Conceptual errors, implementation errors, and off-by-one errors. (anonymous) -- Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
