On 10/21/2010 2:02 AM harry spake thus:

The problem is that PV panels are only round 5% efficient..

As U stated elsewhere in this thread, you're waaaaay off. Even current
ordinary off-the-shelf panels achieve 12% efficiency. But that's nowhere
near the limit: for instance, solar concentrator cells, like these from
Opel Solar (http://www.opelinc.com/concentrators.html) can get up to 36%
(see their data sheet at
http://www.opelinc.com/datasheets/Da...eet-Mk-Id.pdf).

More expen$ive, sure, but even the price of these will drop eventually.

But I have to say I agree totally with what Aemeijers said he solar
power does NOT necessarily mean only photovoltaic power (electricity).
Years ago, when I was involved with the alternative energy movement, the
emphasis was on what was called "direct use of the sun's energy", or
"passive solar". This includes both solar heating (domestic hot water
and living space) as well as sun "tempering" to reduce air-conditioning
needs in hot climates, through building design, tree plantings, etc.

Think of it as the "apple orchard" concept: you naturally pick the
low-hanging fruit first. Rather than massive investment in high-tech
production plants, with all their environmental problems (not to mention
energy consumption and expense), why not reduce energy by the easiest
and most cost-effective means *first*? Like by designing homes and
buildings that aren't energy sieves or energy pigs.

As Amory Lovins put it so well decades ago, our energy use regime is
like a bathtub with a leaking drainplug, and our only solution seems to
be to pour more and more water into it to keep it full. Instead, how
about just replacing the goddamn drainplug?


--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)