Posted by G. R. L. Cowan on December 23, 2005, 12:15 pm
Your repeated making of this point with respect
to a closed cycle engine with a dish reflector
suggests you don't understand the dish reflector
is reflecting sunlight onto the hot side of the engine.
--- Graham Cowan, former hydrogen fan
boron as energy carrier: real-car range, nuclear cachet
Posted by Johnny on December 23, 2005, 3:37 pm
Well, closed-cycle didn't tell me much. I assumed that it was similar to
closed-loop power generation systems.
I looked up stirling engines, didn't know you were referring to such a
Fuel cost is still what solar does not pay for compared to
Posted by Derek Broughton on December 23, 2005, 4:30 pm
Except nobody mentioned combustion or uranium, and we _were_ talking about
solar. The fact that Dan saw fit to point out you were making a mistake
should at least have encouraged you to review your assumptions. "closed
cycle" doesn't tell you much, but "dish reflector" should have been a clue.
fwiw, I haven't yet seen any evidence that boiling hot water can be made to
provide electrical power on a household basis - but I'll be in line when
they come up with a working - simple - system.
Posted by Johnny on December 24, 2005, 12:56 am
Closed cycle indicated to me that there was some standard energy device
I apologize if anyone's feathers got ruffled.
I really wasn't aware that closed cycle was different from what I had seen
before in power generation.
Posted by Jeff Thies on December 23, 2005, 7:39 pm
But the cost of the PV is by far the dominant cost because it is so so
so much greater.
Here, electricity is 7 cents/kwh.
If PV were $/w, that's $000/kW.
The break even is 100,000 hours of full sun. That's at least 22 years
and probably more because you won't get full sun all daylight hours.
Would that still be working at breakeven and wouldn't you rather have
solar technology that wasn't so ancient and inefficient. And don't
forget storeage and converion costs. That equipment wears out too.
BTW, where's the bulk of your electricity being used for?
Conservation on that end makes more sense. Compact flourescents are
alreay affordable and acceptable and high efficiency LED lighting is on
the way. I'm sure LCD screens take less electricity than tubes.
As far as carbon footprint, I would think transportation is the 10
ton ape there too.
Best bang for the buck means PV takes a backseat for a while. Watch out
for BP, they have the interest and resources to push PV forward. I'd
like to know what their costs are.
If you want to do solar, solar heating makes a lot of sense... Cost
per KW of energy is at least an order of magnitude lower (than PV). For
home built it may be two orders of magnitude.