Posted by Anthony Matonak on January 27, 2008, 12:19 pm
J. Clarke wrote:
So? Why should any one technology or energy source do it all?
If it's useful for some things then it's good enough to be used
for those things.
There is plenty of surface area on the Earth so that's not an issue.
If I recall correctly, we would only need to harvest a fraction of
a percent of the suns energy that falls on the land area of the planet
to supply all the energy needs of our civilization.
Actually, most people consider them distinctly different sources
of energy. If you want to go far enough back everything is powered
by the big bang but no one really talks like that in real life.
In how many areas does geothermal have to work? It's not like it
has to be the one single energy source for the entire world. If
it works in some areas then it works for those areas.
Why mess with it if there are less expensive, less dangerous and less
controversial alternatives? Even two out of three wouldn't be bad.
Sure, replace a patch of partially reflective soil with something
black and the area will warm up. We do this with roads, roofs and
parking lots and it generates a heat island effect. Even then, the
effect isn't significant enough to affect global temperatures.
In the United States, we've actually paved and built over more area
than would be required to supply all the energy demands of the country
with solar PV. Covering a black parking lot with black solar collectors
won't make any noticeable difference in temperatures.
Yes. This is a fact you can find with a quick web search.
The search is hardly required. I can remember when PV was more than
$/Watt and it can now be purchased for $/Watt. One company says
they are shipping panels for $/Watt (but not to just anyone).
Going from $ to $ to $ is my definition of "getting cheaper". :)
Posted by J. Clarke on January 27, 2008, 3:19 pm
Anthony Matonak wrote:
Well, when I run the numbers it works out to 1.6 percent after you
factor out forest and farm land and correct for albedo and the
inefficiency of collectors and consider that you have to double since
only half or less of that land area gets sunlight at any given time.
There's also an air mass calculation that's more involved than I want
to get into for a typical worthless USENET debate. I really need to
factor out land in the arctic and antarctic (no matter how you try to
sugarcoat it when you have months with no sun solar isn't practical)
but I'm too lazy to find those numbers. But figuring land area is
grossly oversimplifying the issue.
Consider them "different" all you want to, the all come out of the
It has to work in enough areas to make it economically justifiable to
develop the technology for doing it.
What alternative is less expensive? Solar? Show me the numbers. As
for "less controversial", that's politics, not technology.
Seems to me that a lot of people have been saying that about CO2.
Except that parking lots don't stay black. The reflectance of worn
asphalt is greater than that of pine forest. The reflectance of new
concrete is higher than that of most natural surfaces.
If they aren't shipping to "just anyone" at that price then they're
subsidizing it with something else.
Well that's good news. In a few more decades maybe it will be cheaper
to build a solar plant than coal or oil or nuclear. So what's the big
deal? When that happens then the utilities will start building solar.
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)
Posted by Steve O'Hara-Smith on January 27, 2008, 5:55 pm
On Sun, 27 Jan 2008 10:19:51 -0500
Nope the $/Watt outfit is Nanosolar who have a roll to roll
printing system for producing PV sheets. Their stated reason for not
shipping to "just anyone" is that they have their first 12 months
production already sold to utility scale buyers. As far as I can make out
if you want to buy from them you must be prepared to buy a lot and to wait
at least 12 months.
Er utilities have started building solar as well as wind systems.
Oh yes - I don't think direct solar will ever carry the baseload -
the only direct solar system I think could would be SPS and that is at the
very best an extremely high investment solution that almost certainly
requires about two orders of magnitude cheaper cost to orbit than is
currently available to make it pay. If you think that puts it out of the
picture for the foreseeable future I would not argue.
OTOH direct solar thermal can reduce the load on centrally
generated power and that is IMHO worthwhile.
C:>WIN | Directable Mirror Arrays
The computer obeys and wins. | A better way to focus the sun
You lose and Bill collects. | licences available see
Posted by Mauried on January 27, 2008, 9:57 pm
On Sun, 27 Jan 2008 17:55:21 +0000, Steve O'Hara-Smith
Nowhere have I seen any evidence that Nanosolar are actually selling
their solar panels for $ a watt.
All they have stated is that they can make them for $ a watt and that
they are sold out for the next 18 months.
The actual shipping price has not been revealed.
The manufacturing cost of a product does NOT equal its sale price.
Posted by Mauried on January 27, 2008, 10:04 pm
On Sun, 27 Jan 2008 21:57:12 GMT, email@example.com (Mauried) wrote:
But heres an interesting question to consider.
Whats the exit electricity price from a Solar power station thats
replacing a 1 GW base Load Coal fired plant even if solar cells are
Include the costs of how you make the power at night, how you store it
, the costs of your 1 GW Inverter, etc.
Still a lot of money.