"Jim Thompson" wrote in message
...

While you are dicking around with solar cells the big
power companies will build a solar-powered steam plant with *huge*
servo'd mirrors. I put pencil-to-paper once upon a time... you can do
marvelously if you've got the acreage.


They already have.

http://www.volker-quaschning.de/downloads/VGB2001.pdf

Scroll down to page 5.

On Tue, 20 Apr 2004 10:14:31 -0700, "Richard Henry"
wrote:


"Jim Thompson" wrote in message
.. .

While you are dicking around with solar cells the big
power companies will build a solar-powered steam plant with *huge*
servo'd mirrors. I put pencil-to-paper once upon a time... you can do
marvelously if you've got the acreage.


They already have.

http://www.volker-quaschning.de/downloads/VGB2001.pdf

Scroll down to page 5.


Arizona Public Service has a similar operating facility west of
Phoenix that, for some reason, is kept very hush-hush. It was in the
papers a few years ago, then no more mention.

The efficiency of such a system FAR exceeds what will EVER be attained
with photo cells.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

On Tue, 20 Apr 2004 10:14:31 -0700, "Richard Henry"
wrote:


"Jim Thompson" wrote in message
.. .

While you are dicking around with solar cells the big
power companies will build a solar-powered steam plant with *huge*
servo'd mirrors. I put pencil-to-paper once upon a time... you can do
marvelously if you've got the acreage.


They already have.

http://www.volker-quaschning.de/downloads/VGB2001.pdf

Scroll down to page 5.


Arizona Public Service has a similar operating facility west of
Phoenix that, for some reason, is kept very hush-hush. It was in the
papers a few years ago, then no more mention.

The efficiency of such a system FAR exceeds what will EVER be attained
with photo cells.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

"Anthony Matonak" wrote in message
...
....
I don't know about that. Solar PV can be used in any size from digital
watches to powering hotels. Big power companies have to buy the same
parts as individuals and would mostly pay similar prices. The large
infrastructure to build and maintain them is called "the rest of
civilization" for the most part and is accessible for an individual
as it is for a big power company.

So, first you have to build and support a huge civilization, not stand alone
as an individual. Big point that. The power company would buy in really
large blocks, install in a single area without pre-existing structures in
the way. I would be surprised if their PV installed cost were (assuming they
are in this for profit not subsidies) any more than a third what the
individual must suffer. Of course a skilled do it yourselfer with time to
hunt up bargains might do a lot better, but this has to apply to the whole
people, not just the few.

....
Oddly enough, many people do live where the sunlight is fairly reliable
and a PV system can be small enough to be practical for an individual.
The civilization as a whole is just a collection of individuals when
you look at it closely enough.

I am not saying that an individual cannot spend an arm and a leg, buy a
system that is three times the size of an optimized well sited system,
overwhelm everything with massive and expensive battery storage, and be
perfectly happy with running out of power in the middle of microwaving his
hot dogs, but you gotta recognize that overall this process needs to be made
as inexpensive as possible or it will make most of us a lot poorer. I am
concerned that you are seeing that a PV system can be built, but not what
the trade offs of this system imply to our lives. I believe that when PV
electricity becomes cheaper than coal/natural gas/uranium, (if it can), then
most of us will be buying most of our electricity from huge PV arrays in the
southern deserts, not from a little farm outside our town. There will be few
who will "roll their own", and some small town back up plants for summer
peaks and such, but the bulk power has to be the cheap power and that has to
be large and in the right place to make solar power.

....
Grid tied systems need close to zero maintenance so I hardly see that as
giving constant headaches. Even with a battery system, I've heard about
some that only require a checkup every six months or so. Lastly, while
PV may be more expensive than grid power, I don't think that a big power
company can build solar PV all that much cheaper than anyone else.

Grid tie is great for a small system or two. If we get more than 20% from
such systems, the grid has to be redesigned to be a storage system of sorts.
I overstated what I think is the actual level of difficulty to get you to
think about the demand you are making on the ordinary citizen to maintain
his private power system. Every few years he has something break down, and
he knows nothing about it. The maintenance costs eat his profit for dinner.
A tree branch, an ice storm, a battery failure, a lightening bolt, and his
system is disconnected from the grid so he can turn his lights on, and we
are back to the centralized distributions system. Your last point, that you
think a big company can not build PV much cheaper than Joe, and the general
implication that the cost to Joe of electricity from his local PV system is
competitive with ConEd from the Mohave Desert by way of the grid, needs a
lot more quantification I think. As I recall there is around a 3 to 1
difference in the average solar insolation between Seattle and Phoenix, for
example. It is pretty hard to make up for that kind of a cost differential,
but on top of that you have to add even more storage someplace for all that
electricity, since the winter insolation up here is really crappy for months
on end. That is one heck of a lot of storage, and to do it locally is
generally from hard to impossible. (In Seattle we might be able to find a
nearby mountain valley we could turn into a lake for hydrostorage, but a lot
of locations are a long ways from any possible storage site). .

"Anthony Matonak" wrote in message
...
....
I don't know about that. Solar PV can be used in any size from digital
watches to powering hotels. Big power companies have to buy the same
parts as individuals and would mostly pay similar prices. The large
infrastructure to build and maintain them is called "the rest of
civilization" for the most part and is accessible for an individual
as it is for a big power company.

So, first you have to build and support a huge civilization, not stand alone
as an individual. Big point that. The power company would buy in really
large blocks, install in a single area without pre-existing structures in
the way. I would be surprised if their PV installed cost were (assuming they
are in this for profit not subsidies) any more than a third what the
individual must suffer. Of course a skilled do it yourselfer with time to
hunt up bargains might do a lot better, but this has to apply to the whole
people, not just the few.

....
Oddly enough, many people do live where the sunlight is fairly reliable
and a PV system can be small enough to be practical for an individual.
The civilization as a whole is just a collection of individuals when
you look at it closely enough.

I am not saying that an individual cannot spend an arm and a leg, buy a
system that is three times the size of an optimized well sited system,
overwhelm everything with massive and expensive battery storage, and be
perfectly happy with running out of power in the middle of microwaving his
hot dogs, but you gotta recognize that overall this process needs to be made
as inexpensive as possible or it will make most of us a lot poorer. I am
concerned that you are seeing that a PV system can be built, but not what
the trade offs of this system imply to our lives. I believe that when PV
electricity becomes cheaper than coal/natural gas/uranium, (if it can), then
most of us will be buying most of our electricity from huge PV arrays in the
southern deserts, not from a little farm outside our town. There will be few
who will "roll their own", and some small town back up plants for summer
peaks and such, but the bulk power has to be the cheap power and that has to
be large and in the right place to make solar power.

....
Grid tied systems need close to zero maintenance so I hardly see that as
giving constant headaches. Even with a battery system, I've heard about
some that only require a checkup every six months or so. Lastly, while
PV may be more expensive than grid power, I don't think that a big power
company can build solar PV all that much cheaper than anyone else.

Grid tie is great for a small system or two. If we get more than 20% from
such systems, the grid has to be redesigned to be a storage system of sorts.
I overstated what I think is the actual level of difficulty to get you to
think about the demand you are making on the ordinary citizen to maintain
his private power system. Every few years he has something break down, and
he knows nothing about it. The maintenance costs eat his profit for dinner.
A tree branch, an ice storm, a battery failure, a lightening bolt, and his
system is disconnected from the grid so he can turn his lights on, and we
are back to the centralized distributions system. Your last point, that you
think a big company can not build PV much cheaper than Joe, and the general
implication that the cost to Joe of electricity from his local PV system is
competitive with ConEd from the Mohave Desert by way of the grid, needs a
lot more quantification I think. As I recall there is around a 3 to 1
difference in the average solar insolation between Seattle and Phoenix, for
example. It is pretty hard to make up for that kind of a cost differential,
but on top of that you have to add even more storage someplace for all that
electricity, since the winter insolation up here is really crappy for months
on end. That is one heck of a lot of storage, and to do it locally is
generally from hard to impossible. (In Seattle we might be able to find a
nearby mountain valley we could turn into a lake for hydrostorage, but a lot
of locations are a long ways from any possible storage site). .

"Roger Gt" wrote in message
. com...

Manhattan Island was "Bought" for $24.00 worth of beads, from
Indians who thought it strange that anyone would ask to "Buy"
anything, but they took the beads!

The fact that the colonists were willing to pay anything of value implies
that they ecognized the origianl inhabitants claim to the land


The only thing Indians "Owned" was a franchise to build Casinos!!!

I have some questions about your history books: How many pictures are on
each page? 1, 4, or 8? Are they precolored, or do you have to use your
crayons? Is some of the text in balloons or is it all in the captions?

"Roger Gt" wrote in message
. com...

Manhattan Island was "Bought" for $24.00 worth of beads, from
Indians who thought it strange that anyone would ask to "Buy"
anything, but they took the beads!

The fact that the colonists were willing to pay anything of value implies
that they ecognized the origianl inhabitants claim to the land


The only thing Indians "Owned" was a franchise to build Casinos!!!

I have some questions about your history books: How many pictures are on
each page? 1, 4, or 8? Are they precolored, or do you have to use your
crayons? Is some of the text in balloons or is it all in the captions?

"Jim Thompson" wrote in message
...
....
The efficiency of such a system FAR exceeds what will EVER be attained
with photo cells.

I won't take that without a bit of study. The solar cells take a scads of
energy to build, but once built run for a very long time without much
maintenance. The thermal system is mechanically more complex, requires a lot
more maintenance, is more sensitive to wind loading, and of course you are
running pretty cool so the thermal efficiency is not all that great. I would
think the solar trough is more like 20% and probably much closer to PV than
you allude. The very large focusing arrays can run a lot hotter, and may
then give you a bit better efficiency, but you are still not likely to make
much over 40% and even at that, if you add in the higher rates of "dead"
space that the big focusing arrays use, you may find the total percentage of
energy recovered per square mile to be under 20%. The cost per KWH recovered
is, I think, the killer here, and the increased maintenance adds a lot to
this cost for the thermal array.

"Jim Thompson" wrote in message
...
....
The efficiency of such a system FAR exceeds what will EVER be attained
with photo cells.

I won't take that without a bit of study. The solar cells take a scads of
energy to build, but once built run for a very long time without much
maintenance. The thermal system is mechanically more complex, requires a lot
more maintenance, is more sensitive to wind loading, and of course you are
running pretty cool so the thermal efficiency is not all that great. I would
think the solar trough is more like 20% and probably much closer to PV than
you allude. The very large focusing arrays can run a lot hotter, and may
then give you a bit better efficiency, but you are still not likely to make
much over 40% and even at that, if you add in the higher rates of "dead"
space that the big focusing arrays use, you may find the total percentage of
energy recovered per square mile to be under 20%. The cost per KWH recovered
is, I think, the killer here, and the increased maintenance adds a lot to
this cost for the thermal array.

Roger Gt wrote:
The Indians would war on their Neighbors for anything they wanted.
Kill anyone who resisted and sell prisoners into slavery.

Thanks, I wondered where the USA learnt to do that.
Made a fine art of it now, haven't they?