Dr. Geoffrey Landis has just published an excellent review of the
economics of PV and how it relates to terrestrial and space based
power generation markets.

http://gltrs.grc.nasa.gov/cgi-bin/GLTRS/browse.pl?2004/TM-2004-
212743.html

Landis analyzes the economics, noting that SPS power can be sold into
different markets at different times of the day as the demand curve
changes, by selective beaming.

My comment: Terrestrial PV are limited to daylight with relatively
clear skies, unless expnsive storage systems are used, or very long
distance grid transmission is employed (also expensive).

Some quotes from the Landis paper:

Synergy With Terrestrial Solar

Space and Ground Solar Power
Analyses of space solar power often assume that ground solar power is
a competing technology, and show that space solar power is a
preferable technology on a rate of return basis. In fact, however,
space solar power and ground solar power are complementary
technologies, not competing technologies. These considerations were
initially discussed in 1990 [4]. Low-cost ground solar power is a
necessary precursor to space solar power: Space solar power requires
low cost, high production and high efficiency solar arrays, and these
technologies will make ground solar attractive for many markets. The
ground solar power market, in turn, will serve develop technology and
the high-volume production readiness for space solar power.

Since ground solar is a necessary precursor to space solar power, an
analysis of space solar power should consider how it interfaces with
the ground-based solar infrastructure that will be developing on a
faster scale than the space infrastructure. Some possible ways that
this interface could be optimized
include:

1. Integrate solar and microwave receivers on ground. This will allow
the space solar power to use the pre-existing land that has already
been amortized by ground solar power receivers, and tie in to power
conditioning and distribution networks that are already in place.

2. Use solar power satellites to beam to receivers when ground solar
is unavailable. By "filling in" power when ground solar is
unavailable, space solar power will serve as the complement to solar.

Thanks for the link -- I'm dowloading the PDF now (wish people would
just use HTML!). I'll need to read it to see if he just assumes ground
PV will be in big facilities linked into the grid or analyzes gridless
local use without grid delivery costs vs. gridded SPS operations for
expected costs in a couple decades. It is interesting to see in the
excerpt you quote a sense that ground based solar will definitely
preceed SSPS -- it's just a matter of whether SSPS than proves
advantageous over what much improved ground PV delivers (capital cost
and storage cost and construction pollution being major potential areas
of benefit for SSPS -- yet facing a huge cost to get started with SSPS
and also facing distribution costs and other costs from grid maintenance
and security etc.).

Update: Oops -- just finished downloading it and it won't run in the
Ghostscript PDF display system under GNU/Linux. Wish NASA would try to
make its works more accesible by just putting them in text files or HTML
or OpenOffice or RTF! (The PDF "standard" even through in a book is
complex and sometimes ambiguous and only the proprietary implementations
from Adobe really define it... As Alan Kay said, any written standard of
more than threee lines is ambiguous -- why we need standards defined by
free implimentations.) Well, I'll poke around some more and see whether
something else can read it or if it just maybe was a corrupt download.

--Paul Fernhout

> Update: Oops -- just finished downloading it and it won't run in the
> Ghostscript PDF display system under GNU/Linux.

Well, I downloaded it again and it still didn't open properly (and both
files are different sizes!) but I remembered the by submitting my
interests and loosing privacy to Adobe they will convert it on their web
site to HTML, so it seems to be working there:
http://www.adobe.com/products/acrobat/access_simple_form.html
(although the figures get messed up).

A couple basic flaws in its analysis:

* while it is true that demand for electric power varies over time NOW
such as in the article looking at New York City power use, that is given
the current infrastrucutre and industrial use. If we generated hydrogen
or synthetic fules from electricity, then demand curves could be more
easily adjusted to supply, as production of hydrogen or liquid fuels (or
other energy intenseive processes like aluminum production) could
smoothly match changes in demand so all the power was used more
effectively. IMHO that change in use assumption undermines a major
premise of the paper for makign SPS more cost effective.

While the grid is not discussed, the paper does refer to a case for high
price power delivery where "... distribution system is doubled. This
trade-off is only reasonable if the ground infrastructure cost is not
the major fraction of the power cost." So, I think this paper has
already made a fundamentally bad assumption at least as far as
residnetial power judging from my electric bill (almost half the cost
beign for "delivery").

Also, the paper for example "Figure 6 compares the power required for
New York with the power produced by a fixed solar plant designed to
supply power during this daytime peak." So in an effort to compaer
apples to organes, it turns the potentially distributed non-delivery
cost ground based solar apple to a centralized grid-dependent
high-delivery cost orange.

Anyway, I may not be doing the paper justice as I can't properly see the
tables and am just skimming it for first impressions at this point. But
at first glance it seems to me it is not seriously addressing grid
issues, security, and distribution costs. Becuase I had trouble readign
the tables -- does it even produce a firm cost for delivered electricity?

--Paul Fernhout

Thanks for the link -- I'm dowloading the PDF now (wish people would
just use HTML!). I'll need to read it to see if he just assumes ground
PV will be in big facilities linked into the grid or analyzes gridless
local use without grid delivery costs vs. gridded SPS operations for
expected costs in a couple decades. I think you'll find it's the former. In fact, one of the points Geoffrey makes is that it's conceivable one might design a dual-use rectenna/PV array that might generate power from sunlight during the day, and from microwaves during the night. As long as the land is set aside for power reception, might as well maximize the real-estate investment. But the major point seems to be that ground-based and SPS are complementary, not competitors. And he's big on matching electrical usage curves, and on SPS designs that get by without power busses.

Regards,
Mike Combs

assumes
> ground
> PV will be in big facilities linked into the grid or analyzes
> gridless
> local use without grid delivery costs vs. gridded SPS

Gridless local use is uneconomic. The cost of storage is
prohibitive, and the collateral damage of batteries becomes a social
problem.

Storage batteries have limited life, need to be replaced every couple
of years.

I have yet to have a NiCd battery in my home last more than a matter
of months before it basically becomes useless (only holds charge for
about 10 - 20 minutes). My personal experience over 10+ years, and
many batteries.

Most gridless PV systems today use bulky lead-acid batteries, major
disposal problem. Can be recycled, at a cost.

> Gridless local use is uneconomic. The cost of storage is
> prohibitive, and the collateral damage of batteries becomes a
> social problem
> Storage batteries have limited life, need to be replaced every
couple of years.

> I have yet to have a NiCd battery in my home last more than a
matter of months before it basically becomes useless (only holds
charge for about 10 - 20 minutes). My personal experience over 10+
years, and many batteries.

> Most gridless PV systems today use bulky lead-acid batteries, major
> disposal problem. Can be recycled, at a cost.

Charles--
Pretty 20th-century thinking, there...don't you think?(!)

Seriously-- I think there are two points to be made here:
1. we can call agree that 'robust' means anything and everything--even
distributed sources that aren't too far afield-- is also linked
(properly) to the grid. So that's not at issue.

2. Where you're overly-pessimistic, I think, is in energy storage.
Batteries are 'bad'-- which is why so much money is going into ways to
get around them. One of the leading customer industries here is
telecom (or anyone with remote towers, relays, et al); where not only
are batteries expensive, heavy, environmentally-unsound, and even
dangerous...but they also get stolen a lot more often than we hear
about.

The following technologies each have multiple companies not only
working on them, but with 'beta' units running at customer sites,
right now:

a. flywheels-- flywheels as local temporary storage devices are
increasing sales of late; since they not only don't have safety,
environmental, etc. problems of batteries, but they are much more
reliable, with Active Power (for one) basically claiming a 20-year 'al
most maintenance free life'. Their main--but not only-- sales line is
as an adjunct to Caterpillar for backup or UPSs, where the flywheel
picks up the load for seconds (up to 15 minutes is what they are
working on) while the bigger genset comes online.
While not cheap enough for 'home' use yet, they may in fact get there;
and while a flywheel may only provides seconds or minutes of power for
a facility, they theoretically can do much more for a house or
something.

b. Hydrogen-- storing energy as hydrogen is being actively worked on
by many right now. Leading companies in this arena include Distributed
Energy, Honda, Stuart Energy, Hydrogenics, Plug Power---plus many
others in Europe and Japan. Several of these have active programs that
have (relatively small) windmills providing primary power...and
storing energy as hydrogen, which, when needed, gets used by a fuel
cell. Several others are doing the same thing, with solar as the
primary energy source, part of which generates hydrogen for use when
needed. Some are actively doing both (e.g., Distributed Energy).
There's one facility in Germany running that way now; the Navy just
issued a contract to do so at one of its facilities; and Norway now
has its first island community (only 10 homes, but its a start) where
one of these setups is the real power for the people on the island.

Also: Stuart Energy and Shell; Plug Power and Honda....are working on
home systems that not only store energy as hydrogen, but also use it
to fuel up a hydrogen-powered internal combustion or fuel cell car.
(Honda is already doing this with natural gas, by the way; you can
order a natural gas Civic retail now, and in the $21,000 price comes a
home filling station--made by a small Canadian company, who has
nicknamed its product 'Phil'-- that mounts on the wall in your garage,
is plugged into your home gas line, and your car fuels up from that
overnight...at a much cheaper cost than gasoline for a Civic). Going
the next step to doing something similar with hydrogen is not only
Honda's plan...but they already have one such test setup, powered by
solar, up and running in L.A.; and have partnered with Plug to get
more serious.

Bottom line is, a ton of work, world-wide, is going into getting rid
of batteries and finding better/safer/greener/more robust energy
storage, for whole hosts of reasons. There will be many, usually
remote, applications, that will never be tied into a grid...but yet
can still be 'economic' by replacing batteries with different, more
modern setups

(full disclosure: this is an investment-area of interest for me, and I
have stock in some of the companies above).

Cheers,

Dave Huntsman

--- In ssi_list@... "Dave Huntsman"

Hi Dave,

From the tenure of your response I'm assuming you weren't a member
of this list in December when Paul and I went head to head on
terrestrial solar, distributed power, storage issues, etc.

If you have the patience and want a wealth of data from both sides
of the issue you can start reading through the archives at this post
(which seems to have started the debate and it evolved from there:

> 2. Where you're overly-pessimistic, I think, is in energy storage.

Actually, Charles is being quite realistic. Storage is the achilles
heel of "green power" and I think even Paul recognizes the serious
issues here.

> a. flywheels-- While not cheap enough for 'home' use yet, they may
> in fact get there; and while a flywheel may only provides seconds
> or minutes of power for a facility, they theoretically can do much
> more for a house or something.

No they can't. The issue they have to contend with is energy
density, and they simply don't measure up.

> b. Hydrogen--

Huge problems here. I urge you to go back to the December archives
and work your way through them. Pretty soon you'll get to the meat
of the debate between Paul and myself where hydrogen is looked at in
detail. Lot's of insurmountable problems are addressed.

> (full disclosure: this is an investment-area of interest for me,
> and I have stock in some of the companies above).

Good luck. I hope your sense of market timing is better than those
who held internet stocks. You'll make money as long as the companies
stay small, there are other buyers who will buy your stock based on
hype. Once the technology is looked at seriously for grid or oil
replacement then the shortcomings will become evident to a larger
audience of investors. I hope you're out of the stocks at that
point :)

TangoMan

> I have yet to have a NiCd battery in my home last more than a matter
> of months before it basically becomes useless (only holds charge for
> about 10 - 20 minutes). My personal experience over 10+ years, and
> many batteries.

NiCd batteries have lots of problems -- but the guy (Stan Ovshinsky) who
invented amorphous semiconductors for use in among other things
continuous thin-film solar cell production also went on to do work on
NiMH batteries (and is now onto solar hydrogen and other things), and
from what I read these NiMH batteries do not seem to have the same
memory effect. (They may have other issues, including cost.) His
company: http://www.ovonic.com/

There are also things called ultracapacitors -- but I don't know much
details on them.

--Paul Fernhout

So Paul, you seem at last to agree with me one one point, that there
are no cost-effective mass-produced rechargeable batteries on the
market.

Requirements for a rechargable battery type for gridless power are:

- cheap
- safe
- non-toxic
- reliable
- long life
- no memory fade

I cannot think of any battery type known to mankind which meets ALL
of those requirements, and I have done some work in the field. There
are some batteries which meet some of those requirements, but that
does not cut it.

Until somebody develops a battery which meets ALL of those
requirements, gridless power remains a dream.

Can we therefore finally table further discussion of gridless power
in this forum.

Best regards,

Charles F. Radley

--- In ssi_list@... "Paul D. Fernhout"
> > I have yet to have a NiCd battery in my home last more than a
matter
> > of months before it basically becomes useless (only holds charge
for
> > about 10 - 20 minutes). My personal experience over 10+ years,
and
> > many batteries.
>
> NiCd batteries have lots of problems -- but the guy (Stan
Ovshinsky) who
> invented amorphous semiconductors for use in among other things
> continuous thin-film solar cell production also went on to do work
on
> NiMH batteries (and is now onto solar hydrogen and other things),
and
> from what I read these NiMH batteries do not seem to have the same
> memory effect. (They may have other issues, including cost.) His
> company: http://www.ovonic.com/
>
> There are also things called ultracapacitors -- but I don't know
much

--- In ssi_list@... "Charles F. Radley"
>
> So Paul, you seem at last to agree with me one one point, that
there
> are no cost-effective mass-produced rechargeable batteries on the
> market.
>
> Requirements for a rechargable battery type for gridless power are:
>
> - cheap
> - safe
> - non-toxic
> - reliable
> - long life
> - no memory fade
>
> I cannot think of any battery type known to mankind which meets
ALL
> of those requirements, and I have done some work in the field.

Flywheels

Ed,

Apparently you missed this response from Tangoman. Flywheels do not
cut it for the reasons given below. They just don't work, so they
fail to meet the requirement of "cheap".

Gridless power is dead Jim, let's forget about it.

Best regards,

Charles F. Radley

> a. flywheels-- While not cheap enough for 'home' use yet, they may
> in fact get there; and while a flywheel may only provides seconds
> or minutes of power for a facility, they theoretically can do much
> more for a house or something.

No they can't. The issue they have to contend with is energy
density, and they simply don't measure up.

> So Paul, you seem at last to agree with me one one point, that there
> are no cost-effective mass-produced rechargeable batteries on the
> market.

The issue is more complex than yes/no. There are a variety of economic
niches and a variety of technologies to fill them given today's
(tax-wise distorted) economic landscape. Some choices are very cost
effective today -- for example on a recent local trip past construction
the only portable roadway move over arrow signs were solar powered
(versus the older generator ones). Success in some of these drives
towards future success in others.

Also, if the true social, environmental, and economic cost of nuclear
and fossil fuels and the grid and pipelines etc. (including defense
costs) was paid directly by the end user, those sources would cost the
equivalent of upwards of $200 per barrel of oil or more, and local solar
of various types along with battery recycling and cogeneration would be
the preferrred economic choice right now, warts and all.

> Requirements for a rechargable battery type for gridless power are:
>
> - cheap
> - safe
> - non-toxic
> - reliable
> - long life
> - no memory fade
>
> I cannot think of any battery type known to mankind which meets ALL
> of those requirements, and I have done some work in the field. There
> are some batteries which meet some of those requirements, but that
> does not cut it.
>
> Until somebody develops a battery which meets ALL of those
> requirements, gridless power remains a dream.

Then why are millions of people now using gridless power cost
effectively even now? Just take a look at a recent issue of homepower
magazine for example. Or look at the toronto house link.

> Can we therefore finally table further discussion of gridless power
> in this forum.

For the sake of argument (not that I agree), assume you were 100% right
that gridless power was a dream right now and no one used it (a
factually inaccurate position, but let's work from it). Even then, you
are making a sweeping assumption such technology would not prevail
economically from technological advances over the next thirty years it
would take to get an O'Neill style large SSPs venture going. So you
would be making a bet. Accept that you are proposing a gamble, and we at
least have the basis for continued discussion.

--Paul Fernhout

--- In ssi_list@... "Paul D. Fernhout"
> For the sake of argument (not that I agree), assume you were 100%
right
> that gridless power was a dream right now and no one used it (a
> factually inaccurate position, but let's work from it). Even then,
you

===========

To clarify, gridless power will be confined to small niche remote or
rural markets, it will not be a source of power for the majority of
humans, who are overwhelmingly urban dwellers.

===========

> are making a sweeping assumption such technology would not prevail
> economically from technological advances over the next thirty years
it

===========

Gridless power was proposed over thirty years ago, and thirty years
on, we are no closer. Of course you could say the same thing about
SPS, and nuclear fusion for that matter.

What will happen over the next thirty years, who knows.

But I do know this: all the necessary technology is available today
for SPS, it is not available for gridless power.

Gridless power requires breakthroughs in technology, SPS does not.

That is the essense of my thesis.

===========

> would take to get an O'Neill style large SSPs venture going. So you
> would be making a bet. Accept that you are proposing a gamble, and
we at
> least have the basis for continued discussion.
>
> --Paul Fernhout

===========

I do not understand that final paragrpah.

Cheers,

Charles R.