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Re: Controlling the solar scourge



Tom Gray  <tomgray@igc.apc.org> wrote:
>Nick Pine writes:
>>Steve Baer writes:
>>>   Another way to look at the money now spent on solar energy research
>>>   is that it is being used as a vaccination against the full blown disease
>>>   of solar energy utilization. A certain amount of solar energy activity
>>>   is encouraged so that the country can reach an actively immune state.
>>>   Those who own or control the competing energy sources--coal, oil, gas,
>>>   nuclear--can then become familiar with the threat--solar energy. Projects
>>>   can be undertaken that will result in failure or extraordinarily high
>>>   prices.
>
>Interesting theory, but it fails to explain why many of the most 
>ardent critics of solar R&D are conservative supporters of the fossil 
>and nuclear energy industries.

That seems natural to me. If you are against one thing, you tend to be
for an alternative. This is an old amorphous theory of Steve Baer's,
not mine. Perhaps you are talking about different, less subtle people (?)
Steve thought this was not an organized conspiracy, just what happens
when people chase money...  

On the other hand I can imagine some people at the Electric Power Research
Institute or Exxon might have sat down 20 years ago and said "Let's do a
study to debunk this solar thing," and gotten some people to come up with
the conclusions they had in mind at the beginning. To a certain extent,
they don't have to do that any more, because there are a lot of uneconomical 
or poorly-performing AE systems around now to look at. For instance, everyone
"knows" that passive solar houses are an expensive hobby, and they don't work
very well except in the Southwest US. And then there's my friend in New York
City who plans to cover his house with PV panels and fill it with batteries,
and Dennis Weaver's two million dollar collection of old tires. 

Even without this help, it seems to me that large existing infrastructures
and flows of money will do what they can to protect themselves, somehow,
against the widespread practical use of alternate energy.

>It also fails to explain why the government continues to fund fossil 
>and nuclear R&D.  Is this also a vaccination?  If so, why hasn't it worked?

I guess that's just pork barrel power: "Hey, we have jobs, we vote, we
want some of that money too." :-)

> >   I would expect many of the projects to be undertaken in the midst of
> >   huge government laboratories primarily devoted to other activities,
> >   such as nuclear energy. There the avid solar energy worker is likely
> >   to find himself transferred when he becomes too productive.
>
>But they aren't.  Federal renewable energy R&D is largely focused at 
>the National Renewable Energy Laboratory.  For further information, 
>visit their WWW site at <http://nrelinfo.nrel.gov>.

I visited NREL last month. It's changing. For instance, they are acquiring 
some combustion engineers. Their projects seem strangely impractical to me.
They seem more interested in high tech research than proliferation of high-
performance, cost-effective systems. Their solar data book and solar data
CDs are very nice, but their shiny new visitor's center has a Trombe wall,
invented in 1881...

A few years ago, I spent some time explaining to a local architect, a more
technical person than most, who had studied some engineering, that a "Trombe
wall" with some insulation on the outside and some passive plastic film
dampers to the inside of the house, that let air flow into the house during
the day, was probably a lot more efficient at collecting and keeping solar
heat in the house than a plain old "traditional" Trombe wall, with bare
masonry right behind the glass, with no insulation. Here's what I said:

  A "Trombe wall" with insulation on the outside, and 1 square foot of South-
  facing single-glazed area and an R-value of 20, will receive about 1000
  Btu/day of heat on an average 32F December day, where I live. If the room
  behind it has a constant temp of 70F, and the sun shines 6 hours a day,
  on the average, the energy that leaks out of the glass will be about 6 hours
  x (70F-32F) x 1 ft^2/R1 = 228 Btu during the day, and 18 hours x (70-32) x
  1 ft^2/R20 = 34 Btu at night, a net gain of 1000 -228 -34 = 738 Btu/day.
  Simple, no? (750 Btu, net, with double glazing, which passes less sun.)

  A standard unvented Trombe wall (Table IV-14b of Mazria's book says vented
  ones don't work much better) with a very large uninsulated thermal mass
  right behind the glass and an R-value of, say 2 (roughly 1' of masonry),
  would have an average temperature at the outside wall surface of about
  32F + R1 x (70F-32F)/(R2+R1) = 45F, if there were no sun. If you add a
  heatflow of 1000 Btu/day of sun to that model, falling on the outside
  of the wall, the outside wall surface will have an average temperature
  of about 45F + 1000/24 x (R=2/3) = 72.4F, which contributes 24 hours x
  (72.4F- 70F) x 1 ft^2/R2 = 29 Btu/day to the room behind the wall.

  So the "improved Trombe wall" above, (actually an air heater with the
  thermal storage inside the house) is more than 25 times as efficient
  (738/29) at collecting and keeping heat in the room behind it, than
  the usual Trombe wall. This is somewhat oversimplified, of course...

And do you know what the architect said? "I agree with you completely, but
if you do that, you will violate the integrity of the traditional Trombe wall,
which has a magical, wonderful way of *flywheeling*, and transporting the
heat through the wall, so it is available at the other side *precisely* when
it is needed, the next morning!" And he went on and on about this conceptual
delight, this conceit, completely ignoring numerical performance... :-)

Trombe walls are also thermal disasters during long strings of cloudy days.
When the sun goes in for a week or two, they lose their stored heat in less
than a day, and then leak house heat badly, dramatically raising backup
heat or other solar thermal storage requirements.

I'm still amazed that so many people, even in these newgroups, are still so
interested in Trombe walls, or their passive solar equivalents, like
high-thermal mass sunspaces. A lot of people are apparently still willing
to settle for high-cost, low-performance passive solar house heating
techniques, with 30% yearly savings in backup space heating costs over a
20 year payback period, compared to a conventional house, vs. houses with
warmstores, solar closets, sunspaces and transparent siding, which can
provide close to 100% of the space heating energy needed for the house AND
close to 100% of the hot water, with a 2 year payback period.

> >   It is certainly fortunate that a great deal of success is within reach
> >   of the backyard inventor and the small shop.
>
>Maybe for PVs (although I doubt it)

I do too. Seems like you need a million dollar semiconductor fabrication
facility to do interesting things with PVs. And even then, the PV products
will still be expensive. Of course the big price breakthroughs are just
around the corner :-) 

>not for wind. 

I'm not sure about that. If we had more wind in PA, I might be trying to do
some aerodynamic simulations on my PC, along the lines of the Polytech school
in Montreal, and doing VAWT experiments in my backyard, with an auto rear end
sitting under a double delta Darrieus configuration made with plastic coated
steel tubing, steel wires and dacron sailcloth. 

>For utility-scale wind,

I'm thinking more about 1-10 kW, or perhaps less power.
No tower. Matters of scale and centralization are important.

>the cost of bringing a new design to market is $millions, even in
>the private sector.

I believe that.

>For residential wind, systems are still too pricey for mass market success.

I like the Air 303. $550 for 375 watts, from Jade Mountain at (800) 442-1972.
Now all we need is a cheap, reliable synchronous inverter to feed this tiny
power back to the grid. I'm an electrical engineer. I keep telling people
that a synchronous inverter at this power level should not cost much more
than a lamp dimmer. A simple triac bridge, a backwards lamp dimmer, with a
small microprocessor to determine the optimum load for the windmill, $10
worth of parts. Someday, someone will design one of these. This is not a
very difficult job for the right kind of electrical engineer. Perhaps there
is a German product like this already. 

>Bringing their costs down through advanced
>manufacturing technologies is, again, a high-stakes game. 

I think the Air 303 people are investing lately in molds to bring down
the price even more. This is pretty straightforward, not a very risky game,
and the stakes are not all that high, compared to the sales figures. It
seems very unlikely that NREL would ever do something like this. 

Nick


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