[Prev][Next][Index][Thread]
Re: solar water heater sources
Hla Tin <genotech@hooked.net> wrote:
>If anybody knows the sources for 50 gallon solar water heaters
>please let me know. I have a need for these for a developing country.
>I am located in California and would prefer a Calif. source.
How about combining PV and water heating?
.
clear corrugated . i T i .
polycarbonate--> . . .
. . <--PV panel .
. . .
In other words, use 4' x 12' Dynaglas polycarbonate "shingles" from SPS in
San Jose, CA (408) 997-6100 or Replex (800) 726-5151 for the roof with
Stanford Ovshinsky's new 5%-efficiency "PV shingles" in long strips UNDER the
rafters, and put some insulation up in the ridge peak, with an 8' long x 6"
diameter galvanized steel or PVC pipe water tank up there under the insulation,
with no insulation underneath the tank, so the tank is heated by solar hot air
>from the shingle-PV cavity, or say, 2 GPM of water trickling over the 6 m^2 (?)
of PVs, collecting in a small gutter and being pumped back up to the tank,
with a tiny PV-powered pump, when the tank water temp is low, with some sort
of damper with a bimetallic spring that opens near the top of the cavity to
let the PVs run cooler, when the tank is warm enough, eg the $11 AFV-1B
automatic foundation vent made by Leslie-Locke of Atlanta (gee, what a run-on
sentence :-)
Except for the PV part, this is cheaper than conventional roof construction,
and in a cold climate, it could provide daylighting and space heat for the
house beneath, if a reflective motorized return air damper in the insulated
attic floor, hinged on the north side, tilted up to the south and a fan blew
air down from the attic peak through one of the PV cavities, in sunny times.
Ovshinsky shingles are made in California, and make about 50 w/m^2 in peak sun
at 25 C, according to engineer Jim Young at United Solar (800) 397-2083, who
says this only decreases to 45 w/m^2 at 60 C. He says the current retail price
of their least expensive product is about $4.50/peak watt.
Nick
PS: I would guess these shingles won't get cheaper quickly, from this email
dialog with Villanova University's Professor Singh, posted with permission.
Date: Fri, 29 Mar 1996 10:08:16 -0500
To: nick@ece.vill.edu (Nick Pine)
From: "Dr. P. Singh" <singh@ece.vill.edu>
Subject: Re: inexpensive PVs...
Nick:
I am glad to see that you are getting some opportunities to contribute
to a few solar home designs. I have still not found a student group to work
on the solar shed - as soon as I do we'll follow up on that project.
>He didn't mention that it was that complex, and I'd gotten the impression
>somehow that the substrate was ordinary cheap mild steel...
Ovshinsky's panels used to use a Japanese steel because they could
not find an American steel manufacturer that made steel with a smooth enough
morphology to make good devices !! The process is complicated because the
amorphous silicon needs to have a low enough density of impurities and
defects in order to make devices. The amorphous silicon solar panels
actually start off as 8-10% efficiency and drop down to 5% because of
optical generation of defects in the amorphous silicon material. In
research, non-degraded 10% amorphous silicon cells have been demonstrated
but I don't think that they have reached production yet.
It is actually quite difficult to make solar cells that are 10%
efficient - especially over large areas. Imagine making square feet of solar
panels that are low in defects and impurities - it's not easy !!
The only company electrodepositing solar panels is BP Solar in
England. I'm not sure of the status of their production.
I hope that this information is useful to help you understand a
little more about PV processing. Please feel free to disseminate this
information to whomever you wish - but I would like you to mention me as the
source in case others wish to contact me for more information (especially on
my research work).
Hope we see some Sun again soon - it's quite dreary outside today.
Pali
At 04:08 PM 3/28/96 -0500, you wrote:
Hi Pali,
> I have a couple of corrections to make to your statements about my
>PV research and Ovshinsky's panels.
Thank you.
>I am working on electroplated solar cells on transparent substrates.
Sorry, I guess I missed that when you explained to me what you were doing.
>The electroplating process is a low temperature process (60 C) and so could
>potentially be used on plastic substrates with a transparent conducting
>oxide (such as tin oxide or indium tin oxide) as the transparent contact.
>This would allow potentially low cost devices to be manufactured since the
>process and materials costs could both be very low. The transparent substrate
>would also allow heat to pass through so that the use of these devices in
>a hybrid electrical/thermal system would be a great idea. It also makes
>a lot of sense to use these types of PV cells in a hybrid solar collector
>with a heat exchanger because that would allow the cells to operate a
>little more efficiently !!
I do recall your mentioning that a little company in Maryland was actually
producing these... Ovshinsky PVs make 50 w/m^2 in peak sun at 20 C, and 45 w
at 60 C. I wonder about the efficiency of your plated cells might be at
40-60 C, ie water heating temps... Or will that damage them?
In Ovshinsky's case, the PVs would absorb 90% of the sun as heat, which might
heat air or water directly, but in your case, I guess that 90% would shine on
through the cell to strike a dark surface, perhaps behind another transparent
layer with an air gap on each side, so your cells would run cooler in this
application, I guess.
>I will keep you informed as to how the research is going but don't hold
>your breath - after all it is research and may take a few years to get to
>a point before it is commercially viable.
Sure... Altho you seem to be more interested in coming up with a practical
product than many other scientists and professors... I'd be happy to post
some edited version of this email of yours to our AE list, about 500 amateurs
worldwide, and a few professionals, with your permission, anon if you like.
Most of the info they get about PVs comes from fairly slanted advertising and
press releases.
> In terms of Ovshinsky's cells, these are amorphous silicon alloys
>that are made by a plasma assisted chemical vapor deposition process. Those
>big chambers that you have seen that look like a newpaper press are in fact
>evacuated chambers in which gases of SiH4, GeH4, CH4, PH3 (phosphine),
>AsH3(arsine) and B2H6 (diborane) flow. An RF plasma is used to break down
>these gases and the Silicon, germanium, carbon, hydrogen and dopant
>components are driven to the stainless steel substrate by the capacitive DC
>self-bias between anode and cathode capacitor plates.
He didn't mention that it was that complex, and I'd gotten the impression
somehow that the substrate was ordinary cheap mild steel...
>The multiple chambers are used to deposit individual layers of a device
>that may have as many as 10-12 layers !! This is not an inherently cheap
>process in small scale production (<10MW/yr.) and so the selling price of
>$4.50 a peak Watt is about the production price of these cells.
I wonder why this has to be so complicated, if they are only aiming at
5% efficiency? These things are basically just large area PN junctions
with carefully non-shading top electrode, no? Not CMOS microprocessors...
>(USSC is very secretive about its books and so the exact production price
>is generally not known
Jim Young of USSC gave me that "retail price." I assumed these things cost
them a lot less to make, at 5% efficiency, and that USSC was charging what
the market will bear, and making lots of money competing against crystalline
cells, where mounting area is not a big factor. John Page also mentioned
that Ovshinsky seemed to leave out some details in his talk.
>but Solarex's
>Thin Film Division makes a similar product and they are selling the cells
>for more than it costs to make them). As far as I am aware only the Solarex
>polycrystalline silicon cell division is making money as a solar cell
>manufacturer and they are selling at about $3.50 a peak Watt for large
>orders. There is a joint venture between Enron Corp. and Amoco (Solarex's
>parent company) to make a 10 MW/yr. thin film PV manufacturing facility in
>Virginia. Until now the amorphous silicon community has said that the cost
>of amorphous silicon PV will drop dramatically (down to less than $1/Wp) if
>they could take advantage of economies of scale and produce at least 10MWp/yr.
Seems like they have been saying that for 30 years :-) I read a paper
by Ovshinsky in Physics Review in about 1966...
>Enron has called their bluff and so let's see what happens !! Keep posted.
OK...
>In the meantime Solarex's polycrystalline silicon cell division is
>ramping up to increase their production capacity three-fold and Siemens
>Solar (what used to be ARCO Solar) is also increasing production. So there
>is a growing market for PV but primarily for remote applications in
>developing countries.
The figure I heard is that 80% of our PV production goes overseas, a lot
of that to the 2 vbillion people in the world who have no elecrcity at all.
Just mud and tin huts with dry cells and candles, I guess.
> I agree that we should start any solar home design with trying to
>meet the heating load of a house through good passive solar design (after
>insulating the house as well as possible) and then look to fund PV to supply
>the necessary but small electric load (if economically justified).
Good. Would you still like a solar shed in your yard?
> I'm still looking for students for solar homes projects - I'll let
>you know if I get any bites.
Thanks. I'm going to try to show up for the second day of the current
senior project talks. Dr. K sent me a schedule. Meanwhile, I'm helping
design a 100% solar house in Lebanon, PA, and it looks like I might
be helping design another in Seattle, where they have no sun :-), and my
episcopal friend Father Jim Evans from Phoenixville, who has built about
500 low income houses in this area over the last 10 years or so, some with
his own hands, says he'd like me to help figure out how to make cheaper
electricity for people in St Kitts, which has lots of wind, 16 mph average
in some places, and some dormant volcanos with geothermal potential. He's
building a conference center surrounded by 50 new vacation homes, which
may want solar water heaters in the roofs, combined with PVs?
Nick
\* .
'² ..
\+ OIES
\, list
\- solar-collectors
\. parts
\/ tools
\0 ceiling-fan
\1
Real.Goods
\2 Solar.Living.Sourcebook
\3 Super.E-Core
\4 mail-order-suppliers
\5 $ Solar.Electric.Specialities
\6 $ Solar.Cookers.International
\7 ( Solar.Components.Corp-KALWALL
\8 ( solar.selective.surface.coating
\9 , !hi-temp.selective.surface.coating
\M H solar-stoves Article 9176 of misc.rural:
Newsgroups: misc.rural
Path: bigblue.oit.unc.edu!concert!gatech!swrinde!pipex!uknet!EU.net!uunet!dorite!galena!davidb
From: davidb@galena.use.com (David Butler)
Subject: Photovoltaic group buy, report #1
Message-ID: <davidb.769497205@galena>
Summary: Photovoltaic group buy, report #1
Keywords: Photovoltaic, solar
Sender: news@dorite.use.com (News Admin)
Organization: IQuest Network Services
Date: Sat, 21 May 1994 05:13:25 GMT
Lines: 120
There was lots of interest in PV panels, certainly enough
to make it happen. I was surprised at the spontaneous
interest in SunFrost, so here are prices and some specs
on them. The batteries are going to be a pain. Many
wanted them, but probably only those within a reasonable
distance of SF bay area/Sacramento will be able to take
part in this aspect. They can be shipped from Santa Rosa,
Sacramento or San Jose. Unless we can get 16 or more
batteries in one drop, freight costs are very high.
The AC chargers (PowerSource) are nice, small chargers.
I have used four of the 75amp units for 4 years and really
like them. They will certainly happen.
The PV charge regulators, controls and instrumentation
come with many options. We can get Solarex and Helitrope
at good prices.
+++++++++++++++++++++++++++++++++++++++++++++++++++++++
Item #1 PV panels ++++++++++++++++++++++++++++++++++++
Solarex
VLX 53 53 watts $257.99 $4.867/watt 10 year warranty
Size=(19.72inches x 36.88inches) wt=12lbs
2 modules/ctn. Can ship UPS
MSX 64 64 watts 359.87 5.623/watt 20 year warranty
Size=(19.75inches x 43.63inches) wt=15.9lbs
2 modules/ctn. Can ship UPS
Other Solarex modules also available. Ask me.
I have talked with many dealers and the Solarex factory,
and believe the VLX is the best deal. It appears that the
10 vs 20 year warranty is marketing hype. The VLX
is a more recent design. I plan on using the VLX--
it costs 15% less.
+++++++++++++++++++++++++++++++++++++++++++++++++++++++
Item #2 batteries ++++++++++++++++++++++++++++++++++++
Lead acid: L-16 $126/each in Northern Calif/ 90-day warranty
Lots of interest but shipping is gonna
be a real killer. They weigh 135lbs/each.
They CAN NOT go by UPS or Fed-X.
NiCd: not enough interest
NiFe: not enough interest
+++++++++++++++++++++++++++++++++++++++++++++++++++++++
Item #3 SunFrost refrigerators ++++++++++++++++++++++++
2 year warranty
Following are prices at which we can buy 12vdc or 24vdc units:
110vac units are a bit less.
Energy use @ Energy use @
Model 70 F 90 F
RF19 $2,381.00 320 lbs 62 AmpHr/day 82 AmpHr/day
R19 2,123.00 310 lbs 30 AmpHr/day 50 AmpHr/day
F19 2,435.00 320 lbs 100 AmpHr/day 130 AmpHr/day
RF16 $2,330.00 300 lbs 45 AmpHr/day 65 AmpHr/day 3 panels
RF12 $1,698.00 300 lbs 28 AmpHr/day 45 AmpHr/day
R10 $1,505.00 215 lbs 15 AmpHr/day 25 AmpHr/day
F10 $1,397.00 215 lbs 55 AmpHr/day 70 AmpHr/day
RF4 $1,204.00 160 lbs 13 AmpHr/day 19 AmpHr/day
R4 1,204.00 160 lbs 9 AmpHr/day 13 AmpHr/day
F4 1,204.00 160 lbs 28 AmpHr/day 36 AmpHr/day
R1 1,102.00 100 lbs 6 AmpHr/day 9 AmpHr/day
F1 1,102.00 100 lbs 22 AmpHr/day 31 AmpHr/day
+++++++++++++++++++++++++++++++++++++++++++++++++++++++
Item #3 Battery chargers ++++++++++++++++++++++++++++++
Battery chargers (input 90-130vac)
1 year warranty
Todd PowerSrc 40amp @14.0vdc $163.98
Todd PowerSrc 75amp @14.0 or 14.8vdc 218.77
Todd PowerSrc 75amp @13.5 to 16.5vdc 229.79
Other Todd products available. They make transfer switches,
different size chargers. Ask me.
+++++++++++++++++++++++++++++++++++++++++++++++++++++++
Item #4 PV charge regulators ++++++++++++++++++++++++++
1 year full Warranty, 2-10 year prorated warranty
12/24 volt field selectable
Helitrope CC-60E 45Amp $218.65
Helitrope Fan-60 27.23
(increase CC-60E from 45amp to 60amp)
Helitrope CC-120E 90amp 309.43
Temp compensation opt 7.27
Other Helitrope & Solarex controllers available. Ask me.
+++++++++++++++++++++++++++++++++++++++++++++++++++++++
Osram Electronic Bulbs ++++++++++++++++++++++++++++++++
EL-20 20watts/1200 lumens, 120vac $18.70
Same amount of light as 75watt incandescent bulb
10,000 hr life
+++++++++++++++++++++++++++++++++++++++++++++++++++++++
+++++++++++++++++++++++++++++++++++++++++++++++++++++++
trackers: not enough interest
cable: not enough interest
inverters: not enough interest
+++++++++++++++++++++++++++++++++++++++++++++++++++++++
If you are interested in this group buy now is the time
to decide and let me know.
David Butler (707) 895-2050
8001 Signal Ridge Rd
Philo, CA 95466-0329
david@use.com
(56) Mon 24 Jan 94 6:05
By: Ken Bridges
To: ALL
Re: New Solar Technology
St:
------------------------------------------------------------------------
@MSGID: 1:325/802.5 d43aca20
This is the most info I can find to add at this point, hopefully more to
follow.
Ken
Here is the full text of the DOE Announcement of 1/18/94 -Rob
========================================================================
ENERGY DEPARTMENT ANNOUNCES BREAKTHROUGH IN SOLAR TECHNOLOGY
The Department of Energy says that a three-year government/industry
partnership has produced new thin-film solar technology that can supply all the
daytime electric power needed for a home at almost half the present cost.
Deputy Secretary of Energy Bill White said,
"The successful implementation of this cost-shared $6.26 million project
with United Solar Systems Corporation is proof-positive that, working together,
government and industry can deliver the whole package
-- innovative technology and its delivery to the marketplace."
The new photovoltaic solar panels will be manufactured at a new plant site
in Newport News, Virginia.
DOE's Assistant Secretary of Energy Efficiency and Renewable Energy,
Christine Ervin, said the practical application of these new solar panels will
also help meet administration goals of reduced greenhouse gas emissions.
"This project is an early example --- a foundation, if you will -- of what
the Climate Change Action Plan can do. At the same time, we will help create
high-skill, high-wage jobs and increase America's share of the growing world
market for environmental technologies."
The applications of this thin-film technology include
the replacement of glass panels used in constructing walls of commercial
buildings as well as other products.
Ervin said, using the new technology, thin-film solar
panels can be made, for example, into roofing shingles that could supply all
the daytime electric power needs of a south facing residential home.
Currently, costs for electricity from
photovoltaics run from 25 to 50 cents per kilowatt hour (kwh). The new
technology is expected to bring down the cost to 16 cents/kwh, and eventually
down to 12 cents kwh.
Ervin also noted that the shingles are similar in appearance from those we
use today, eliminating aesthetic objections.
----------------------------------------------------------------------
"New Silicon Cell can Halve Cost of Solar Energy"
paraphrased without permission from
The Wall Street Journal, Jan. 19, '94 page B7
Uninted Solar Systems Corp produced a new photovoltaic
cell with an efficiency of 10.2% in a 1,000 hour test.
It should drop the price of PV electricity from the
current 25-50 cents/KWh to 16 and eventually 12 cents/KWh.
[No mention of dollars/peak watt, projected life, interest
rates, or tax incentives used to estimate the price - me]
The new material is thinner and therefore cheaper than
previous amorphous silicon pannels.
The material could be fabricated into roof panels,
battery-charging panels, wall coatings for commercial
buildings, etc.
Uninted Solar Systems Corp., is a joint venture between
Canon and Stanford Ovishinksy's Energy Conversion Devices.
The Energy Department shared costs of the three-year,
$6.3 million development program. The devopment team was
led by Subhendu Ghua, vice president of research &
development. USS is building a $30 million plant, financed
largely by Cannon, in Newport News, Va. to produce the new
alloy beginning in 1995.
-- Laurin Pestes <pestes@wdi.com>
ÿÿ Amorphous PV in WSJ
-DOE-
------------------------------
--- timEd-B9
* Origin: The Solar Point, Solar Powered! (1:325/802.5)
@PATH: 325/806 333/359 101/1 396/1 270/101 151/1003 3641/1