Cold shop?

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For anyone thinking of adding a bit of solar heat to their shop, I've put up a web page (link below) with monthly maps showing how much solar energy is delivered to locations in the USA. The data represents a 30-year average.
If you're not in the USA, you may be able to find that information at www.nrel.gov
At the bottom of the page there's a link that can be used in conjunction with the map data to predict the heat output from a south-facing vertical panel. The program will run under Windows or MS-DOS (apologies to others; but this is a Windows box).
-- Morris Dovey DeSoto Solar DeSoto, Iowa USA http://www.iedu.com/DeSoto/SolarEnergy.html
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Morris, do you have one for cooling the shop? ;~)
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On Tue, 09 Jan 2007 14:48:12 GMT, "Leon"

The Ice Man Cometh with a fan. :)
Mark (sixoneeight) = 618
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Leon wrote:
| Morris, do you have one for cooling the shop? ;~)
I'm so glad you asked! <vbg>
Take a look at http://www.iedu.com/DeSoto/StirlingProject.html - one of my leisure-time play group activities looks like it'll result in a solar-powered air-conditioner...
You may also want to cool your house, too. How does a zero operating cost strike you?
-- Morris Dovey DeSoto Solar DeSoto, Iowa USA http://www.iedu.com/DeSoto
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Morris Dovey wrote:

All I can say is .... Wow. Thanks for taking the time to put up the site, the pics and the explanation. I know that was a lot of work and I personally found it to be fascinating.
Good work!
Robert
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Very Cool

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Keep us apprised of when you get that perfected. My dad has always said there should be a solar air conditioning capability similar to how the old natural gas refrigerators used to work.

ZOC is great as long as initial investment and amortized ownership costs are below what a conventional system would cost. IMO, this is where solar is having problems right now. Sure, I can get panels that would generate enough electricity to run my house amd sell extra back to the grid during times I'm not using it. However, the cost of ownership indicates it would take at least 10 years to reach break-even and I'm not convinced that materials technology is anywhere near having something like that last long enough without repairs to ever pay back. That also assumes no little issues like hailstorms or kids' balls wreaking havoc on the system.
It's been a couple of years since I investigated solar electric panels (an obvious winner in a place like southern Arizona). I think I calculated that electricity would have to reach 25 to 30 cents per KWH to even make the panels close to competitive.
I realize what you are proposing is quite different, and I believe that solar heating has a bit better payoff capability. Really do hope you can perfect the solar A/C approach -- that would be way cool (no pun intended).
+--------------------------------------------------------------------------------+ If you're gonna be dumb, you better be tough +--------------------------------------------------------------------------------+
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There are (as always, I guess) some very excited researchers, engineers and manufacturers working in Silicon Valley on systems with much higher reliability, manufacturability and simplicity, and much lower cost structures than have been seen in recent years. I don't have my checkbook out yet, but what seems feasible is a much lower local production cost. One of the benefits to that is a much lower transport infrastructure cost as well, at least for the locally produced power.
There is, I am certain, still a lot to learn in this area. And folks are looking forward to it as well.
Patriarch
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Mark & Juanita wrote: | On Tue, 9 Jan 2007 09:22:45 -0600, "Morris Dovey"
|| You may also want to cool your house. How does a zero || operating cost strike you? | | ZOC is great as long as initial investment and amortized | ownership costs are below what a conventional system would cost.
Yes - and here is where the fluidyne (a short name for a liquid piston stirling cycle engine) absolutely shines for a limited set of applications.
The engine itself is a plumbing construct, partly filled with water and the remainder filled with a air. There are no special requirements: neither the water nor the air need be particularly clean and there is no pressurization.
This engine operates at temperatures below the boiling point of water and without producing particularly high pressures. The only moving parts are the air and water; and there aren't any "wear points".
The diameters and lengths of the plumbing elements are important; but there doesn't appear to be any need to be fussy about precision.
If you knew the plumbing measurements, you could probably build your second engine out of (mostly) schedule 40 PVC pipe in less than a half hour. The engine could be expected to outlast your (great-?)grandchildren if you protected it from UV and abuse.
If you powered it from a flat-panel solar collector, you'd probably want to replace the polycarbonate glazing every quarter-century or so. A 6mm x 48" x 96" sheet of twin-wall polycarbonate glazing cost me about $40 last time I shopped for it.
I don't yet have exact numbers on what this thing is going to cost to produce (I'll guess less than US$100/HP for engine and collector); and I don't even have a clue as to what conventional systems cost to produce, operate, or maintain - so I can't help much with your cost analysis.
| IMO, this is where solar is having problems right now. Sure, I can | get panels that would generate enough electricity to run my house
<snip photovoltaic electricity cost lament>
Agreed. Photovoltaics are over-priced and under-efficient; and, as long as people are willing to pay too much for too little, improvements will come slowly.
I don't have the resources to solve the photovoltaic production cost problem (there is at least one that I'm aware of) so I don't waste my time on it - but electricity doesn't necessarily provide the best solution for /all/ problems.
If solar is having problems, it's because people insist on a "magic bullet" - a single, comprehensive solution to all energy problems - and solar is not a magic bullet (at least not yet).
-- Morris Dovey DeSoto Solar DeSoto, Iowa USA http://www.iedu.com/DeSoto/SolarEnergy.html
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Morris Dovey wrote: | Mark & Juanita wrote:
|| IMO, this is where solar is having problems right now. Sure, I can || get panels that would generate enough electricity to run my house | | <snip photovoltaic electricity cost lament> | | Agreed. Photovoltaics are over-priced and under-efficient; and, as | long as people are willing to pay too much for too little, | improvements will come slowly. | | I don't have the resources to solve the photovoltaic production cost | problem (there is at least one that I'm aware of)
Y'know, I hate when people claim to have the solution to one of my problems but refuse to tell me what it is - but I realized that was exactly what /I'd/ done here! Please accept my apologies.
A technical discussion of photovoltaic production is surely off-topic; but in an effort to live by the golden rule, I've put up a web page with a drawing showing a mechanism and a process for making very inexpensive waferless solar cells. You can find it at the link below.
Now, what's really fun is that while I was putting the drawing together, I had a flash of insight as to how these cells might be incorporated into one of my air-heating panels in such a way that _both_ sides of the cells could be used for power generation - I don't think the power output would be doubled; but it might come close...
-- Morris Dovey DeSoto Solar DeSoto, Iowa USA http://www.iedu.com/DeSoto/Ribbon.html
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Not solar but,
In Houston an industrial office complex near my home has a particular all concrete building that uses water pipes that run under ground to cool the building. The building is about 3000 sq ft and the owner had the system installed after he bought the building. 10 years ago he told me that his average cooling bill was about $30 per month.
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What you have stated is true unless you're off grid to begin with. My shop and home in SW Colorado is on solar electric power. Solar equipment plus install was a wash with bringing in a power line. I'm set with 240 volt power, close to 1800 watts of panels, and enough battery to run things for a few days (shop tools) or a week (house w/o shop) plus I have no monthly bill. Only problem is that I'm not using it most of the time since I'm back in Phx permanently. It would be nice to be selling that much power back to the power company but the $25 grand needed to hook up power kind of messes up that idea!
Gary
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Here is a chea[ way to heat your shop....
http://www.lowes.com/lowes/lkn?action=productDetail&productId1258-51644-F274815&detail=cr&lpage=none
on sale 1/2 price
GeeDubb wrote:

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It's still early in the morning, but I'm having a bit of a challenge processing this data.
The map seems to indicate that, for example, southern Arizona has more heating potential in December than in August. And that the SF Bay area seems pretty close to the same number all year.
Am I reading this correctly? Is this 'sun angle'?
Patriarch, off to work...
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I have the same interpretation problem.
I have two 4x8ft solar panels for heating domestic potable water. Installed in mid 80's. I know the relative heat gain over the months.
The colours make sense for my location SE PA, but the legend does not make sense.
According to the legend, my location has less heat gain in April/May than March. Does not happen this way for me.
Dave Paine.

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Tyke wrote: | I have the same interpretation problem. | | I have two 4x8ft solar panels for heating domestic potable water. | Installed in mid 80's. I know the relative heat gain over the | months. | | The colours make sense for my location SE PA, but the legend does | not make sense. | | According to the legend, my location has less heat gain in | April/May than March. Does not happen this way for me.
I'd guess that your DHW panels aren't vertical (vertical is best for winter heat only). Since we want hot water year-round, DHW panels are more likely to be set at an angle that works most efficiently at vernal and autumnal equinox angles.
How's my guess?
-- Morris Dovey DeSoto Solar DeSoto, Iowa USA http://www.iedu.com/DeSoto
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Good guess. I read "Vertical" but did not think about how this affected performance. This makes sense now.
My latitude is 41.5 deg N. I installed the panels at about 45 deg to give slightly better performance in winter. I can get TOO much gain in summer if water use is low.
Dave Paine.

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Tyke wrote:
| Good guess. I read "Vertical" but did not think about how this | affected performance. This makes sense now.
Most of us aren't used to thinking of seasons in geometric terms. Since the earth's axis of rotation is tilted (approximately) 23.43929 degrees from its orbital plane, there's a difference of almost 47 degrees between summer and winter solstices. That's a big swing.
| My latitude is 41.5 deg N. I installed the panels at about 45 deg | to give slightly better performance in winter. I can get TOO much | gain in summer if water use is low.
Good plan. BTW, NREL also has the same kind of map data available for panels tilted at increments from location latitude. I'd guess that those will better reflect (no pun intended) the behaviors you've experienced.
-- Morris Dovey DeSoto Solar DeSoto, Iowa USA http://www.iedu.com/DeSoto/SolarEnergy.html
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Patriarch wrote:
| The map seems to indicate that, for example, southern Arizona has | more heating potential in December than in August. And that the SF | Bay area seems pretty close to the same number all year. | | Am I reading this correctly? Is this 'sun angle'?
Yup. Note that this data is for _vertical_ panels. When the sun is high overhead during the summer, it "sees" much less capture area. In winter the sun is much lower and "sees" a much greater capture area.
Not accounted for in the map data is a significant increase in reflected radiation during winter months - as much as a 95% increase is possible from clean snow...
-- Morris Dovey DeSoto Solar DeSoto, Iowa USA http://www.iedu.com/DeSoto/SolarEnergy.html
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There's _seldom_ clean snow where we are. Seldom _any_ snow. Heck, I still have some very nice english roses that don't belive it's January right now. Still blooming.
Solar here is an interesting challenge. I'll have to give it more thought over the next week or so, as I'm traveling about. There's panels on the roofs of several of the homes on my block, doing heat gain for their swimming pools. Those folks are happy with them, so there's a start.
Patriarch
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