# Solar Powered Ice Maker?
**URL:** https://boards.straightdope.com/t/solar-powered-ice-maker/256812
**Category:** Factual Questions
**Created:** [July 25, 2004, 4:22pm UTC](https://boards.straightdope.com/t/solar-powered-ice-maker/256812 "2004-07-25T16:22:48Z")
**Posts on this page:** 20
**Page:** 1
### Author:  [@Tuckerfan](https://boards.straightdope.com/u/Tuckerfan)
#### Post date: [July 25, 2004, 4:22pm UTC](https://boards.straightdope.com/t/solar-powered-ice-maker/256812/1 "2004-07-25T16:22:48Z")
[This](http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=378&item=6913627773&rd=1) was linked to on another message board I frequent, and along with it’s too good to be true promises, it contains this little gem
> [@](#):
>
> Find out how we made this 25 pound block of ice the girls are holding. We made it VERY simple, VERY easily and VERY efficiently. You don’t need a refrigeration license to make this, but you might need a hack saw. No soldering, no welding, everything was either off the shelf or FREE. The system could even run off your car cigarette lighter socket, lots of ice for the scout trip into the wilds. This is 100 year old technology with 2003 year items. It was easy, a 6th grader could do it for a science fair.
> There is MORE cooling in the book as well. Cool your house while you water the lawn, or flush the toilet.
> I’m talking over 12,000 BTU’s / hour of cooling at 65F. ( This is _NOT_ a SWAMP or Evaporative COOLER)
Now, I’m a fairly avid reader of all kinds of “lost” technologies and I’ve _never_ heard of anything like this. Anyone have any ideas of what the heck this could be, if it is legit? (That’s a mighty big “if” I realize.)
---
### Author:  [@El\_Cid\_Viscoso](https://boards.straightdope.com/u/El_Cid_Viscoso)
#### Post date: [July 25, 2004, 5:54pm UTC](https://boards.straightdope.com/t/solar-powered-ice-maker/256812/2 "2004-07-25T17:54:19Z")
Hi Tuckerfan,
From what I know of Steven Harris (author of _Sunshine to Dollars_, from the ebay auction), these claims are bona fide, but more than a little vexing. It’s notable to add that many of his same ideas have been sold, in various formats, from the backs of _Science News_ magazines for almost twenty years; Harris’ book appears to be a rather hit-or-miss compendium.
My father has personally implemented several of these “old technologies,” including scrounged, solar-powered garden irrigation, a solar shower and solar refrigeration. So I’ve seen them in clunky, onerous practice, and they’re out there on the Web if you’d like to look for them.
Here are some breadcrumbs:
> [@](#):
>
> \*\*Pupil’s icy invention wows the world \*\* – 11 August 2002
>
> […]
>
> His design concept is based on solar energy principles. A glass tank on top of the fridge, containing water and a sponge, harnesses the sun to power a cooling circle - using no electricity and creating no pollution. As the water evaporates, the fridge can cool down to -5°C…
>
> Pasted from \<[http://www.suntimes.co.za/2002/08/11/news/news17.asp](http://www.suntimes.co.za/2002/08/11/news/news17.asp)\>
and
> [@](#):
>
> The sun’s energy can be applied to refrigeration in two ways. Photovoltaic cells can be used to produce electricity to power a conventional low-energy domestic fridge, or heat from the sun can be used directly to drive a refrigeration system based on evaporative cooling - a more sophisticated version of the Coolgardie Safe. The Monash research is based on the second system as it is simpler and more efficient, as well as robust and inexpensive.
>
> Dr Hu has already determined that the most practical, cheapest and least toxic chemicals to use in the system are methyl alcohol (or methanol) and a form of charcoal known as activated carbon.
>
> The process is simple (see diagram). During daylight hours, sunlight falls on a solar collector which contains activated carbon saturated with methanol under a vacuum.
>
> Pasted from \<[http://www.monash.edu.au/pubs/eureka/Eureka\_95/fridge.html](http://www.monash.edu.au/pubs/eureka/Eureka_95/fridge.html)\>
I found these links on a site called [halfbakery.com](http://www.halfbakery.com/idea/Solar_20AC#1090560453), one part blog, two part sounding board and one part crackpottery.
You might like to know I am throroughly obsessed with these practices, especially since the modern state of photovoltaics is a largely losing proposition: all of the cells on our farm, for example, cost far more in fossil fuels to manufacture than they will ever, in their lifetimes, replace. I believe the key to sustainability lies in the recesses of our minds, not in the thinness of wafers or the compactness of circuitry. It’s out there, and it’s up to people like you and me to find it.
Yours truly,
El Cid
---
### Author:  [@Tim\_T-Bonham.net](https://boards.straightdope.com/u/Tim_T-Bonham.net)
#### Post date: [July 26, 2004, 3:52am UTC](https://boards.straightdope.com/t/solar-powered-ice-maker/256812/3 "2004-07-26T03:52:11Z")
> [@](#):
>
> You don’t need a refrigeration license to make this,
What???
I’ve had freezers, icemakers, refrigerators, etc. running in my house for years, without ever needing a _refrigeration license_. I don’t even know where in City Hall I would go to apply for one, 'cause I’ve never heard of this!
Seeing something like this tossed in there just really raises warning signals to me. Tends to make me lean much more toward the **sounds too good to be true** position.
---
### Author:  [@Larry\_Mudd](https://boards.straightdope.com/u/Larry_Mudd)
#### Post date: [July 26, 2004, 4:26am UTC](https://boards.straightdope.com/t/solar-powered-ice-maker/256812/4 "2004-07-26T04:26:06Z")
> [@t-bonham@scc.net](#):
>
> I’ve had freezers, icemakers, refrigerators, etc. running in my house for years, without ever needing a _refrigeration license_.
You need a refrigeration license to maintain or repair air-conditioning/refrigeration units. To get one, you have to pass an exam to prove you know how to handle freon & stuff. You need to be licensed to manufacture or sell them, too.
It’s not like a TV license. 😃
---
### Author:  [@commasense](https://boards.straightdope.com/u/commasense)
#### Post date: [July 26, 2004, 5:31am UTC](https://boards.straightdope.com/t/solar-powered-ice-maker/256812/5 "2004-07-26T05:31:50Z")
> [@El Cid Viscoso](#):
>
> the modern state of photovoltaics is a largely losing proposition: all of the cells on our farm, for example, cost far more in fossil fuels to manufacture than they will ever, in their lifetimes, replace.
This doesn’t sound right at all. Do you have a cite?
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### Author:  [@citrus\_x\_paradisi](https://boards.straightdope.com/u/citrus_x_paradisi)
#### Post date: [July 26, 2004, 7:46am UTC](https://boards.straightdope.com/t/solar-powered-ice-maker/256812/6 "2004-07-26T07:46:38Z")
> [@El Cid Viscoso](#):
>
> I found these links on a site called [halfbakery.com](http://www.halfbakery.com/idea/Solar_20AC#1090560453), one part blog, two part sounding board and one part crackpottery.
[Aside] Uh, no. 😉 The HB is one part message board and one part thinktank. It’s a compendium for whimsical invention ideas that are similar to Japanese _chindogu_.[/Aside]
Carry on!
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### Author:  [@Bryan\_Ekers](https://boards.straightdope.com/u/Bryan_Ekers)
#### Post date: [July 26, 2004, 8:08am UTC](https://boards.straightdope.com/t/solar-powered-ice-maker/256812/7 "2004-07-26T08:08:21Z")
> [@t-bonham@scc.net](#):
>
> What???
>
> I’ve had freezers, icemakers, refrigerators, etc. running in my house for years, without ever needing a _refrigeration license_. I don’t even know where in City Hall I would go to apply for one, 'cause I’ve never heard of this!
That’s not a refrigeration license! You’ve just scratched out “dog” and written in “refrigeration!”
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### Author:  [@Gorsnak](https://boards.straightdope.com/u/Gorsnak)
#### Post date: [July 26, 2004, 8:17am UTC](https://boards.straightdope.com/t/solar-powered-ice-maker/256812/8 "2004-07-26T08:17:08Z")
Seems to me that it should be possible to build a solar fridge on the same principle as a propane fridge, no? Course, that would require licenses for handling refrigerants. But I can’t see why it wouldn’t work.
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### Author:  [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)
#### Post date: [July 26, 2004, 12:18pm UTC](https://boards.straightdope.com/t/solar-powered-ice-maker/256812/9 "2004-07-26T12:18:46Z")
> [@El Cid Viscoso](#):
>
> the cells… cost far more in fossil fuels to manufacture than they will ever, in their lifetimes, replace.
Yep. And that’s why I get a chuckle whenever an environmentalist says we should implement PV systems for power production. They believe a PV system is cleaning burning. :rolleyes: Note, however, that this could change in the future, if someone figures out how to make them more efficient…
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### Author:  [@Desmostylus](https://boards.straightdope.com/u/Desmostylus)
#### Post date: [July 26, 2004, 12:35pm UTC](https://boards.straightdope.com/t/solar-powered-ice-maker/256812/10 "2004-07-26T12:35:53Z")
It’s most likely something like this:
> [@](#):
>
> [Isaac Solar Ice Maker](http://www.thesustainablevillage.com/servlet/display/microenterprise/display/14)
>
> Ammonia absorption refrigeration technology was developed in the 19th century and is still used in industrial applications.
>
> \
>
> During the day the solar collector focuses the energy of the sun onto the ammonia generator in the collector trough. Solar heat distills pure ammonia vapor from the water-ammonia solution in the generator. The vapor condenses in the cooling coils and collects as liquid ammonia in the receiving tank in the evaporator.
>
> At the end of the day, the user switches three valves from the Day to Night position to allow the ammonia to evaporate in the ice compartment, providing the refrigeration to freeze the water. The resulting vapor is absorbed back in the generator.
---
### Author:  [@spingears](https://boards.straightdope.com/u/spingears)
#### Post date: [July 26, 2004, 12:41pm UTC](https://boards.straightdope.com/t/solar-powered-ice-maker/256812/11 "2004-07-26T12:41:20Z")
Dr Hu has already determined that the most practical, cheapest and least toxic chemicals to use in the system are _methyl alcohol (or methanol)_ and a form of charcoal known as activated carbon.
NOT SO!
Methyl alcohol aka methanol is a deadly poison. A small percentage is added to ethyly (drinking) alcohol to make denatured alcohol.
Exposure to methanol can have disasterous consequences.
Dr. Hu is full of HUEEY!
---
### Author:  [@Gorsnak](https://boards.straightdope.com/u/Gorsnak)
#### Post date: [July 26, 2004, 5:40pm UTC](https://boards.straightdope.com/t/solar-powered-ice-maker/256812/12 "2004-07-26T17:40:18Z")
> [@El Cid Viscoso](#):
>
> You might like to know I am throroughly obsessed with these practices, especially since the modern state of photovoltaics is a largely losing proposition: all of the cells on our farm, for example, cost far more in fossil fuels to manufacture than they will ever, in their lifetimes, replace. I believe the key to sustainability lies in the recesses of our minds, not in the thinness of wafers or the compactness of circuitry. It’s out there, and it’s up to people like you and me to find it.
I’d like to see some substantiation of these claims. I’ve done a little hunting around, and [this study](http://www.ecotopia.com/apollo2/pvepbtoz.htm) dating from 2000 says that the energy payback time on photovoltaic cells is around 8-11 years out of a typical lifespan of approximately 30 years. That’s a far cry from “far more fossil fuels to manufacture than they will ever replace.” Note that the study accounts not only for manufacturing costs, but also installation and decommisioning. Also note that the study does _not_ assume the use of castaway silicon from integrated circuit chip manufacture, but calculates the energy costs as if the silicon was being refined from scratch solely for PV cells. Based on some assumptions, the study projects the energy payback time on PV cells in 2010 will be 2 years. I don’t know if those assumptions are being borne out, being nearly halfway to 2010 from the date of the study as we are, but in any event, it looks like your claim is simply false.
Care to back it up? **Crafter\_Man** can feel free to respond as well, since he apparently believes the same thing.
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### Author:  [@Ethilrist](https://boards.straightdope.com/u/Ethilrist)
#### Post date: [July 26, 2004, 6:01pm UTC](https://boards.straightdope.com/t/solar-powered-ice-maker/256812/13 "2004-07-26T18:01:03Z")
> [@spingears](#):
>
> Dr. Hu is full of HUEEY!
Dude. Chill.
get it? chill?
---
### Author:  [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)
#### Post date: [July 26, 2004, 6:45pm UTC](https://boards.straightdope.com/t/solar-powered-ice-maker/256812/14 "2004-07-26T18:45:27Z")
> [@Gorsnak](#):
>
> **Crafter\_Man** can feel free to respond as well, since he apparently believes the same thing.
Want another “study”? Here ya go:
> **[35489.pdf](https://www.nrel.gov/docs/fy04osti/35489.pdf)**
>
> 158.85 KB
The problem with these “studies” is two-fold. First of all, they are not objective; I believe the researchers have a vested in more $$ going into PV research and development. Secondly, they don’t even begin to take into account the _true_ amount of energy it requires to make a PV array. Did they take into account the energy required to transport the raw materials? Nope. Those trucks burn a lot of diesel fuel. Did they amortize the amount of fossil fuel required to build and maintain the multi-million dollar equipment necessary to purify the raw materials? Nope. They just assumed these were “fixed costs” and ignored them. I could go on and on, but hope fully you get the drift.
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### Author:  [@Finagle](https://boards.straightdope.com/u/Finagle)
#### Post date: [July 26, 2004, 8:07pm UTC](https://boards.straightdope.com/t/solar-powered-ice-maker/256812/15 "2004-07-26T20:07:15Z")
> [@Crafter\_Man](#):
>
> Want another “study”? Here ya go:
>
> [http://www.nrel.gov/docs/fy04osti/35489.pdf](http://www.nrel.gov/docs/fy04osti/35489.pdf)
>
> The problem with these “studies” is two-fold. First of all, they are not objective; I believe the researchers have a vested in more $$ going into PV research and development. Secondly, they don’t even begin to take into account the _true_ amount of energy it requires to make a PV array. Did they take into account the energy required to transport the raw materials? Nope…
```
Well, the raw material is pretty much sand and the cost per ton had got to be pretty low. I'm not sure that producing the PV array has to consume fossil fuels. If the company manufactures solar cells, couldn't they bootstrap part of their energy requirements onto solar cells?
I'm not sure why you're assuming that putting more $$ into PV research would be a bad thing -- certainly it appears as though more cost-effective technology is on the way. As you pointed out, the technology is promising if it can be made cheaper and more efficient, and that seems to be the case.
Just a couple of hits from Google:
http://www.economist.com/science/tq/displayStory.cfm?story_id=2019909
http://www.cnn.com/2003/TECH/biztech/10/02/solar.cells.reut/
```
Even if these are just hype, there’s enough work going on so that I think cheap solar cells are only a matter of time. The fossil fuel \> energy produced argument really only applies to existing silicon cell technology and is therefore pretty bogus.
---
### Author:  [@Excalibre](https://boards.straightdope.com/u/Excalibre)
#### Post date: [July 26, 2004, 8:24pm UTC](https://boards.straightdope.com/t/solar-powered-ice-maker/256812/16 "2004-07-26T20:24:32Z")
> [@spingears](#):
>
> Dr Hu has already determined that the most practical, cheapest and least toxic chemicals to use in the system are _methyl alcohol (or methanol)_ and a form of charcoal known as activated carbon.
>
> NOT SO!
>
> Methyl alcohol aka methanol is a deadly poison. A small percentage is added to ethyly (drinking) alcohol to make denatured alcohol.
>
> Exposure to methanol can have disasterous consequences.
>
> Dr. Hu is full of HUEEY!
Yeah, which tells you something about the other chemicals he tried! You don’t even want to _know_ what they’d do to you.
---
### Author:  [@Quercus](https://boards.straightdope.com/u/Quercus)
#### Post date: [July 26, 2004, 8:35pm UTC](https://boards.straightdope.com/t/solar-powered-ice-maker/256812/17 "2004-07-26T20:35:39Z")
> [@](#):
>
> The problem with these “studies” is two-fold. First of all, they are not objective; I believe the researchers have a vested in more $$ going into PV research and development. Secondly, they don’t even begin to take into account the true amount of energy it requires to make a PV array. Did they take into account the energy required to transport the raw materials? Nope. Those trucks burn a lot of diesel fuel. Did they amortize the amount of fossil fuel required to build and maintain the multi-million dollar equipment necessary to purify the raw materials? Nope. They just assumed these were “fixed costs” and ignored them. I could go on and on, but hope fully you get the drift.
Well, that’s possibly a decent point, but then raises the question of what are all the equivalent costs for whatever the PV is replacing? Mining, refining, transporting and building the infrastructure to burn fossil fuels (plus, as you point out, mining and transporting the raw materials for the turbines, dynamos, power lines, etc.) all require energy use as well. If you’re comparing, you have to look at the same costs for both sides.
And at any rate, with a calculated four-year or even ten year payback on a thirty year lifespan, you’d have to be leaving out a **LOT** of other costs to change the conclusion that energy-wise, they’re a good investment.
---
### Author:  [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)
#### Post date: [July 26, 2004, 8:43pm UTC](https://boards.straightdope.com/t/solar-powered-ice-maker/256812/18 "2004-07-26T20:43:28Z")
**Finagle** : There are other things they’re leaving out… for a PV array to compete with grid power, an inverter must be used, which gobbles up energy. Oh, and did I mention the room full of deep cycle batteries? Gee, I wonder if they forgot to determine the amount of fossil fuels expended to manufacture all the batteries.
But now I’ll let you in on a little secret: you really don’t have to do a study. You only have to understand _economics_. If PV arrays _really_ generated **net** power, the power companies would build PV-based power plants and make a real _profit_ selling the energy. But they don’t. Why? Because it’s not worth it; the economic reality _alone_ tells you more energy is expended building a PV-based power system that what you get out of it.
---
### Author:  [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)
#### Post date: [July 26, 2004, 8:54pm UTC](https://boards.straightdope.com/t/solar-powered-ice-maker/256812/19 "2004-07-26T20:54:50Z")
> [@Quercus](#):
>
> Well, that’s possibly a decent point, but then raises the question of what are all the equivalent costs for whatever the PV is replacing? Mining, refining, transporting and building the infrastructure to burn fossil fuels (plus, as you point out, mining and transporting the raw materials for the turbines, dynamos, power lines, etc.) all require energy use as well. If you’re comparing, you have to look at the same costs for both sides.
No you don’t. They very fact that they’re doing it on a large scale _proves_ that they get more energy out of it than what was expended to retrieve it. It would be virtually impossible for this _not_ to be the case.
> [@](#):
>
> And at any rate, with a calculated four-year or even ten year payback on a thirty year lifespan, you’d have to be leaving out a **LOT** of other costs to change the conclusion that energy-wise, they’re a good investment.
Tell you what, **Quercus**. Since you believe a PV-based power distribution system pays for itself after 3 years (or whatever), why don’t you “get off the grid” and invest in a home-based PV power system? It should pay for itself after a few years, correct? Sounds like a good deal to me! Just be careful not to smoke in your basement, since it will be full of lead acid batteries…
---
### Author:  [@Gorsnak](https://boards.straightdope.com/u/Gorsnak)
#### Post date: [July 26, 2004, 10:47pm UTC](https://boards.straightdope.com/t/solar-powered-ice-maker/256812/20 "2004-07-26T22:47:18Z")
> [@Crafter\_Man](#):
>
> But now I’ll let you in on a little secret: you really don’t have to do a study. You only have to understand _economics_. If PV arrays _really_ generated **net** power, the power companies would build PV-based power plants and make a real _profit_ selling the energy. But they don’t. Why? Because it’s not worth it; the economic reality _alone_ tells you more energy is expended building a PV-based power system that what you get out of it.
First, I will note that you have produced absolutely no evidence for your position.
Second, you obviously didn’t read my link.
> [@Crafter\_Man](#):
>
> they don’t even begin to take into account the true amount of energy it requires to make a PV array. Did they take into account the energy required to transport the raw materials? Nope. Those trucks burn a lot of diesel fuel. Did they amortize the amount of fossil fuel required to build and maintain the multi-million dollar equipment necessary to purify the raw materials? Nope.
> [@the link](#):
>
> In addition to energy embodied in PV materials, the energy embodied in the machines used in manufacturing need to be taken into account. Similarly, the energy used to manufacture the machines that are used to manufacture the production machinery needs to be taken into account, and so on. However, in an energy intensive product such as a PV panel the energy embodied in the materials far exceeds the energy embodied in the production machinery, and the latter can be neglected for practical purposes. Indirect energy, such as for heating, lighting, office equipment and transport is a significant overhead and must be included.
Third, your economic argument is faulty. PV arrays generating net energy doesn’t mean they’d be in use by power companies, simply because their non-energy-related costs may more than make up the difference. Costs are not directly proportionate to energy inputs, you know. The cost of real estate for large arrays, for example, or the cost of labour for manufacture, installation, and maintenance. Anyways, it’s already possible to financially break even by going off the grid with PV panels. It’s just that most people aren’t in a position to pay their next 12 years or whatever worth of electricity bills up front, nor do they want the hassle of converting. Now, I’m not sure to what extent subsidies come into play here, or I’d be suggesting that this demonstrates conclusively that there’s a net energy gain. After all, it’s not like the transportation companies don’t charge for the fuel they use, or the manufacturing plants don’t charge for their capital investments in machinery. However, I don’t know how much the market is distorted by governments, so I’m not going to make that argument.
So, can you give us any real evidence?
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