Friday, October 19, 2012

Solar Project Review

Last week I made a Solar Still to have for a secondary way to make the water from the rain water harvest system drinkable. I followed a plan I found on Mother Earth News almost to the letter so I could give the project a fair shake. Here is what I came up with.

The plans were clear and I made the box accordingly only changing one or two small things due to using what I had on hand and recycling used materials. I did have to buy a piece of glass because I am not a glass cutter and broke several attempts of cutting my own. I guess you have to have a light touch to do it and I don't.
 At first I was not going to put the reflective material on the back door because I didn't think it was needed, but decided to do it anyway. That way I could say it was just like the one in the plans.
I used a five gallon jug for the water collector and hooked everything up air tight to keep the moisture inside.
10/11/12 - Using a glass baking dish and two glass meatloaf dishes I added the water to the still and stood back to watch it happen. I soon found out this was going to be worse then watching water boil so I left it alone for a couple of hours. I checked on the progress again and saw this was like watching molasses flow in the winter. If you have never seen that then all I can say is that it is really, really slow. 
10/13/12 - Two days later I revisited the Still thinking I would be out of water in the containers, but low and behold I still had plenty to go. Condensation was on the upper glass and it appeared to be running off and into the pipe and down in the jug. It was doing what it was intended to do, but not very fast.
Two days and one cup of water, not a good start so far.

10/17/12 - Four days have past and now the water that was captured in the jug is gone. The only explanation is a leak somewhere. Air was getting in and the water was being lost instead of doing what the still was designed for and being caught in the jug.
After close evaluation I found where the top glass adhesive had dried and pulled away leaving a gap where outside air was getting in. A quick fix by using silicone and placing a bead all the way around the edge of the glass did the trick. So now we are back in business, I think.

 10/18/12 - A day later and with high expectations I checked the still, nothing. The condensation is there, but it is not forming heavy enough droplets to run into the jug. The water jug has condensation inside as well leading me to believe I need to cool the jug or keep it in the shade by wrapping a towel around it. Today I will do that and see what happens. I don't know if the equalizing temperatures in the box and jug have anything to do with it or not, but it's worth a try.
I also tightened up to back door because I thought maybe I was loosing some moisture from it as well, but I know I wasn't.

10/19/12 - Not everything I build has to turn out I don't guess. I am ready to pull the plug on this little project. The still has been a pain in my side for two weeks now without showing any positive results. At most I can get maybe a cup of water every couple of days.  I can't imagine I did this wrong or did not give this project a fair shake. Stick a fork in it folks, it's done.
 
End results:
Cost to build if bought everything new - $70.00
Distilled water made over two weeks - 1/8th Gallon
Cost for one store bought gallon of Distilled water - $0.79
Money lost  - $69.21

I will probably turn the still into a solar dehydrator or a solar cooker. I need a smaller one of both so we will see.        

The next solar project will be a heater for my shop. I am collecting beer cans right now for it. Just two more thirty packs to go, LOL
  

14 comments:

  1. Sad the still didn't work - thanks for the detail.

    How are you going to make a solar heater out of beer cans...?

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    1. Dani, Thanks for the comment,
      Many different types of the can heater can heater can be found on you tube. Of course I have my own design but in the end it takes the suns absorbed heat and heats the shop.

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  2. Win some lose some. Would it work better in the summer heat??

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    1. Who knows Rob. If I still have it around I might try it again. Thanks

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  3. At least you tried, and thanks for sharing your results! I'm saving beer bottles right now for some home brew, recycling can have it's perks ☺

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    1. Thanks Kelly, There's nothing wrong with a little brew.

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  4. Thank you for completing the solar still. I was waiting to here your findings, and end result to see if this is something we should try because we use distilled water. I think we will wait on this process and continue to buy the distilled water for now.

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    1. Thanks for the comment Sandy. Being that this did not work, I am planning a Biosand Filter to help with the drinking water.

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  5. I would think that plastic would work as well or better than glass as you could tape it and even make a mushroom shape to get more surface area up and exposed to the sun. Side reflectors like a solar oven would throw even more heat into the device. It really should work better. We have a spring so I never experimented on that kind of thing but it just has to work if you can get the temperature and humidity up inside.

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    1. That's possible SBF but I decided to do it just like the plans so if it did not work then at least the design factor was not in question. I agree more heat would probably do it and I might even try that out during the re-construction of it becoming an oven.

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  6. Very interesting. I think Sunnybrook Farm has some good ideas there. I am glad you share the failures to so others don't make the same mistakes.

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  7. After those results, the thought of drinking up the 30 cans of beer are probably easier than it sounds.. Thanks for sharing.

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    1. Izzy I think it's more of an excuse than anything.

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