# Anyone doing any solar projects?



## ThatDaveGuy

I admit this might not be the best spot for this but then the board machinery would have had to allow me to send a PM to ask someone about it :001_tongue:

I looked around and didn't see a category or conversation on any solar DIYery, did I just overlook it? I have been mulling it over (a good part of my winters are spent honing my mulling skills) and I am considering fabricating my own lil low-tech solar heater assy. Some ready research (thank you internet!) has coughed up some good ideas on fairly simple/ fairly inexpensive solar hot air collectors. We have a southern face on our house that gets sun all day and could gather a substantial amount vented to a rockbox in the crawlspace, convection heating from there into the house, etc.

Anyone here doing anything similar? I'd really be open to any input on mistakes to be avoided and interesting ideas to optimize the operation.


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## Mr Chips

there is a green home improvement forum HERE,


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## Dwoodsmith

My landlord has a few square feet panel on his garage roof. It's hooked up to three car batteries, wired in parallel, powering a simple high wattage inverter. I think he got it at Grainger, where they also have huge batteries. He just putters around but he can fire up a power tool anytime he wants. On demand power is only limited by the capacity of the battery bank. Available power is just limited by square footage of panel and a little thing called the sun.


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## Red Squirrel

I want to get into solar at some point, but panels arnt cheap. Would take a while to make up the cost. But guess when going green,it's more about just saving money, it's to actually help the environment. Hard to justify when your power comes from hydro dams though.


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## operagost

I've been leaning toward wind because I'm impressed at what a small turbine attached to your house can do in comparison to a much larger solar panel array. I was under the impression that noise would be a factor until I saw small ones attached to houses right in the middle of town that were inaudible from the street.


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## Red Squirrel

I've thought about wind too, and it's much cheaper as you can make your own turbine. I like the concept of the vertical turbines as the motor can be stationary and makes the wiring easier.

Solar only really works when the sun is out. At this time of year that might be like 2 hours a day in average, while wind is quite constantly present day and night.


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## Dwoodsmith

Check out the links on this site. energy21 free energy website​ Encyclopedia of Free energy, Australian energy21 website search engine.​ www.energy21.freeservers.com - View by Ixquick Proxy​


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## Piedmont

Well, I wouldn't do photovoltaics (sunlight to electricity). Sunlight doesn't convert to electricity well, the photovoltaic panels are typically only 11-14% efficient, the rest of the energy turns mosly into heat which is bad for photovoltaics the hotter they get the less efficient and less electricity they make. 

What sunlight does convert well to, is heat. I'm sure you've left a tool in the sun and felt first hand how well it converts to heat. Solar panels that run fluid through them are typically in the 75-80% efficient range, air is not as efficient for transferring the heat. I'm not sure what you were thinking of doing, I've heard of drilling out the tops & bottoms of soda cans, stacking them one on top of the other, painting them black, and putting them in an insulated case with air blowing in the bottom when the sun is out (cansolair I believe is exactly this). But, I find home made systems typically look terrible. 

I don't know why you'd make one that uses air, and blows it over rocks instead of one that runs fluid and stores the energy in a water tank. Solar air methods aren't as efficient as hydronic, and in summer what are you going to do with a solar air heating system? At least if you heat fluid and store it in a tank you can use it as a pre-heater or use it exclusively for your hot water needs in summer. Just something to think about. And I would get real solar panels (with pipes running through them) not build your own. It was home made jobs in the 80's that failed prematurely from the high temps that almost killed the solar industry. Fiberglass faces clouded and etched in the heat, wood frames expand and contract so much the nails & screws eventually failed to hold them together. Sealing it in a sufficient way against the intense sun of summer is very difficult, and any leaks means condensation. Get yourself a real panel, even a used one if you have to I wouldn't try to build one yourself. I did solar recently for just hot water. I purchased a kit, with the rebates I got afterward I think it cost me the same in the end as going out and buying all the components seperately and trying to build it from scratch. But, I don't get rebates doing it that way. I ended up with a professional system I installed myself, for the same price as probably trying to make one from scratch.


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## hunh?

There are tons of ways to green up your house, even to the point of paying little to no utility bills! :thumbup:

I also saw on another forum how a man built his own solar panel using recycled aluminum cans. I am sure if you google it there is a set of instructions floating around the internet... I am also interested in the wind turbines, but be careful, a lot of trigger happy communities banned them for fear of noise etc. when they were just becoming popular. check with your neighborhood and township before you start that big project. and if they don't allow it, become an activist and get the rule changed! :yes:


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## Red Squirrel

I've thought of solar panels but their watt / dollar is a turn off. I would want at least 1 kw of power out of any solution, that way at least I'm more or less powering the whole house, and only need excess during small time periods, like if I need to use the stove or dryer. 

Though with hot water, has anyone used it to power a sterling engine to then get electricity that way? Is it more effective then just solar cells? There is some loss of energy when going from heat to movement, but is it significant?


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## YerDugliness

Piedmont said:


> Well, I wouldn't do photovoltaics (sunlight to electricity). Sunlight doesn't convert to electricity well, the photovoltaic panels are typically only 11-14% efficient, the rest of the energy turns mosly into heat which is bad for photovoltaics the hotter they get the less efficient and less electricity they make.
> 
> What sunlight does convert well to, is heat. I'm sure you've left a tool in the sun and felt first hand how well it converts to heat. Solar panels that run fluid through them are typically in the 75-80% efficient range, air is not as efficient for transferring the heat.


I've been intrigued by combining PV's and solar heated water in the same panels. I can see PV cells at the bottom of the panel with black ceramic floor tiles on the upper 3/4, used to collect heat and transfer that heat to fluid in copper tubing. I suggested black floor tiles b/c they could serve as a heat sink, thereby extending the useful duration for use of the heat provided by the sun (could there even be a possibility that they could hold enough heat to keep the fluid lines from freezing up at night? That would certainly eliminate the need for an expensive drain-back system :thumbup: ).

I have 8 old solar panel boxes....not much would be of use except for the metal collector "sheet" and the glass, but I wouldn't mind experimenting some when I have time. Who knows, this might just make a big difference in a small structure that is off the grid.

Cheers from Dugly


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## dberladyn

Piedmont said:


> Well, I wouldn't do photovoltaics (sunlight to electricity). Sunlight doesn't convert to electricity well, the photovoltaic panels are typically only 11-14% efficient, the rest of the energy turns mosly into heat which is bad for photovoltaics the hotter they get the less efficient and less electricity they make.
> 
> What sunlight does convert well to, is heat. I'm sure you've left a tool in the sun and felt first hand how well it converts to heat. Solar panels that run fluid through them are typically in the 75-80% efficient range, air is not as efficient for transferring the heat. I'm not sure what you were thinking of doing, I've heard of drilling out the tops & bottoms of soda cans, stacking them one on top of the other, painting them black, and putting them in an insulated case with air blowing in the bottom when the sun is out (cansolair I believe is exactly this). But, I find home made systems typically look terrible.
> 
> I don't know why you'd make one that uses air, and blows it over rocks instead of one that runs fluid and stores the energy in a water tank. Solar air methods aren't as efficient as hydronic, and in summer what are you going to do with a solar air heating system? At least if you heat fluid and store it in a tank you can use it as a pre-heater or use it exclusively for your hot water needs in summer. Just something to think about. And I would get real solar panels (with pipes running through them) not build your own. It was home made jobs in the 80's that failed prematurely from the high temps that almost killed the solar industry. Fiberglass faces clouded and etched in the heat, wood frames expand and contract so much the nails & screws eventually failed to hold them together. Sealing it in a sufficient way against the intense sun of summer is very difficult, and any leaks means condensation. Get yourself a real panel, even a used one if you have to I wouldn't try to build one yourself. I did solar recently for just hot water. I purchased a kit, with the rebates I got afterward I think it cost me the same in the end as going out and buying all the components seperately and trying to build it from scratch. But, I don't get rebates doing it that way. I ended up with a professional system I installed myself, for the same price as probably trying to make one from scratch.


 
I keep dreaming of installing solar panels here but I am glad I've read your post. Thanks for taking the time to write it.


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## HomeInsulation

*Keep the FREE heat*

ThatDaveGuy,

If you have the South Facing wall and a few tools. I say, why not? Even if you don't get it perfect the first time, you're going to learn something and create some free heat.

My thoughts about storing the heat in a thermal mass in your basement...

Insulate your Basement
If you don't air seal and insulate your basement, all the free heat is going to disappear through the walls and holes in your foundation walls before it rises up into your living spaces upstairs.


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## HomeInsulation

*Solar Air Furnace Plans*

BTW - If you are looking for plans or guidance in building a solar air furnace...try this site. http://builditsolar.com/Projects/SpaceHeating/Space_Heating.htm

According to this site, solar space heating is 25 times more efficient than solar electricity. Especially if you DIY,


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## marc novo

I've been working on a few ideas based on propylene glycol


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## marc novo

I've been working on a few ideas; ABS coils heating propylene glycol, filling reservoir and radiating through baseboard style radiators. Runs on thermo-syphon. So far, small scale tests are really encouraging, gonna step it up full scale next week!! Keep ya posted...


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## Red Squirrel

I've been thinking of playing with solar heat as well. It may not be electricity, but heat is one of the major energy uses in a house whether it's natural gas or electricity, so if I could get that part for free, it could make a pretty big difference on the gas bill. 

Is ABS sensitive to the sun like PVC is though? I'm thinking the easiest way would be to just make a zig zag with ABS pipe and then pump liquid through it slowly. Have that inside a small cabinet with a double pane window pointing to the sun.


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## marc novo

I made such a box: I got 65' of 1/2" black abs pipe in a box measuring 3'x2'. I lined it with a couple of black asphalt shingles and hooked up a pressure fit copper coupler to each end as in/output. 

Just pumping through about 5 litters of water, I was really surprised to see the water temp climb to 163•F in just over an hour. I'm going to hook this up to water/radiant baseboard heaters on my 'full-scale' final project. 

The wall thickness of the pipe determines how easily the water heats up; generally, from what I've read, the PVC straight pipe is too thick to do the job very well. I saw an amazing unit where a guy used an oldschool satellite dish with 200' of 1" abs pipe on it, it literally boiled the water in the reservoir!

When I get my unit running I'll post a pic.


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## Red Squirrel

Wow they make ABS pipe that small? Think the smallest I've seen is about 3 inches. I definitely want to try something like this out. Would be pretty nice to have free heat. 

To be able to actually boil the water would be even more fun, but then you probably need iron pipe, which means more tools needed too.


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## marc novo

Maybe I've got my ABS/PVC mixed up? Pipe has ABS on it, but it came in a roll if 100'. Dunno, I just bought what looked like it'd work...


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## Red Squirrel

Oh maybe pex? I think that is very sensitive to sun though... not sure exactly what happens, but I know it's a clear instruction to not have it exposed to the sun. Though, wonder if paint protects it, you'd want to paint it black anyway.


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## marc novo

Only pex I've seen is white; this is black.


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