DIY Solar Pool Heating: Can You Just Focus A Big Lens On Your Pool?

Treehugger:

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[jeg]

Ok, here's the DIY solar heater for your pool. It's cheap, it's affordable, and with little effort, can raise your pool from "chilly" to "uncomfortably hot" very, very quickly.

Painting, first off, is a terrible idea. You're not heating the water, you're heating the material the pool is made out of, and you're doing it poorly.

Go down to Ye Olde handyman shop, and get a roll of black plastic, wide enough to cover the pool. Unroll it, letting the plastic float on the water, anchor down the corners with rocks or some such. Now... turn the filter off. Within a few hours, you'll have a layer of warm (or possibly hot) water at the top. Turn the filter on to mix it in. Repeat until pool reaches desired temperature. Remove plastic and enjoy.

Typically, it required a full day of sunlight to raise our pool from the low 70's to the low 80's.

There are better methods, including an actual rooftop solar heater with pipes built into your filtration system, but few methods are cheaper.

[chris2fer]

Check out the pic of the kids remember frying bugs with a magnifying glass? hahahaha.

[research]

The DIY Solar panels article is excellent. If you by the 60 cells for 20$ as they did, and get 50Peak watts.

If you scrounge all the rest of the parts you can build panels for say 30$/50 peak watts, your pay back is less than two years.

[KillTheMessenger]

The only problem is that your panels will not work that long unless you have a thorough understanding of material sciences and soldering processes, not to mention quality control.

And where can I buy 60 new, undamaged cells for $20? I have not seen scrap cells go for that much. Usually they are broken and a rip-off.

[research]

Silver Solder and silicone should work very well for decades.

Obviously if you can't get the cells cheap, there is now point.

Even at 1$/peak watt, the pay pack is less than 4 years. 1 year in NYC.

http://cgi.ebay.com/36-Barely-Broken-3X6-Solar-Cells-Photovoltaic-Panel_W0QQitemZ230310212201QQcmdZViewItemQQptZElectrical_Solar_US?hash=item230310212201&_trksid=p3286.c0.m14&_trkparms=72%3A1205|66%3A2|65%3A12|39%3A1|240%3A1308

[The Hedonistic Pleasureseeker]

Proof that this website is for yuppies. Your pool. Your POOL. Maybe you should empty your pool and turn it into a sunken garden instead.

[jeg]

You know what the healthiest form of exercise in the known universe is? SWIMMING. There's no other way to stay fit that puts less stress on your body.

[newshawk14]

Having the pool painted with a radiation absorbent paint makes sense, and you would want a
thermal cover for the pool at night to retain heat. Unless the fresnel lens is larger than the pool
there would be no net gain.

[KillTheMessenger]

If you had a Fresnel lens that's larger than a pool, I would run and take cover as soon as the sun rises...

:-)

[FatherWolf]

"Unless the fresnel lens is larger than the pool there would be no net gain."

Bingo. A Fresnel lens doesn't create solar energy; it just concentrates the energy on a smaller spot.

However, you might use a Fresnel lens to take advantage of some non-linearities.

Radiation-absorbent paint on the bottom of the pool will heat up the earth underneath as well as the water above. A heat-absorbing object above the surface (like the metal heat sink in the video) will transfer more heat to the water rather than the earth. A Fresnel lens could concentrate solar energy from a large area onto a relatively small heating object. However, would probably be more effective overall just painting the entire bottom of the pool a non-ugly dark color.

[newshawk14]

The thermal conductivity of water is so high, that it would tend to swamp out
most of the effects that you refer to. It would probably make sense to do an
analysis if one could lessen the thermal conductivity into the ground and keep
more latent heat in the water. Simple large sheets of bubble pack would tend
to keep a large percentage of the heat in the water, and be lightweight enough
to be easily rolled up when you actually wanted to swim.

[KillTheMessenger]

This one gets the price for the geekiest article of the day. Large Fresnel lenses are tons of fun, though...