Water mist cooling for increased panel efficiency?
2twisty
Solar Expert Posts: 199 ✭✭✭
I know that panels lose efficiency as they heat up. I know that cooling the panels has been discussed and it's been concluded that the power gains wouldn't be worth the power expenditure to cool them.
I got this hare-brained idea the other day when washing the dust off my panels.
What about evaporative cooling? I live in the West Texas desert where it is VERY dry (<16% humidity, my digital hygrometer only goes that low), and very hot (105F yesterday). A periodic gentle water mist would cool the panels substantially, no? I'm not talking about flowing water on them, but just a mist to cool them off.
If feasible, would there be risk to the panels from water droplet lensing effects or should the water mist be applied to the back of the panels?
I got this hare-brained idea the other day when washing the dust off my panels.
What about evaporative cooling? I live in the West Texas desert where it is VERY dry (<16% humidity, my digital hygrometer only goes that low), and very hot (105F yesterday). A periodic gentle water mist would cool the panels substantially, no? I'm not talking about flowing water on them, but just a mist to cool them off.
If feasible, would there be risk to the panels from water droplet lensing effects or should the water mist be applied to the back of the panels?
Comments
Water on solar panels does creates lensing and reflective effects--And I do not know if that reduces panel output or not. On my house (105 degree days are vary rare here), I tried cooling my roof top panels with water on my Grid Tied system, and I did not really see any noticeable effect.
In the end, get 10-20% more solar panels (one time expense for not much money) and avoid the wet array.
-Bill
Temperature cycling is how you damage things when you want to test for a failure point.
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If you could run cold water through a heat exchanger on the rear of a solar panel--Yes--You could have increased power output and increased life.
However, the cost/complexity/power required to run pump/water leaks/weight all add to the downside. A decade ago, panels were $10 per Watt. Today, they are less than $1 per Watt. It is not (in my ever so humble opinion) to build $10 per Watt panels (not even a SWAG) panel cooling system to extend the life of a solar panel by 2x and 10-20% increase in electrical output power.
Get good quality "glass" panels--And they will last you 20-40 years pretty easily. And if/when they fail, replace at $1.00 per Watt.
If you still want to look at water "cooled" solar panels, you can check out Sun Drum:
http://www.sundrumsolar.com/products--services.html
From my point of view, they do not really "cool the panels" for increased power output/life--But are doing secondary thermal solar collections under the solar electric panels (pool heating/domestic hot water/etc.).
Perhaps a good idea if you have limited space for solar panels--But otherwise, would not be my first choice.
-Bill
Since adding panels for me is expensive (I have to buy them in groups of 3), I was looking for a way to eke out a bit more efficiency during the time of year that I consume the most energy.
There is a lengthy (and heated) discussion of this over on SolarPanelTalk.
https://www.solarpaneltalk.com/forum/solar/solar-energy-facts/18035-water-cooled-solar-panels-for-significant-output-boost
I'm still reading it, but the consensus I'm getting is:
I'm going to continue to read the thread. I may give it a try if the costs aren't too high in terms of materials. I'm thinking to mist the underside with either sprinkler system parts or those vegetable misters you see in the produce section.
Your point about thermal cycling is a good one. So far in the thread mentioned above that has not come up... I will certainly add that to my deliberations. I don't want to harm the panels, that's for sure!
--vtMaps
The "good ones" would not fail even in 1 month of cycling.
-Bill