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Old 20-06-2022, 16:38   #1
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Water cooled solar panels.

Boats are surrounded by water.

Why not pump up some water to cool the back of your solar panels?

Would the power to the pump use up all the efficiency gain?
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Old 20-06-2022, 16:46   #2
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Re: Water cooled solar panels.

Oh my god, why didn't I think of that??

What an awesome idea, and salt water would be best right, so the salt crystals magnify the suns rays....super efficient, super coooool!!
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Old 20-06-2022, 17:16   #3
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Re: Water cooled solar panels.

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Oh my god, why didn't I think of that??

What an awesome idea, and salt water would be best right, so the salt crystals magnify the suns rays....super efficient, super coooool!!
Must have missed "back of the panel".

When reading, comprehension is the key to understanding.
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Old 20-06-2022, 17:24   #4
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Re: Water cooled solar panels.

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Must have missed "back of the panel".

When reading, comprehension is the key to understanding.
Probably the quickest way to destroy the panel and just great for the rest of that part of the boat where the water would constantly cascade on its return to source.
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Old 20-06-2022, 17:28   #5
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Re: Water cooled solar panels.

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Must have missed "back of the panel".

When reading, comprehension is the key to understanding.
The key to understanding.....having built solar panels I know what the back of them looks like ,and they will not be happy wet, so perhaps the key to understanding is a thought process.
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Old 20-06-2022, 17:44   #6
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Re: Water cooled solar panels.

Apparently from comments, no one has thought of passing the water through cooling coils on the underside of the panels.
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Old 20-06-2022, 18:04   #7
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Re: Water cooled solar panels.

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Apparently from comments, no one has thought of passing the water through cooling coils on the underside of the panels.
Well to be honest I thought the OP was a joke.

Stop for a moment and think about it, pumping salt water up between 5 and 15 ft to to remove heat from the back of solar panels....by conduction?....through coils or direct contact? or through an air gap? (to reduce corrosion)to improve efficiency by what unknown percentage?

Yes, definitely a joke.

Either that or daydreaming on a couch a long way from a boat....and salt water....and solar panels.....and reality.

I will leave you to it.
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Old 20-06-2022, 18:54   #8
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Re: Water cooled solar panels.

We pump salt water through metal tubes all the time -- engine heat-exchangers for example. You could glue the metal tubing to the back of the panels and get significant thermal transfer. This would work to cool the panel and increase the power output.

The question isn't the reliability, it's "will the power gained exceed the power needed to run the pump?" Which is what the OP was wondering. It's a good question. I don't know the answer, but I assume it depends on many factors, including water and air temperature, amount of sunshine, pump efficiency, etc.
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Old 20-06-2022, 19:01   #9
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Re: Water cooled solar panels.

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We pump salt water through metal tubes all the time -- engine heat-exchangers for example. You could glue the metal tubing to the back of the panels and get significant thermal transfer. This would work to cool the panel and increase the power output.

The question isn't the reliability, it's "will the power gained exceed the power needed to run the pump?" Which is what the OP was wondering. It's a good question. I don't know the answer, but I assume it depends on many factors, including water and air temperature, amount of sunshine, pump efficiency, etc.
Yes yes, absolutely...

Sorry my bad. Continue, please. Much to ponder.
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Old 20-06-2022, 19:30   #10
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Re: Water cooled solar panels.

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Yes yes, absolutely...

Sorry my bad. Continue, please. Much to ponder.
I too have to plead guilty to assuming that it was a joke, however to achieve a realistic heat transfer I guess one would need something like a refrigeration evaporator plate (obviously not aluminium) bonded to the back of the panel with water pumped through it. This poses the question, should the cooling water be connected between panels in series, thus providing less cooling to the last in the string, or would parallel be required.
Then the operating power consumption, would the load outweigh the benefit?
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Old 20-06-2022, 19:32   #11
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Re: Water cooled solar panels.

Most basic issue: Does the improvement in solar efficiency (and thus solar power output) outweigh the cost of pumping the coolant? Not even including issues of component lifetime, biofouling, etc etc.
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Old 20-06-2022, 19:53   #12
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Re: Water cooled solar panels.

This issue has actually been studied to death. In general it has not been found to be cost effective, but it is still the second holy grail of the industry (after increasing module efficiency).

https://www.osti.gov/servlets/purl/1617289

https://link.springer.com/article/10...56-022-18719-9
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Old 20-06-2022, 20:17   #13
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Re: Water cooled solar panels.

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Originally Posted by HeywoodJ View Post
This issue has actually been studied to death. In general it has not been found to be cost effective, but it is still the second holy grail of the industry (after increasing module efficiency).

https://www.osti.gov/servlets/purl/1617289

https://link.springer.com/article/10...56-022-18719-9

Interesting reading. From the second link:
"Colţ (2016) conducted an experiment to cool the photovoltaic by circulating water at its rear surface. In his setup, he used an aluminum radiator as a heat exchanger to extract the heat from the photovoltaic, as shown in Fig. 10. The results indicated that the photovoltaic surface temperature decreased by 32%, and the electrical efficiency increased by 57%." [empaasis added]
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Old 20-06-2022, 20:31   #14
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Re: Water cooled solar panels.

Thank you.

I was thinking of bonding a copper or aluminum board, maybe similar in shape to corrugated plastic board, so that the small channels of flowing water would cool the cells. Sort of like a radiator, but a surface cooling effect instead of airflow.

I did not think if bio-fouling, which would be an issue.

Typically, my ideas are either already available, or three years ahead of current availability.

Look for this efficiency improvement in about 3 years.

Oh, by the way. Salt water? What about the Great Lakes? Fresh and cold water. See it there first.
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Old 20-06-2022, 20:37   #15
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Re: Water cooled solar panels.

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Originally Posted by StuM View Post
Interesting reading. From the second link:
"Colţ (2016) conducted an experiment to cool the photovoltaic by circulating water at its rear surface. In his setup, he used an aluminum radiator as a heat exchanger to extract the heat from the photovoltaic, as shown in Fig. 10. The results indicated that the photovoltaic surface temperature decreased by 32%, and the electrical efficiency increased by 57%." [empaasis added]
Interesting, Maybe, but still total BS. What EXACTLY does it MEAN that "electrical efficiency increased by 57%"???? Can you explain that? Can you calculate it? Can you tell me how much extra power was generated?

Do you realize that energy output did NOT increase by 57%?? Because IF that was true, that's what they would have said. Actually I KNOW that wasn't true... because the temperature coefficient of a solar panels is around -0.3%/ºC. To increase power output from a standard solar panel by 57% you would have to cool it from almost 200ºC to 25ºC. I think not... unless you are keeping your solar panel in your oven...

This is a CLASSIC case of misleading by being murky in terminology. Making something sound like an amazing discovery, when it is a really a total nothing burger. Because if you don't you'll never get that next research grant.

Take note of this, everybody who complains about the people on here who can be a bit pedantic about using units correctly. This is why.
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