4 Different Methods for Cooling Solar PV Panels
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- čas přidán 7. 06. 2024
- This video looks at solutions for cooling a solar panel if and when it gets too hot. There are a variety of ways in which PV panel can be cooled. This includes using PCM or Phase Change Materials and also using water sprays. Gallium Arsenide panels can also be used in hot regions.
This video is part of an Online Course on Solar Energy which can be accessed from the following link:
www.udemy.com/solar-energy-te...
For full article on PV cooling follow: synergyfiles.com/2017/01/effec... - Věda a technologie
Thank you very much for your video, I have found exactly the answer I was looking for in your short, concise but precise video. I love people that know how to use the internet correctly, and that is what you have done here.
Thank you for your appreciation. Helps me do more
I like option 3 best with a way of harvesting the heat for heating water. A combined Solar thermal and PV panel, rather than just dumping the heat into the air.
I have developed such a solar thermal panel, without any copper tube exchangers, now on test in Australia and by April 2019 the patent will be approved www.thermaltricity-int.com
This seems like something that could be used in conjunction with concentrated solar either by use of Fresnel lenses or parabolic mirrors. Any thoughts on that?
That is actually the ideal situation, in spite of the extra maintenance it needs. We really need to get manufacturers to add water channels to panels in the factory - just a punched aluminum plate like they use on cheap refrigerators. Renewable electricity generation with free hot water - or at least warmer water that costs less to heat - would cut energy costs for the average 'sun belt' homeowner a lot.
@@alexriddles492 I agree this would be the way to go for a commercial installation. The amount of cooling would make way more hot water than just about any home needs. Using either a lens or a parabolic mirror requires hardware to point the array (or at least the mirrors/lenses) and that hardware and the lenses and mirrors themselves would require a lot of maintenance. It would be a little impractical for a full-home permanent installation.
If you have a swimming pool, you could dump that heat into it
The average insolation (solar energy gain) in southern South Carolina/northern Georgia in August (where I live) is about 5 kWh/m^2 - much less than Texas, Arizona, or especially the Middle East. This converts to 18000 kJ/m^2. The latent heat of fusion of PlusIce is 140 kJ/kg. So you'd need 18000/140 = 128.8 _kilograms_ of PlusIce _Per Square Meter_ ! (over 280 lbs!).
PCM's are great for moderate heat collection over a large area - such as your example of helping cool a desert home during the day and keep it warmer at night. The heat load of trying to cool even one 2' x 4' solar panel (about 3/4 sq. meter) is way over the capacity of any solid/liquid PCM for any practical application. Pumped liquid/vapor PCM's are viable (think heat pipes) but way more expensive - essentially an air conditioner attached to your panels.
Please note that I do understand a smaller amount of a phase change material would keep the panel cool for a set amount of time, and allow higher panel output for that set time. After that, the panel and now liquid PCM would heat up as a unit, taking longer to reach max temperature due to the extra mass and slowing the decline in panel performance. But for any practical fraction of that ideal amount of PlusIce mentioned above, that time would be measured in minutes less than one hour! (Assuming 14 hrs of sun a day, 1 hour would average 1/14th of the solar insolation. 1/14th of 280 lbs is still 20 lbs per panel.) Fusion PCM's (solid/liquid) are NOT a practical way to handle that much heat.
Hi,
Then what do you think is the most efficient method to handle that much heat(from a sub Saharan region)?
@@ahruf Mount the panels so they get as much air as possible. No method of cooling the panels has been found to be worth it when you consider the cost per watt-hour gained outside of extreme environments (space). Water cooling is the closest, but only if you need the heated water - in other words, you need all that hot water for something else, and would have had to heat it with some other method anyway. (i.e. Cooler climates using it to heat buildings.)
Nicely done presentation. Thank you. Would you be able to provide any information on the improvement in efficiency with a spray system? It seems to me that in Brisbane Australia, every day there is a thermal loss of 10-20% due to our temperature range. This is the low hanging fruit for improvement in efficiency. Analysis of 5 years' of data from my own 5 kW system shows that it is highly unlikely that cleaning the panels will make any difference. Aside from heat, the other efficiency killer is the year on year degradation of the photovoltaic cells, which the manufacturer has guaranteed not to exceed 10% in 12 years and 20% in 25 years.
Well done! 😊
thanks for the ideas !
You are welcome
Recent work in Switzerland suggests that placing panels on a green or cool (light coloured) roof will increase the panels' efficiency by between one and four per cent.
Another solution would be to use solar attic fans! Building an open overhead structure for pool area in Florida incorporating 6 mono 350w panels with struts to vary angle with several solar fans with a timer(thermo or hour) for hot periods during summer. Panels will provide shade, fans run on the sun and will also cool guests under it, sounds like a plan to me:) Will try the fans downward and upward under the panels for best results
Goodluck!
I cannot find plans for constructing a solar panel system using PCMs. Do you have links?
Systems based in places like the Sahara desert would benefit from chemical heat absorbers, even a pc water cooler would be a good option, mainly because of the excess heat throughout the year, which lowers the efficiency significantly. In places near the equator, lowering the temperature of PV panels would increase yield, but would also allow us to create something similar to the Noor plant in Morocco, which would probably be way more efficient (sun to electricity + heat, rather than sun to heat then electricity). Producing electricity directly, and removing excess heat from the equation is way more efficient, compared to x times more materials used in converting salt to a molten state. In places with your 'standard' 4 seasons, radiator air cooling using Bernoulli's principle, would be cost effective, as a chemical absorber would be next to useless and expensive compared to a few fans attached to the back, so retrieving the heat would be unprofitable = $/Kwh. Just a thought, if someone has interesting books/articles on chemical absorbers and prices, that would be cool. Anyhow, in a few years time, most, if not all building foundations will be designed with heat storages, to reduce heating costs.
Nice Video😎
I love the water spray solution. But i seems like to pay more for the water consumption. So. What will be the best choice?
sir can you suggest the any detailed research topic for project related to PV cooling
You will find plenty of research articles on it
Can the PV cells be backed by a material that uses the thermoelectric effect to increase the output?
Love to know.
If you get a but load of those chips from China cheap. Place them all over on the back with heat sinks on the other side. You could get more power towards your system I'd think..
The best way to cool panels is to keep them in the shade :) You might think I'm joking, but I'm not. Use selective spectrum mirrors to shine light onto panels which are positioned in shaded areas and angled pointing slightly down towards the ground. Then you can cool the panels from the back using a closed loop water spray or other method. This method has the added benefit of limiting the dust landing on the panels. Yes, you have to track the sun with the mirrors but this is far from impossible. And the mirrors can be cheap, made of reflecting tape stuck on lightweight backer material.
How about creating convection and routing it to a vertical wind turbine that is contained within a shroud? This would probably increase the output efficiency by at least 33%, and I suspect more. During the winter, when you have more wind, you can remove the shroud to get more benefit.
Using Termosolar.
how the PCM material can be applied?
We will be looking to licence our solar thermal cooling exchanger from April 2019, which you can assemble in your own country to any brand of PV panels to create a PVT low cost high performance panel
Good to know
Can I have more info about it.
Any info about it Eric?
A cooling breeze from a fan might be useful.
Air moving under the panels.
3% loss means 3 new panels in every 100 panels, or 1 new panel in every 33 panels. Each year to maintain output and micro inverters.
But micro inverters can degrade aswell.
Option 3 is best
sir good day... very nice video... what is your reference when claiming 30 to 50 years life span if properly cooled?
Thank you. Reference was a research paper on Thermo electric coolers used in conjunction with solar panels.
Synergy Files can we use it as a related literature on our study?
You cannot use the video as a reference. The reference has has to be the original source article. You can search for the article on google scholar. Unfortunately I had the article in my old laptop. The study was carried out in a University in India that much I can remember. If it is a school project, you can use this video as reference
Synergy Files okay thank you very much sir
good day sir, do you have the link of the literature? i cant see it on google scholar. thank you for your response.
Sis sum it up brevity is a skill
Option 5: Mount panels on a Cool Roof, i.e. a roof that is painted a light colour. This will reflect some of the heat away from the panels and make them about 2% - 3% more efficient.
Dear Synergy files
from where we can parchase these little electronic things in pakistan
You can purchase them from electronics market. In Karachi you can get then from Regal near saddar. There are electronics market in most cities in Pakistan. You can also get some electronics from hardware store
Which electronic you want to buy ?
imdad Ali Mahessar which electronic you want to buy ?
You showed how to install the others except the last/4th way. So how to install PCM Packets or Plucise to these already installed panels on residential homes? Can a layer of Plusice or the liquid out of. PCM Packets be coated over the Panels resulting in no damage to the panels or what do you suggest?
i would use method 3 and no pump is needed as the temperature gradient of the water makes it flow on it´s own, this heat is then used to power a stirling engine
What about putting infra-red absorbing glass over the panels? These are sold for domestic windows; why not use them for solar PV?
Shades the sun I'd think
@@NwoDispatcher not necessarily. Some materials are wavelength selective for absorption. Some laser focal lenses used with CO2 lasers at 10600 nanometer, infrared, are above 99% transmissive to infrared but completely opaque to visible light, including what was it 600 nm red pointing laser. Most CO2 lasers do not use that material however because often a pointing laser is aimed through that same focal lens so you can see where the CO2 beam will hit when it is output..
E glass is the name of what is used in windows that appears to have high transmission of visible light but attenuates the IR portion of the spectrum. It would be worth looking in to but you might need vacuum between solar panel and IR panel to stop convection. And the solar panel would warp if you put vacuum on it. I dont think that could be cost effective. And if it were, the high end panels would already be using it for the face glass for that very reason. Maybe that's what those ultra black panels are? If that is the case I dont think you could gain very much compared to the extra cost but over 25 years in an enviroment where 5 degrees lower operating temperature is beneficial it could be worth it, if you want to pay more upfront for the panels.
I'm thinking if you are gonna go to the trouble to try to keep temp down you are gonna have to take heat away from the panel. Think about it, if a panel converts 20% to flowing electrons, the other 80% is some combination of reflected radiation and convection of heat. Lets say 60% is some combination of reflected, re-radiated or convected, that means you need 100 watts of heat removal on a 100watt panel to keep it at ambient temperature. It is going to have to be fluid cooled some way.
Thank you so much for this video ,sir,
But what about Nanofluid Method ?
You can use expensive coolants but at the end of the day, you will still need the cooling jacket.
PV watts
I was wondering why no one is making a solar panel that has a heat exchanger behind it. The efficiency gain is quite dramatic 25% loss is crazy.
Isn't that option 3 as described in the video?
Why not collect the heat and covert to more energy?
Yes that is done is STEG cells
Both paraffin wax or beeswax are good PCM material. Beeswax is better in term of higher melting point... It is important to keep the system temperature lower than the PCM melting point or it will be a disaster.....
Use a thermoelectric generator chips and an aluminium heat sink under the panels to get rid of the excess heat and produce electricity even after the sun has gone down
..what about adding Peltier thermoelectric (TEG) under panels.
Peltier are not very efficient and by themselves only move the heat a small distance. You still have to move that heat somewhere besides beneath the panel, heat rises. Unless the other side of your peltier was liquid cooled you would do more harm than good with the tremendous wattage you would be burning in the peltier units. Just figure up what a whole solar panel covered with peltier units would cost, no need to pursue that further.
@@laserflexr6321 ..thanks for clearing that up..mybe it would work for a few moments..later when the heat is equal than the difference between hot & cold becomes smaller.. that's would not work very effectively..tq for the reply
Instead of removing heat after sunlight hits PV cell, what if we can block/filter the thing that makes the PV cell heat up? The cell used the photons of light to create electricity, right? Our sun is blasting the full spectrum of light. Seems the PV cell doesn't need the full spectrum to generate electricity?
True. We need in silicon PV we need photons with energy of 1.3 ev. Rest arent used up and result in heat. New PV panels make use of photons with multiple bandgap energies. Please see multi junction solar cells
The plants I touch never seem to be "too hot" so they figured out how to convert sunlight to energy without overheating...keep on thinking!
@@loucinci3922 plants use water
Just cooling my panels with a water increases amperage 7amps 24 volt system
What about combining the solar panel with a STEG system. Using the heat from the panel to power the peltier modules.
TEGs have very poor efficiency even for high performing units. they are very expensive due to their relatively low production volumes (mostly small gadgets and hobby makers.) It would also act as an insulator, preventing the panel from dissipating heat, and on a hot day would itself (the TEG) become heat soaked and progressively decrease output, while still insulating the panel.
It's a good idea, but until there are some significant materials tech advancement in the area, the feasibility for TEGs as heat harvesters is low.
Would a layer of aluminium glued to a flexible panel act as a heat-sink?
It would but the glue should be a thermal compound and hink sink should be exposed to moving air
It will be elevated of course to allow the air to move behind it freely. I don't know of any thermal compound that will be economical for such a big job, so I thought a glue mixed with a HEALTHY DOSE of fine aluminium shavings may do the trick...
Just add a big heatsink in the back like a CPU
Wouldn't a heat absorber 'under' the panel be useless in protecting the cells in direct contact with sunlight?
The longest that panels need to last is 10 years if the installation isn’t big and 20 year’s for bigger installations, because after 10 years you can replace 6 or even 20 panels with more advanced panels, because technology advances quickly
solar panels indoors behind the window benefit from in-home cooling.
Great explanation except the spraying of water idea in countries with a water crises, mainly hot countries
When you say a solar thermal is expensive, what do you call expensive when many comercial companies use millions of liters of hot water a year?
I did mention that cleaning of solar panel with water is not environmentally friendly. This practice however has caught the wind unfortunately and is being used in many areas around the world. I am all for solar thermal technology. All economizers in hot climate countries should be solar
Looking forward to hearing your views on what is the cost of expensive, when you related to PVT hybrid solar panels? I have designed and developed a thermal cooling package kit, you can assemble yourself and retrofit to any PV brand in the world up to 300 watt sizes. I just shipped 28 kits to an Australian, to fit to his 28 LG 300 watt panels to heat his swimming pool. My cost to him was $165.00 per kit plus shipping
I now have a PV EPC provider in Mexico who wants to acquire the exclusive rights to my thermal cooling panel kits in Mexico with a office in the USA over the border of the Ba Ja. To other such players in the selling and installations of PV systems, larger than 10kW, with space for a large PVT developed flat pack tank (also assembled on site) to make sure the heated cold water does not increase above 30c, then feel free to contact me. My office is in Hong Kong, product shipped out of China, with, or without the PV panel, now as low as $0.34 cents a watt, contact me
@@erichawkins3915 Hi Eric, I'm interest in your product. Could you please contact me for more information at chanin.s@primeroadgroup.com
Why not put an umbrella over them to shade them from the sun?
Haaa. With water sprays
Yes solar panels are also be covered by Shadow nets and jute bag...
PCM filled coolers (placed under the panels) become too hot after just 30 minutes or so of full sun. The solution doesn't work at all! 🙃
Instead of 20-25% efficiency, wasting solar heat, use water cooling to collect heat. PCM is a waster, unless the heat is used.
We developt option 5, please let us talk about it:
What if using peltier...
could work, but they are also extremely power hungry. one small 40x40mm peltier plate can easily swallow up 50 to 100 watts of power.... but using them to generate a little extra energy through the seebek effect (as in teg's or thermoelectric generators?) that might work.... in theory.
Got it now, thanks alot for the good advice.
0:48 you mixed up Temperature and Effiency in your diagram.
Solutions start at appx 1 minute 22 seconds (1:22).
Use water of a swimmingpool to cool panels and then heat the pool.
5: keh ALLAH say DUA karain keh soraj be ho aur Barish bhi bersy teb khob AMP daytain hain........
2 3 dafa aisa yahan howa tah
.saeed from Peshawar
ha ha ha ha
Why not use aluminium pipes? They are cheap. Why not float the panels in a canal that has moving water? With this system you will collect hot water also.
Sir l have personal experience that when we put cold water on hot glass. it cracks. same happen to solar panel. water spray can damage panels.
Safdar Karim you dont have to put cold water. Normal water at 20 to 30 degree should be more than enough. Your solar panel temperature goes up to 70 degrees. So with that differential, it would be difficult to crack glass
The survival of solar panels in conditions involving constantly repeated rain downpours as happens in summer in Australia, does not support your theory. The glass on modern solar panels is toughened and designed to withstand the extremes of climate including snow and rain and the panels I purchased in 2012, are designed to withstand 5 kPa UDL.
I sugested this to my California freind who contacted me about his PV panels over heating, and my sugestion about useing his garden hose pipe to prove my point, worked without the toughend glass cracking
What is already happening in very hot countries, even happened last year in the UK, is the wafers start to crack.
A PVT solar panel is about cooling the back of a PV panel at the lowest cost to improve PV efficency as well as gaining a by product of heated water to 30c, for use as a Pre heat back up by a water to water heat pump.
Only recomended for use in commercial applications like the food and drinks industry to fish farms and Aquponics
@Synergy Files if you read the complete maintains manual of pv panel .It said that water you put on panel must have maximum 25% temperature difference .Otherwise glass can be damaged. So in very hot regions like Pakistan,Saudia its better to consider this factor while designing cooling system.
With glass for PV panels made of toughen glass, I have no experience of cracking glass.
I have developed a solar thermal panel you place behind the PV panel and pump cold water across the heat exchanger at the back and this increases total energy output per panel of 3 times as much
It's a good topic for a video but none of the solutions you have shown are viable.
2nd option waste the water
Simple over view. Thin film and say nothing else. The only thing I know is that it has less thermal mass so heats up faster. Still something has to carry the heat away. None indicated. Natural convection from the faces. Well the area is the same and basically independent of thickness. Thermal resistance of natural convection is far worse then the conduction resistance. This is an incomplete solution.
Spray cooling. The water will absorb some frequencies. Will reflect some light away better then the well designed face of the cell and finally the water contains dissolved minerals that will be left as the water evaporates in the process of cooling.
Liquid heat sink of a flowing liquid or the phase change material. I am combining them. Both require a surface to make contact with the solar cell. This near solid aluminum heat sink approach is what I would use for more then 1KW / sq meter. that the sun heats, a lot higher. use the approach of the next approach, phase change. Plastic works in that application so the liquid could be a low pressure and wet the whole face through the film of a bag. The heat can be used for thermal storage in a more cost effective material and be insulated so more control is obtained. Green houses use the earth around the plants and under the green house. Lots of choices since volume, weight, and conductivity is not as important.