Chris Hobson Posted January 19, 2017 Share Posted January 19, 2017 I came home today and tried a little experiment. I was changing over which flower beds get watered and decided to quickly wet the panels and see whether it had an effect. The effect was immediate and on a 3kW array production rose by about 200W. I am not planning to make a cooling system - water is more precious than sunlight but it goes to prove that panel temperature has a significant impact on production. Hannes7212 and superdiy 2 Quote Link to comment Share on other sites More sharing options...
DownTime Posted January 19, 2017 Share Posted January 19, 2017 56 minutes ago, Chris Hobson said: I came home today and tried a little experiment. I was changing over which flower beds get watered and decided to quickly wet the panels and see whether it had an effect. The effect was immediate and on a 3kW array production rose by about 200W. I am not planning to make a cooling system - water is more precious than sunlight but it goes to prove that panel temperature has a significant impact on production. A client of mine extended his garden irrigation pipe onto the roof, put it under the panels and had a small sprayer between each panel. Summer time when his wife cleaned the house and used the vacuum cleaner he would put the water on and it would cool the panels down and produce more power. The panels produced up to 300W more every time he did it. superdiy and Chris Hobson 2 Quote Link to comment Share on other sites More sharing options...
Noobie Posted January 19, 2017 Share Posted January 19, 2017 Very interesting Probably best to mist the underside of the panels as a long term effect of misting would be lime scale build up on the glass causing a reduction in output power Quote Link to comment Share on other sites More sharing options...
ebrsa Posted January 19, 2017 Share Posted January 19, 2017 You have my sympathy Chris. Right now (16:25) the temperature in the sun is 30C but the wind chill of the southwester straight off the ice cold Atlantic brings it down to 21C. It blows right onto the back of my panels which are at 30 degrees angle on a flat roof. We may not be too keen to jump into the ocean for a swim without a thick wet suit but it sure must improve generation by the panels. At least one advantage of the wind in summer on the West Coast apart from Mike Thorne having his wind generator doing just fine generating power for all his Bitcoin miners. Quote Link to comment Share on other sites More sharing options...
Chris-R Posted January 19, 2017 Share Posted January 19, 2017 Chris, excessive heat on the panels and cold water in your geyser? Would be nice if someone can get a way to extract heat from the panels and put this into the water in some or other way? Quote Link to comment Share on other sites More sharing options...
Neo Posted January 19, 2017 Share Posted January 19, 2017 The panels exist, they are called hybrid or PV-T for PhotoVoltaic -Thermal. Quick google graphic for claimed performance.. Quote Link to comment Share on other sites More sharing options...
Guest Posted January 19, 2017 Share Posted January 19, 2017 I tried, did not work so well ... Quote Link to comment Share on other sites More sharing options...
Guest Posted January 19, 2017 Share Posted January 19, 2017 Here they are: http://coolpvsolar.com/ Quote Link to comment Share on other sites More sharing options...
Mark Posted January 19, 2017 Share Posted January 19, 2017 I tried, did not work so well ... Nice panels...[emoji12] Sent from my SM-G800F using Tapatalk Quote Link to comment Share on other sites More sharing options...
Chris Hobson Posted January 19, 2017 Author Share Posted January 19, 2017 33 minutes ago, The Terrible Triplett said: I tried, did not work so well ... 2 minutes ago, Mark said: Nice panels... Sent from my SM-G800F using Tapatalk Where can we order some of these from Jay? superdiy 1 Quote Link to comment Share on other sites More sharing options...
Don Posted January 19, 2017 Share Posted January 19, 2017 7 hours ago, Chris Hobson said: The effect was immediate and on a 3kW array production rose by about 200W. Damn, with water restrictions I cannot even water my garden. Now it seems I have to water my solar panels as well, lol. Chris Hobson 1 Quote Link to comment Share on other sites More sharing options...
subok01 Posted January 19, 2017 Share Posted January 19, 2017 I have even experienced this effect with 180w panels strapped to my roofrack. Measured AxV when driving in full sunshine, but SE breeze is up by about 10% as opposed to being stationary on the leeway side of our house.Sent from my SM-N910H using Tapatalk Quote Link to comment Share on other sites More sharing options...
Chris-R Posted January 19, 2017 Share Posted January 19, 2017 2 hours ago, The Terrible Triplett said: I tried, did not work so well ... I am sure excessive clothing is the cause of the poor performance! superdiy and Chris Hobson 2 Quote Link to comment Share on other sites More sharing options...
Don Posted January 20, 2017 Share Posted January 20, 2017 So I imagine in 2-3 years time, we will all be replacing our panels with the all "New and Improved" super duper water cooled panels. Chris-R and ibiza 2 Quote Link to comment Share on other sites More sharing options...
Czauto Posted January 20, 2017 Share Posted January 20, 2017 Not sure if your panels are at a fixed degree tilt or if you can adjust it with season change. I'm still experimenting with my tilt angle. I designed my frame so I can adjust it with season changes to always be 90deg angle with the sun. Big mistake. My roof is at 21deg which was supposed to be the summer angle. I changed the angle one day to put some wiring in trunking (have to lift it to get underneath) and saw that at about 39deg, I was producing up to 120W more with my 6 x 250Wp panels. I was now constantly putting out 1390W - 1420W on a good hot sunny Karoo day with temperatures running in the high 30's to low 40's. I dropped it down to 21deg again and within 10mins I was getting only 1300W. I know this sounds stupid but I've got a theory about it. Firstly, when at a greater tilt, there is more airflow underneath the panels, cooling them. Secondly, with a greater angle and the sun not exactly 90deg with the panels, power generation decreases, BUT (and this is the theory part) at the greater angle, the panels are not heating up so much. This is because the UV rays are deflected from the panels slightly and with that also deflecting some off the heat. The trick is to find the sweet spot where they are the coolest while getting maximum sun. I want to get up there one day and measure the panel's temperature at different angles but this would have to be done at roughly the same time of day, without any clouds and preferably without wind. This is the only way I can test and prove my theory. Seeing that we're having cloudy and windy condtions most of the time these days, I haven't been able to get the testing conditions perfect. I did however try the watercooling thing once. 1630Wp with 1500Wp array. Not too shabby. LOL Anyway, back to the point. Try some angle changes if possible. You might be surprised with the results. Or you can always add a panel or two to compensate. Me? I'm trying to see what I can get out of mine before I add more. Next is a solar tracker. Still in the designing stage of that............. Quote Link to comment Share on other sites More sharing options...
subok01 Posted January 20, 2017 Share Posted January 20, 2017 So infinitely adjustable as in solar tracker with a 'summer' offset? Ther may be some doctoral thesis on that. I will enquire from my Stellenbosch contacts and let you know if I find anything worthwhile.Sent from my SM-N910H using Tapatalk Quote Link to comment Share on other sites More sharing options...
Czauto Posted January 20, 2017 Share Posted January 20, 2017 There might be a lot of technical explanations and debates arising from this. Only sharing what I found. Still new in the solar game.....Sent from my S60 using Tapatalk Quote Link to comment Share on other sites More sharing options...
Chris Hobson Posted January 20, 2017 Author Share Posted January 20, 2017 1 hour ago, Czauto said: Not sure if your panels are at a fixed degree tilt or if you can adjust it with season change. I'm still experimenting with my tilt angle. HI CZAuto. I am going to be in your part of the world in March and I would like to come look-see. I have a ground mounted array and change the tilt seasonally. 10 degrees summer, 29 degrees autumn spring and 45 degrees winter. I have a reasonably efficient system but tweaking it would be fun. Quote Link to comment Share on other sites More sharing options...
Czauto Posted January 20, 2017 Share Posted January 20, 2017 Hi Chris, Mine is a simple late afternoon built frame welded together from 50mm square tubing and 32mm angle iron. All i've done is put some 100mm bullet hinges on the bottom side. At this stage I still have to pick it up on top and put in some variable lenghts of square tubing to support it (to alter the angle facing true North). This is not a permanent mounting frame seeing that I'm still experimenting with angles and are planning a 2 axis solar tracker to mount a total of 12 x 250W panels(I have only 6 at this stage). At first I had a solaire direct 3KW grid tied inverter but soon decided to get rid of it and replace it with a Axpert 5Kva MKS. The build was done on a tight budget so for now I have 4 x 105Ah Energizer Sealed Lead Acid batteries connected. This together with a BMV-700 and ICC software connected through a Raspberry Pi3 is doing wonders for my electicity account. I'm Running grid power through a Prepaid meter and the Axpert succesfully handles the overloads, etc. With such a small battery bank I run my Swimming pool pump for about 4 hours a day to consume the electricity produced by PV. ICC switches supply over to grid when batteries reach 70% SOC.ew whole solar system cost me less than R30k. The Stove and geyser is LPG and water is supplied from a borehole pump (0.32kw) into a 2500Ltr storage tank and then Pressurised by a Pascali booster pump. Everything has been done by myself and is not perfect, but it's working and that's all that counts. You're welcome to come around whenever you like. I work out of my backyard so I'm available most of the day...... superdiy and Chris Hobson 2 Quote Link to comment Share on other sites More sharing options...
SilverNodashi Posted January 21, 2017 Share Posted January 21, 2017 On 1/19/2017 at 1:51 PM, Chris Hobson said: I came home today and tried a little experiment. I was changing over which flower beds get watered and decided to quickly wet the panels and see whether it had an effect. The effect was immediate and on a 3kW array production rose by about 200W. I am not planning to make a cooling system - water is more precious than sunlight but it goes to prove that panel temperature has a significant impact on production. I have measured 69 degrees, underneath my panels last week! And it hasn't even been as hot as in 2015 yet. Also planning on building some sort of cooling system but don't yet know what to build, since, as you say, water is precious. Quote Link to comment Share on other sites More sharing options...
SilverNodashi Posted January 21, 2017 Share Posted January 21, 2017 On 1/19/2017 at 8:05 PM, The Terrible Triplett said: I tried, did not work so well ... are you the one with the yellow top? Quote Link to comment Share on other sites More sharing options...
SilverNodashi Posted January 21, 2017 Share Posted January 21, 2017 On 1/19/2017 at 5:15 PM, Chris Rossouw said: Chris, excessive heat on the panels and cold water in your geyser? Would be nice if someone can get a way to extract heat from the panels and put this into the water in some or other way? Well, if you use copper pipe, right underneath the panels, it would draw out some heat. Perhaps glue them on with a thermal paste. Problem is, since they're round, they may not work as effective, but it will draw some heat out. would be well worth experimenting? Quote Link to comment Share on other sites More sharing options...
___ Posted January 27, 2017 Share Posted January 27, 2017 There is a Spanish heat-pump product with an absorption plate thing that you can mount below your PV panels. I can't seem to find it now, but there are local people selling them. I think its around a 500W heat pump, you get a better COP because of the collector plate (which you put in the sun, or under your PV panels if you have them). Quote Link to comment Share on other sites More sharing options...
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