increase static solar panel efficiency/output?

jimmyhackers

10 kW
Joined
May 11, 2015
Messages
600
im looking for ways to potentially increase my static solar panels power output.
they are on a sloped roof facing south east.

i had the idea of using solar reflectors(mirrors) to focus more light onto them, but this seems unpractical.

is there some kind of light redirecting film that would mean more light is hitting them directly?

or anything else??

thanks in advance
jim
 
jimmyhackers said:
im looking for ways to potentially increase my static solar panels power output.
they are on a sloped roof facing south east.
i had the idea of using solar reflectors(mirrors) to focus more light onto them, but this seems unpractical.
That will work. But at Carrizo that resulted in overheating the panels and they all turned brown (the EVA was damaged) thus reducing their output. Also, that generally requires tracking.

Other options:

-Cooling them will increase output, but active cooling always takes more power than is gained. Clever ducting to take advantage of wind might work.

-Frequent cleaning will increase output by a few percent.

-An MPPT charge controller will give you better performance than a PWM controller (of course.)
 
Take them off the roof and pole mount them. They will produce measurably more power, being in "free air"/running cooler. And, if you get snow, and have a tilt mount, you can get a double whammy on a sunny winter day by picking up some rays bouncing off the snow. The highest output possible will be of course when its cold, but the double refraction from direct sun and snow bounce will be even higher.
 
Previous comments are correct. Keeping our panels, clean and cool, using MPPT and tracking are the only ways to maximize your panel efficiency. Yes, mirrors concentrated onto the panels will increase your output, but you have to constantly adjust the mirrors, otherwise they will shade the panels quickly and reduce your output.

If there was a cheap and easy coating or something, all the manufacturers would be doing it.
 
All the concentrators I've seen require a spacing between the lens and the cells, need to track, and use small cells separated by relatively large distances. I think pretty much anything you try to add to an existing setup will end up costing more per kwhr than simply buying some extra panels.
 
I'll add one more trick (applicable if you don't already have the panels) -

Use bifacial panels and mount them on a frame or tracker with lots of white space behind them. Bifacial panels will collect energy from both sides, so reflected light will be used as well.
 
thanks so much for the replies everyone, they have been rather helpful.

there are 2kw of solar panels on a 45 degree sloped roof facing SEE (south east east) they are spaced off of the roof on their frame by about 5-6inches. this is on the roof of a normal 2 story house in the UK

they rarely reach maximum wattage output though the most ive seen is about 1.65kw from them.

my initial idea was a few fixed mirrors in my front garden to give the panels a bit more juice in the afternoon when the sun's lower on the wrong side of my roof. with this itd be pretty easy/cheap to install (i could diy it) and due to its rudimentary/poor design it would negate overburning the panels.

from your replies though i doubt there is much i can do that would cost less than just adding more solar panels.

keeping them cool was something i hadnt thought of/know about, however im not sure how effective adding ducting would be.

sadly there is no more space on that side of the roof. on the other side are 3 skylight windows into the loft. meaning id need probably 3-4 seperate frames to hold them all. plus the whole ball ache of paying someone to do so.... scaffolding etc etc.

plus as this new array would need a new inverter as they are pretty much at a 45dgree angle facing NWW and im guessing wouldn't work very optimally linked into the old solar string array.

i could quite easily fit about 120watts of "flexible" panels onto the skylights/windows. seeing as they are movable i could work out some sort of limited tracking for them (opening the windows at the correct angle :p).
i know fitting panels behind glass is a big no no due to heat....but maybe a bit of spacing and the poor uk weather would alleviate this. ive had a crappy 12watt panel set up this way for years, charging a battery for my lights in the loft conversion and its been fine.

ill do some more investigating and see what is within my grasp. (i was thinking about getting a small wind turbine instead :p but im not to sure about planning permission nonsense etc)
 
jimmyhackers said:
sadly there is no more space on that side of the roof.
Hang them on the side. Vertically mounted panels still produce over half the power that a properly mounted panel would, and are easier to mount. (And very easy to keep clean.)
i was thinking about getting a small wind turbine instead :p but im not to sure about planning permission nonsense etc
I have never met anyone who had any success with those. Unless you are going to mount them correctly (which means on a pole, so the lower edge of the rotor is 30 feet higher than the nearest obstruction within 500 feet) you won't be happy. And if you mount them on your house you _definitely_ won't be happy - those things transmit a lot of vibration.

Can you get a 100+ foot pole around your location?
 
e-beach said:
What’s better than one pancake? A whole stack of pancakes! Using the same logic, a team of MIT researchers have stacked a bunch of photovoltaic solar cells together to produce up to 20 times the power output of conventional solar power installations.
Hmm. Modern panels are 18% efficient. So these would be - 360% efficient?
 
Mirrors are a good idea.

It will take not much time and your cells will develop hotspots because of the mirrors concentrating light unevenly on them and some cells will see reverse current and additional heat thats extra heat to the additional heat from the mirrors which is extra heat to the already hot cells. Some hotspots will soon melt or even burn the backside of the moduls. When your old modules have been sucessfully destroyed by the mirors you can replace them with newer ones that have more efficiency, using Sunpower cells or Sanyo/Panasonic HIT cells.

You should then remove the mirrors.

Otherwise live with what you have. There is no real practical solution to your question besides mounting better modules after removing the old ones.
 
thanks for the sarcasm cephalotus.....there was actually good points hidden behind it :D
i know im better leaving them as is (as they still work great) and getting more...but what size and where to put them :S

just had a look for a 270w panel.....cheapest i could find was this
https://www.ebay.co.uk/itm/Photovoltaic-Solar-Panel-270W-24V-Polycrystalline-System-House-Cabin-Camper/132483684993?epid=13013788601&hash=item1ed8a49a81:g:83MAAOSwCpRbF8ld at about 155 quid including postage.......preety good wattage/money£ ratio

but......mounting it properly/safely to my 2nd storey roof.....wouldn't be. (id have to but a frame n. hire contractors most likely)
in the UK they all seem to not want to mount your hardware though.....you have to buy their stuff (big scam, so many robbing cunts in the industry)

i could put it in my garden or on a wall by myself or even one of my lower 1st storey rooves.......but my gardens pretty much completely overshadowed except for a few hours midday. mounting to a wall would be "ok" for me to do by myself (on the cheap) there isnt much room there either and what there is, is again is overshadowed for a lot of the day.

im looking into it but my father seems reluctant for me to ruin his lawn....or put holes that "could" leak in his 1st storey roofs.

i orderd 2x 20w flexibles as a tester for one windows before i invested int he rest...(they finally came today,took sooo long)
mounted in about 5 minutes.... and even behind the skylight windows the seem to be making good on their power claims for a large portion of the days light as well.

currently their only charging a 12v battery through a crappy maplins pwm solar charger. i might invest in the rest (another 80ws) and maybe a cheapy more efficient ppmt charger....(someone suggest one please)

maybe if a post up an overhead pic of my house you guys can get a better idea of what im working with here. and advise me better on where to go with it:p

thanks again
jim
 


heres my houses overhead view.....according to google maps up on the picture should be north. i believe it :p

looks like i could get someone to fit about 8-10 200watt panels under my skylights similar to what i have already. install would be pricey though :(
£155 x 8to10 is £1240 to £1550 in panels alone.....
 
haha.....already way ahead of you on the efficient appliances, etc.

every bulb in the house is a 5w led or lower now saving about 15 watts per fluorescent bulb i replaced, about 20 of them in total soo... a potential 300 watts saved there.

the fridgefreezer rated A onth euk rating thing, like our tvs etc plus they are hardly on and if they're not they are switched off at the wall.

if only i cold get my parents to stop drinking tea/coffee id save a fair bit from not using the kettle all the time.
 
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