Can reflected light help generate electricity with a solar panel?

[sach963]

Can we use a mirror to reflect sun's light on a solar panel and generate electricity?

 

[RUber]

Yes.

 

[sach963]

Thanks!

 

[CWatters]

This only works up to a limit. Solar panels get less efficient if they are hot.

Scattered light can also be used. Solar panels still work on cloudy days, just not as well.

 

[inveni0]

Yes, but you'd likely be better off replacing that mirror with another panel. =)

 

[Drakkith]

Yes, but you'd likely be better off replacing that mirror with another panel. =)

Well, mirrors are much cheaper...

 

[sophiecentaur]

Well, mirrors are much cheaper...

However, there is a maximum current per unit area that a cell can give you so mirrors will not help with max available power for a given panel, designed for full sunlight. A suitable reflector system can have the effect of tracking the sun as it changes position, though.

 

[brianhurren]

I have a 120 watt solar panel on my van. i installed it to experoment with. I am quite impressed with it. I have found that the amount of power u get from it even on a cloudy day is quite significant. on an absolutely filthy day teaming with heavy rain. I still get about 10% of rated power. on a full sunny day I found there was really no need to have it track the sun as the sensitivity of it is quite wide. full power over at least 120 degrease. in the middle of summer, with the sun rising at about 7 oclock dst. batteries would be fully charged by about 10am that's after running an led light and the car stereo on all night.

 

[sach963]

does a solar panel work on heat or light?How does it work?

 

[brianhurren]

it works on light, heat actually degrades its performance. they are most sensitive to the near infrared part of the spectrum. because of its sensitivity to near infared (that is the part of the spectrum just below visible hence 'near infared' as opposed to heat which is far infrared. they can still give resonable performance even on a cloudy day. your typical solar panel loses about 1% of its performance every year due to oxidation and heat.

 

[OmCheeto]

However, there is a maximum current per unit area that a cell can give you so mirrors will not help with max available power for a given panel, designed for full sunlight. A suitable reflector system can have the effect of tracking the sun as it changes position, though.

I totally agree.

I was doing some serious number crunching on solar the other day, saw this thread yesterday, and added them together.
I'm around latitude 45, and I decided that a reflection system would be most useful in the winter.

Output is in watt-hours per day for a 1000 watt system:

              summer    fall  winter
w/o mirrors    11958    8759    4935
with mirrors   14173   11161    7779
improvement      19%     27%     58%

Of course, I would imagine that engineering a mirroring system might be a problem, as I'm sure we'd have seen one if it weren't.
Over-exposing the panels with a poorly designed mirroring system would simply wear them out sooner, with no output benefit.

The other thread: Question about solar energy: angle of incidence

 

[sophiecentaur]

Code (Text): summer fall winter
w/o mirrors 11958 8759 4935
with mirrors 14173 11161 7779
improvement 19% 27% 58%

That's useful data. So, if you just have twice as many panels, you can get what you need all year round. Panels are getting cheaper and cheaper whilst clever motors, mirrors and installation costs will be more and more. Brute force and ignorance seems to win.

 

[OmCheeto]

That's useful data. So, if you just have twice as many panels, you can get what you need all year round. Panels are getting cheaper and cheaper whilst clever motors, mirrors and installation costs will be more and more. Brute force and ignorance seems to win.

Ignorance? Ignorance is conquered with experiment!

I was going to do some experiments with alternate methods of solar reflection collection: Red neck NASA by-product, white sheet, remnant from kitchen flooring project, 6000 AOL cd disks, etc, etc...
But after a foggy morning, a very sunny midmorning, it's clouded up again.
Maybe tomorrow. The forecast looks brighter. (temps are in "Imperial units", btw.)

 

[sophiecentaur]

Ignorance? Ignorance is conquered with experiment!

Not ignorance on your part, dear chap - just ignorance in general.
The developers of PV cells are pretty smart and their design is based on a moving light source so the best deal will be what they recommend for your latitude. If you can't handle excess power then it may be best to point one set of panels slight west and one set slightly east if you want to get the best out of a large array. Perhaps and Excel spreadsheet could come in handy here. The really optimal solution could involve some clever planning.
"Imperial" haha. That would refer to the American Empire these days, no doubt. Europe is largely our master these days and Napoleon started all that SI rubbish. Blame him.

 

[brianhurren]

Not ignorance on your part, dear chap - just ignorance in general.
The developers of PV cells are pretty smart and their design is based on a moving light source so the best deal will be what they recommend for your latitude. If you can't handle excess power then it may be best to point one set of panels slight west and one set slightly east if you want to get the best out of a large array. Perhaps and Excel spreadsheet could come in handy here. The really optimal solution could involve some clever planning.
"Imperial" haha. That would refer to the American Empire these days, no doubt. Europe is largely our master these days and Napoleon started all that SI rubbish. Blame him.

after my own experementation with solar panels and a campervan..that is good advise.

 

[brianhurren]

I totally agree.

I was doing some serious number crunching on solar the other day, saw this thread yesterday, and added them together.
I'm around latitude 45, and I decided that a reflection system would be most useful in the winter.

Output is in watt-hours per day for a 1000 watt system:

              summer    fall  winter
w/o mirrors    11958    8759    4935
with mirrors   14173   11161    7779
improvement      19%     27%     58%

Of course, I would imagine that engineering a mirroring system might be a problem, as I'm sure we'd have seen one if it weren't.
Over-exposing the panels with a poorly designed mirroring system would simply wear them out sooner, with no output benefit.

The other thread: Question about solar energy: angle of incidence

your last statement is a very good point. if you over work the panel it would produce excess heat and deteriorate the junctions faster and damage the panels.