shadowmaker
Solar Addict
I'd say go for it. You probably have no major issues with snow like I do...
What is the best choice for reflective surface paint under Bi-facial panel(s)?
- Thread starter Tony S
- Start date
It's tempting. Yeah in Dallas 0.1" of snow per year is the official figure
Bluedog225
Texas
- Joined
- Nov 18, 2019
- Messages
- 2,917
Seems high?
The whitest paint is here – and it’s the coolest. Literally.
In an effort to curb global warming, Purdue University engineers have created the whitest paint yet. Coating buildings with this paint may one day cool them off enough to reduce the need for air conditioning, the researchers say.
www.purdue.edu
The problem with this, is winter ?The whitest paint is here – and it’s the coolest. Literally.
In an effort to curb global warming, Purdue University engineers have created the whitest paint yet. Coating buildings with this paint may one day cool them off enough to reduce the need for air conditioning, the researchers say.
Warpspeed
Solar Wizard
If I were doing something like this myself, I would not use paint.
I would buy a very thin sheet of mirror backed stainless steel.
It will last forever, very easy to keep clean and looking good, and easily removable.
I would buy a very thin sheet of mirror backed stainless steel.
It will last forever, very easy to keep clean and looking good, and easily removable.
Mirror backed stainless steel? What's the reflecting of that? I bet it's not better than white paint
Warpspeed
Solar Wizard
Sure is.
Mirror stainless can be polished to act as a real mirror, very efficient at reflecting all light.
You cannot see your own reflection in white paint !
Unpolished it looks like a stainless steel kitchen sink (or urinal) even unpolished it still reflects much better than any paint.
Truckers love this stuff, its almost like chrome, but much more durable and easier to maintain.
Look at the reflections in the fuel tanks, rear mudguards, and front bumper of this truck:
Attachments
Polished stainless steel has a lower solar reflectivity index score then bright white.
Also, read the article posted above
OffGridForGood
Catch, make or grow everything you can.
Not a problem, in winter all the roofs are white, no matter what colour they are in summer
Warpspeed
Solar Wizard
The article says most white paint only reflects about 80% to 90% of solar heat.
Their "super paint" hits 98% which is pretty good for paint.
A metal reflector will easily beat white paint for reflectivity. For optical wavelengths in the visible spectrum, natural silver is the best, which is why mirrors are "silvered".
At infrared frequencies gold is better than than silver. You may have noticed space vehicles often use a lot of (real) gold foil. Not white paint !
Not in Texas unfortunatelyNot a problem, in winter all the roofs are white, no matter what colour they are in summer
You are quite wrong. What is the ACTUAL SRI of polished stainless steel or regular stainless steel?
OffGridForGood
Catch, make or grow everything you can.
Except in Feb 2021...?
Ok . For 4 days every 10 years . LolExcept in Feb 2021...?
OffGridForGood
Catch, make or grow everything you can.
I expect that only the part of the spectrum the solar panels can use will matter - for the PV collection part. The heat reflection part is a separate matter.
Warpspeed
Solar Wizard
Can you find a link to a source that compares white paint to pure silver as an optical reflector ?
The guys building mirror reflectors for astronomical telescopes sure do not use white paint.
The guys building mirror reflectors for astronomical telescopes sure do not use white paint.
OffGridForGood
Catch, make or grow everything you can.
Except in Amarillo... I've been told LOL!
Warpspeed
Solar Wizard
You could be right about the required spectrum, but it would make an interesting test to compare a large mirror to a similar sized white painted board.
Place a small solar panel so its completely shaded, then reflect some sunlight onto it via reflection only.
I have never tried this, but I would be very surprised if paint wins.
Its mid winter down here in Australia, so not much chance here of any good sun.
I would be even more surprised if a white painted surface survived as well as stainless steel over a few years of outdoor exposure.
Yes. But I asked first. What is the SRI of polished stainless steel?
Why wouldn't it?
Surfaces get whiter through exposure to the sun so a white surface would just get whiter over time.
Except that it would happen very slowly since bright white absorbs very little of the damaging sun rays, compared to other colors
Similar threads
