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'Whitest ever' paint reflects 98% of sunlight

bbc.com

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Re: 'Whitest ever' paint reflects 98% of sunlight

#171

Post by kube-system »

clairity wrote: post #129
kube-system wrote: post #66

Earlier quoted context omitted.

There are a lot of practicality/implementation concerns to paint other than what color it is. Just as many if not more than there are for battery technologies. Does the paint stick to the surface you want to paint, how is it applied, what is the coverage, is it durable, does it repel contaminants, can it withstand the environmental conditions, is it chemically compatible with the surface, it is chemically a concern f…

one thing i’ve learned from doing little home improvement projects over the past few years is that paint is a 2-part product, primer and topcoat, and neither should be skipped if you want good results. generally speaking, primer sticks and seals while topcoat colors and protects. this isn’t made obvious in any way to the novice, and big box store workers seem as ignorant about it as anyone.

And that's just for home improvement store paint. More sophisticated painting processes, like for automobiles, can be 5+ different types of coatings.

i.e. electroplate > primer > base > mid pearl > clear

Re: 'Whitest ever' paint reflects 98% of sunlight

#172

Post by abootstrapper »

lm28469 wrote: post #162
abootstrapper wrote: post #146

Earlier quoted context omitted.

I don’t agree with your cynicism. This is a very practical, potentially accessible, inexpensive solution to save literally tons of power. It’s an easy win. Let’s take it and move on to the next area we can make gains in the fight against climate change.

> practical, potentially accessible, inexpensive Painting 1% of the world in white paint is everything but that. It's a cool gadget that will be experimented in a few niche places and quickly and quietly abandoned when real life kicks in. How often will it need to be cleaned ? repainted ? How much will it cost to paint your building's roof, is you building roof even paintable in the first place ? What is the paint ma…

Presumably most buildings are painted. My house for example. If painting it white saves %10 of my energy costs in the summer, how is that anything but a net positive? BTW, I’m in the market for a new roof. I’m going white painted metal.

Are double pane windows, solar panels, and insulation also gadgetry hype?

Re: 'Whitest ever' paint reflects 98% of sunlight

#173

Post by aksss »

FredPret wrote: post #97
quickthrowman wrote: post #64

Earlier quoted context omitted.

You need machine tools capable of tight tolerances and quality metals/alloys to make useable (for work) steam engines. The Egyptians, Greeks, Romans, Abbasid, Persians, Europeans, etc all lacked these, thus no usable steam engines in antiquity/Middle Ages. Usable engines followed consistent quality metal production and machine tools pretty closely, it’s not like older people were just stupid, they didn’t have the tec…

Good point regarding tooling, metal, and tolerances. But in this hypothetical timeline they would’ve hand-made the first leaky and inefficient engine if someone with some clout had the idea for a piston back then. These people didn’t blink at moving mountains to build burial crypts, so it’s conceivable that they might’ve experimented with steam if that notion struck, say, the pharaoh.

Smil’s book about Making the 20th Century has some good context for this type of discussion. Highly recommended if interested in how technical leaps happen.

Re: 'Whitest ever' paint reflects 98% of sunlight

#174

Post by d33lio »

I wonder if there's a marked disadvantage to using this on aircraft? I'm curious if some form of this tech has existed for decades for use on nuclear response TACAMO aircraft? Depending on the frequency response, it seems like this could be a horrible material to coat an aircraft with, due to IR reflectivity?

My uncle works at Tinker AFB in Oklahoma and always used to explain the different unique features of TACAMO [0] aircraft. Also, on a side note, he currently has his identical job he held in the air-force as a civilian and collects multiple pensions (albeit, he was always my "cool engineer uncle" who bought me my first soldering iron).

[0] - https://en.wikipedia.org/wiki/TACAMO

Re: 'Whitest ever' paint reflects 98% of sunlight

#175

Post by snug »

mrob wrote: post #19
jbverschoor wrote: post #10

Can someone explain the difference between this and a mirror? A mirror reflects also something like 98%, right?

A mirror reflects with specular reflection. When parallel rays of light hit a flat mirror they remain parallel after being reflected: https://en.wikipedia.org/wiki/Specular_reflection Paint reflects primarily with diffuse reflection. The rays of light are scattered in all directions: https://en.wikipedia.org/wiki/Diffuse_reflection

I was going to ask this same question, thinking it would be a dumb question, glad this got answered! Thank you

Re: 'Whitest ever' paint reflects 98% of sunlight

#176

Post by xjlin0 »

FredPret wrote: post #120

"We did a very rough calculation," said Prof Ruan. "And we estimate we would only need to paint 1% of the Earth's surface with this paint - perhaps an area where no people live that is covered in rocks - and that could help fight the climate change trend." LMAO me I love living in the future. This sentence could’ve been lifted from the Hitchiker’s Guide to the Galaxy.

Or, please cover Earth's surface with plant, which may already cover more than 1% of the surface, and can convert sun energy to something we can use.

Re: 'Whitest ever' paint reflects 98% of sunlight

#177

Post by dheera »

neurostimulant wrote: post #152
dheera wrote: post #130

Earlier quoted context omitted.

I tried it. It's not that black at all. My regular black T-shirt was blacker than a piece of cardboard I painted with Black 3.0. Super disappointing, to say the least.

Maybe it was applied wrong? The website mentioned that porous materials must be sealed first before spraying with black 3.0.

I did prepare it with Black 2.0 first.

Re: 'Whitest ever' paint reflects 98% of sunlight

#178

Post by cwkoss »

toss1 wrote: post #169
btbuildem wrote: post #163

White roofs are great -- just like snow, the high albedo means a lot of the heat energy is reflected not absorbed. But.. the ultra-white paint, on a roof? Perhaps it will be ultra-white on the first few days. Rain, pollution, dust, smog, and a myriad of other particulates (esp. in an urban setting) will quickly render it off-white, and bring it on par with existing finishes.

It seems the existing finishes would also degrade along exactly the same curve. Starting at a higher point on the curve might leave this finish, in it's environmentally degraded state, still brighter than the other white finishes when new, and certainly brighter after both are exposed. Also, if this were that big a problem, it seems that solar panels would fail. It seems that rain often counteracts the pollution, dus…

Solar panels will drop in effectiveness as they get dusty and dirty. They need to be cleaned periodically.

Re: 'Whitest ever' paint reflects 98% of sunlight

#179

Post by qwertywert_ »

lm28469 wrote: post #138

You can tell we collectively lost it when white paint is presented as a solution for climate change... You know what's big, white and help with climate change ? The ice caps we're destroying. We won't replace them with paint

Just because something sounds silly doesn't mean you should just dismiss it right away, cynicism doesn't really help.

Re: 'Whitest ever' paint reflects 98% of sunlight

#180

Post by m463 »

tediousdemise wrote: post #79

I bet this would look fantastic mixed with some vantablack, for the greyest grey achievable.

I think what might be interesting is like two-sided louvers over your roof. black on one side, white on the other.

Flip from one side to the other to help maintain temperature by absorbing or reflecting sunlight.

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