• Nick Orf PhD ’09 demonstrates a prototype Thermeleon roof tile, using a heat gun to warm part of it. The heated area turns from black to white.


    Patrick Gillooly

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    Patrick Gillooly

    Full Screen

Energy savings in black and white


MIT students develop concept for color-changing roof tiles that absorb heat in winter, reflect it in summer.


It's no small matter. In fact, Chu says that turning all the world's roofs white would eliminate as much greenhouse gas emissions in 20 years as the whole world produces in a year. But some critics point out that in northern cities, the gain in summer could be outweighed by the loss in winter. The ideal situation, then, would be to get the advantage of white roofs when it's hot and black roofs when it's cold.


The team's lab measurements show that in their white state, the tiles reflect about 80 percent of the sunlight falling on them, while when black they reflect only about 30 percent. That means in their white state, they could save as much as 20 percent of present cooling costs, according to recent studies. Savings from the black state in winter have yet to be quantified.










Topics: Making and Designing Materials Engineering Contest (MADMEC), Materials science, Innovation and Entrepreneurship (I&E), Energy, Environment, Students, Contests and academic competitions


Hey belg4mit,

If your roof is white in winter, how does it absorb heat ? It reflects heat!

I don't think snowfall would have enough impact on the roof color to significantly alter efficiency.

First, in my area (and I assume in most temperate zones), cool temperatures do not necessarily (in fact, rarely) mean snow will be present either due to lack of precipitation or temperatures just above freezing.

Second, assuming snow is present, it snow would not melt any faster on a control black roof. Therefore, as long as there is one cool day without snow, there is an efficiency increase.

I think Thermeleon certainly has a place in the future of efficient housing as long as it can be kept affordable enough to convince consumers to make the switch.

Only someone who doesn't know the difference between "your" and "you're" would ask "what's the point?"

I know it is still very preliminary, but I am curious to know what impact these tiles can resist. In South Texas, we would welcome this technology as long as they wouldn't crack at the first hail storm. Brilliant concept!

Thats an amazing idea yet its so simple, its also funny that they call themselvs thermeleon after a chamelon. Guess innovation starts in the smallest cracks and works its way to a earthquake.

I saw the chameleon word connect right away, before I got far into this fascinating research. It seemed so obvious, and, of course, apt.

It's an ELE c TRICK idea, one that truly gives homage to chamELEons.

good idea

I picked this up on LinkIn. I'm estatic about the thermeleon's work developing color changing tiles. I'm a distributor for building envelope materials including concrete tiled roof panels with "color" solar panels. I would indeed love to have this product to distribute when it is ready to be manufactured and marketed. Let me know if you need sources for manufacturing.

This is a great idea but another company has already thought of it. You can check them out at movingcolor.net.

Vow! This is amassing! If it's transparent when cold maybe it could also be applied to windows. For instance half of a window could be covered with this new material.

I like your idea of maybe having a pigment to paint on to an exsisting black roof. If you want to test it on a roof , you may use ours. We live in san antonio, texas and it gets hot here. Please reply. maybe we can work together on this. Very exciting. Thanks ed

If a house is properly insulated (and if it's not, doing so would be cheaper than waiting to install these), snow will accumulate on the roof (since heat will be leaking up to melt it), giving those in the north a white roof for much of the winter anyhow.

Yes, that's exactly the point: that the advantage of a white roof that's supposed to become black in the winter for some extra heat gain would be at least partially negated by unmelted white snow i.e; a de facto white roof.

IMS has a coating which changes color with temperature and is used on roof, siding, roads etc. see www.innovativemfg.net

Someone else said what I was going to....if your roof is so poorly insulated that it lets heat and cold in, it's time for a new roof, and proper insulation. As you drive around in winter, take notice of roofs that have a few inches of snow on them, compared to ones where the snow has melted. The ones that still have snow are insulated, the ones where the snow has melted are letting their furnace do the melting by letting that air escape with lack of insulation. By this rule, even if the roof attracts heat, with proper insulation, it would do no good.

Dr.A.Jagadeesh Nellore(AP),India

What has happened with this research over the past six years? Would be interested in hearing an update.

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