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Comment by dangayle | Hacker News Reader

I'm no scientist, but would there be a way to combine this with solar panels to also produce electricity? It seems the goals are counter to one another, but it would really be amazing to accomplish both with one panel.

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Since the device emits energy within a narrow range, perhaps it be possible to build a top-most layer that acts like an antenna for that range? Then you'd have a pump that absorbs heat from the environment, squeezes in into a narrow band, and emits it into a wire.

Or, I suppose you could park a Stirling engine on it and generate power from the thermal gradient it must be producing.

At the very end of the methods section, they write: "Future designs and configurations may find ways of using this reflected sunlight, enabling shorter payback periods and lower levelized costs." I don't have any idea what they have in mind.

This same group is also trying to solve a related problem, which is how to keep solar panels cool, since they are less efficient when they heat up. They have designed coatings that are transparent to sunlight and dump heat to space ( http://www.opticsinfobase.org/optica/fulltext.cfm?uri=optica... )

If it is used on top of a building certainly the defrosting features of masts and other fittings look mootable; skylights have shades; you can use the stuff as the concentrating optic of your choice, so to choose smaller water or thermovoltaic systems, heat and circulate the pool (hot tub) on the roof, etc. Taken to architectural limits, thermal cycling wear on all roofing is lessened. Silage and water loop uses exist as LEED elements, and the swept radiant flux can even agitate self-cleaning glass.

I think you could combine the two in parallel. A problem with solar panels is that their efficiency drops as they heat up. It might be cost effective to use these panels as heat sinks for a solar panel for passive cooling.

That said, the material is specified to have a cooling capacity of ~40Wm^-2. You normally assume something like ~800-1000Wm^-2 for incident solar radiation, so I'm not sure how economical using something like this with a solar array would be.

Really cool though.

Put the solar panel on top of it at an angle. The roof will keep radiating heat, and some of it will hit the bottom of solar panel, but that's probably ok. Maybe can put reflective material on the bottom of the solar panel so it bounces around until it finally escapes.

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