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Comment by jdiez17 | Hacker News Reader

From a quick search, most solar panels I can find are 15-20% efficient, so (from a quick look) this seems like a noticeable improvement, no?

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It's not a noticeable improvement in efficiency for solar heating. Solar heating was already ~70% efficient at converting incident sunlight to heat for water heating [0]. So it's important to note that this efficiency includes losses for circulating the water within the storage system.

[0] http://en.wikipedia.org/wiki/Solar_water_heating#Economics.2...

The concentrated solar power facilities have more efficiency (but you can't put one of them on your rooftop). From http://en.wikipedia.org/wiki/Concentrated_solar_power

> As of 2008, the world record for solar to electric efficiency was set at 31.25% by SES dishes at the National Solar Thermal Test Facility (NSTTF).

The 90% * 60% number is probably very optimistic.

The Wikipedia article is also interesting, because it discuss that when the temperature is too high the heat receiver is an important heat emitter. I didn't thought about that.

It's a noticeable improvement once you reach that scale of operations. But that's not all that easy. Solar panels are nicely decentralized.

On the other hand, the output of concentrated solar power can be much more constant.

15%-20% is for photovoltaic solar cells (http://en.wikipedia.org/wiki/Photovoltaics): where sunlight is converted directly into an electical current. The article here talks about converting solar irradiation into pure heat.

Yeah, but gus_massa calculated the upper bound of the sunlight->electric current conversion using the material we were talking about, which seems like an improvement to me. However I don't know what the ballpark efficiency of solar heat plants is, so it could turn out to be not that big of a deal if current modern plants achieve similar levels of efficiency.

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