
New solar dish from MIT concentrates sunlight intensely enough to melt steel - sah
http://www.dailytech.com/MIT+Students+Develop+Revolutionary+Solar+Dish+That+is+Hot+Enough+to+Melt+Steel/article12153.htm
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dcurtis
I walked past this the other day when they were building it out in front of
MIT. What was amazing to me was not that it can melt steel, but that the
mirrors they used were built to such perfect concavity with insanely smooth
surfaces. The article suggests a possible application of the technology is
bringing heat and solar electricity to poorer countries, but I have a hard
time believing those perfect mirrors are really that inexpensive.

To compare this thing to anything Archimedes could have made is laughable.

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hugh
Is it really that impressive compared to the mirror in any of the world's
largest telescopes? I mean, good work being built by students at low cost and
all, but any serious observatory will have a mirror which is larger and a lot
smoother.

On the other hand, I just got back from my first trip to Chicago where I was
insanely impressed by the giant mirrored jellybean in Millennium Park, so I
don't deny the impressiveness of big shiny objects.

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wallflower
"When Marcellus withdrew them [his ships] a bow-shot, the old man [Archimedes]
constructed a kind of hexagonal mirror, and at an interval proportionate to
the size of the mirror he set similar small mirrors with four edges, moved by
links and by a form of hinge, and made it the center of the sun's beams – its
noon-tide beam, whether in summer or in mid-winter. Afterwards, when the beams
were reflected in the mirror, a fearful kindling of fire was raised in the
ships, and at the distance of a bow-shot he turned them into ashes. in this
way did the old man prevail over Marcellus with his weapons."

"Archimedes and his Burning Mirrors, Reality or Fantasy?"
<http://www.mlahanas.de/Greeks/Mirrors.htm>

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aswanson
Wonder what its efficiency is compared to a Fresnel lens:

<http://www.youtube.com/watch?v=DGtA8E5iw3k>

[http://images.google.com/imgres?imgurl=http://www.terrypeppe...](http://images.google.com/imgres?imgurl=http://www.terrypepper.com/Lights/closeups/illumination/fresnel/fresnel-
orders.gif&imgrefurl=http://www.terrypepper.com/Lights/closeups/illumination/fresnel/fresnel.htm&h=435&w=281&sz=8&hl=en&start=16&tbnid=l34jDm9V39EF9M:&tbnh=126&tbnw=81&prev=/images%3Fq%3Dfresnel%2Blens%26gbv%3D2%26hl%3Den%26sa%3DG)

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jsmcgd
What is patentable about this? I don't understand what is novel about it.

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Xichekolas
I was wondering the same thing. I wish the article would have focused on what
was novel about this design compared to other solar-thermal dishes like
Sterling Energy Systems, (<http://www.stirlingenergy.com/>) which is putting
up 850MW worth of dishes in the desert.

Also I have to wonder if they could benefit by using a different working fluid
than water. A lot of solar thermal projects use low melting point salts as the
working fluid, since they hold heat for a long time. You can heat the salt all
day, then hold vast amounts of superheated salt in holding tanks, and heat
exchange it with water to drive steam turbines. This allows you to produce
power well into the night.

