
The Godzilla of Solar Ovens - mcspecter
http://spectrum.ieee.org/geek-life/history/the-godzilla-of-solar-ovens#.V3QnRCuHeF8.hackernews
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esquevin
As the article suggests, the Mt Louis Solar oven was a prototype that lead to
the real godzilla, the Odeillo Solar Furnace:

[https://en.wikipedia.org/wiki/Odeillo_solar_furnace](https://en.wikipedia.org/wiki/Odeillo_solar_furnace)

This thing is massive and a beauty to look at. I remember going through the
tour in the 90s, there were very thick steel plates on display that where
melted like butter in the center it was really impressive.
[https://books.google.fr/books?id=VQEAAAAAMBAJ&pg=PA88&lpg=PA...](https://books.google.fr/books?id=VQEAAAAAMBAJ&pg=PA88&lpg=PA88&dq=odeillo+steel+plate&source=bl&ots=odQm2aDBiv&sig=hdNFLlmhAyVFsw5jelA1pdtaYkI&hl=en&sa=X&ved=0ahUKEwiN5Ymbuc_NAhXMWxoKHbY5AcUQ6AEIKjAD#v=onepage&q=odeillo%20steel%20plate&f=false)

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jacquesm
The Mt Louis Solar oven has been used for quite a few interesting projects,
one of the most interesting that I recall was the disposal of certain
extremely toxic chemicals at very high temperatures.

I built a 10' parabolic concentrator out of an old K-band satellite dish by
laminating it with mylar and that - even though quite small - was the scariest
thing I ever built.

It's only a few square meters but in full sun and with the focal point about
2-2.5 square centimeters you had to be extremely careful.

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JamesBaxter
I'd be interested in the health and safety of working around these systems.

It feels like the sort of thing it would be very easy to forget the danger of
as there's minimal moving parts and no scary sounds.

Surprised a henchman hasn't been thrown into the danger area in a James Bond
film yet.

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digi_owl
Well there have been issues with flash fried birds at a recently built solar
plant. And i think they also have a incident where the mirrors got misaligned
and set the collection tower on fire.

That said i think you would feel the heat radiating from the thing, as no
mirror is perfectly reflective.

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alejohausner
On sunny days, London's 'walkie talkie' building makes the sidewalk nice and
toasty (and melts plastic bits on your car) with its south-facing concave
glass wall:
[http://www.bbc.com/news/magazine-23944679](http://www.bbc.com/news/magazine-23944679)

Not quite a solar furnace, though.

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dmoy
There's a hotel in Vegas with a slight.... design flaw, causing similar
problems:

[http://www.nbcnews.com/id/39403349/ns/travel-news/t/death-
ra...](http://www.nbcnews.com/id/39403349/ns/travel-news/t/death-ray-vegas-
hotel-pool-heats-guests/)

Actually hang on, is it the same architect??

[https://en.m.wikipedia.org/wiki/Rafael_Viñoly](https://en.m.wikipedia.org/wiki/Rafael_Viñoly)

Maybe he's actually out to burn things on purpose... /s

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artofcode
Some people just want to watch the world burn

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ChuckMcM
This and the Odeillo plants are pretty amazing. It is remarkably easy these
days to build something which can create some really amazing temperatures. I
used a Fresnel lens from a 50" rear projection TV to build a concentrator for
the kids as part of a science project. We have also used more commercial solar
ovens[1] to cook bread and other parts of dinner in the backyard or at camp.

That said, I've always wondered if you could build an industrial processor
based on this technology. Can you bake iron out of hematite? Aluminum out of
bauxite? The interest stems from research on how one might actually go about
mining asteroids effectively. Using an inflatable mylar coated mirror could
you effectively distill metallic elements out of a rocky asteroid?

[1] [https://www.sunoven.com/](https://www.sunoven.com/)

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Retric
Using this on earth is hard because any clouds prevents this from get into
extreme temperate ranges. So, you have low utilization in the 10-30% range.

This also gets vastly harder the further you get from the Sun and the asteroid
belt is not all that close. A solar concentrator + solar panel + more
traditional methods may work better especially out in the ort cloud.

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ChuckMcM
Possibly, but you can make a kilometer diameter mylar mirror which folds up
into a pretty small pouch. A small puff of gas to inflate the 'struts' and
poof you've got more sun to work with. The asteroid belt is nominally 2.5AU
from the Sun and using the inverse square law would suggest 1/6th the amount
of solar insolation. So the Odeillo oven has 2600 sq meters of mirror and
generates temperatures of 3000 degrees. Our 1km dish would have 785,400 sq
meters so about 302 times the surface area, with 1/6th the insolation we
should get about 50x the energy out of it if my math is correct.

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Retric
Aiming a 1km dish is not going to be easy not to mention station keeping.
Also, while it's clearly producing a lot of heat and may even vaporize iron
that's not the goal. Further without Gravity many approaches for refining
materials don't work as heating a chunk may just eject it into space.

Alternatively if you look at it as a large and relatively cheap tool it may be
useful as a relatively small part of the process.

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ZenoArrow
I like this. Imagine if you took something like this to the desert, you could
have the means to convert sand into silicon without needing to use a locally-
sourced fuel to generate the required heat (For what it's worth, I realise the
sand that goes into silicon wafer production usually has to be purer than
commonly-found sand, but I still think this production method may prove
useful, perhaps for the silicon that goes into solar panels).

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silicon123
you would still need carbon for reducing the silicon dioxide into silicon

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Frenchgeek
Burn magnesium in carbon dioxyde captured from the air then electrolyse the
magnesium oxyde to get useable magnesium back?

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adrianN
Plant some trees, make charcoal?

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Frenchgeek
A bit difficult to do if we're in a desert, I think...

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peatmoss
I used to live in a place with a strong ecological ethos for recycling, but no
economic use of recycled glass. I always wondered if one could pulverize glass
and extrude extremely durable housing structures using a solar-fired glass
melting 3d printer.

Throw bottles in; slowly extrude house on sunny days...

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jpindar
That's a really interesting idea. 3d printing glass is a thing (and it looks
awesome), but I'm not sure how to get the solar heat to the moving printhead
without overheating the rest of the printer.

[http://www.thisiscolossal.com/2015/08/3d-printed-
glass/](http://www.thisiscolossal.com/2015/08/3d-printed-glass/)

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hantusk
See also this godzilla of solar plants :)
[http://www.fastcoexist.com/3057288/this-huge-new-solar-
farm-...](http://www.fastcoexist.com/3057288/this-huge-new-solar-farm-near-
las-vegas-provides-power-even-at-night)

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venomsnake
>By 2020, China plans to build 10 more—the equivalent of 100 solar farms the
size of Crescent Dunes.

The ability of china to scale never ceases to amaze me.

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semi-extrinsic
One of the upsides of not being a democracy is that NIMBY, environmentalism
and health&safety can be pushed much further down on your list of
concerns/priorities.

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imglorp
All true, but in this case there's millions of acres of cheap desert in the
US. I think there's other forces than those retarding solar progress.

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Spooky23
That doesn't mean that nobody cares. Republicans in the West hate solar
because of their historical ties to coal and petroleum.

Environmentalists dislike these things because they are essentially a death
ray for birds.

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specialist
Ya. Armchair treehuggers, like their brethren on the right, can be exhausting.
Every year, feral cats kill billions, wind turbines 500k, office buildings
another 100k...

Focusing on least harm is far more constructive then selective outrage.

(I volunteered at Audubon for a decade, trying to conserve habitat for fish,
birds, trees, etc.)

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walrus01
If you want to do this on the cheap, see if you can find an old C-band mesh
satellite dish. They can be found for free in rural areas of the US and Canada
where people have them rotting in their yard. Like so:

[http://www.vk3nro.com/122East2014/CBandDish.png](http://www.vk3nro.com/122East2014/CBandDish.png)

Cover in aluminum foil or mylar or whatever is cheap and highly reflective.
Cook food at the location of the feed focus.

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camperman
I have a 2.5m solar oven and it's brilliant. It can boil a litre of water in a
minute or so on a sunny day.

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mrmondo
If you're blocking ads for privacy / security reasons this site doesn't load
at all: [http://i.imgur.com/lWxMl7B.jpg](http://i.imgur.com/lWxMl7B.jpg) while
you see this on some sites with paywalls etc... I've never seen a site _this_
broken.

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kriro
Works fine with uBlock (OS X latest, Firefox latest)

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mrmondo
OS X Latest, Chrome Canary / Firefox Dev Edition

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spbookie
23 September 2013??

