Regular parabolic mirrors are great for concentrating sunlight for solar heating, however they are bulky and can be difficult to repair. That’s where Dominic Wanjihias’ flat parabolic mirror comes into play. He replaced the traditional curved mirror with a series of thin strips of mirror, making what appears to be a Fresnel reflector. It’s a pretty simple concept, but has a bunch of practical advantages:
- It is very cheap,
- It can be quickly dismantled or moved,
- It is easily transportable as it can be carried flat or in a tube,
- It is easily repaired if broken as the individual mirror pieces can be replaced (rather than having to fix or replace an entire parabolic mirror).
It’s not mentioned in the article, but I assume that the individual pieces have to be bent into a curve shape to be able to focus light to a point. Anyone know for sure? [via afrigadget]
14 thoughts on “Making a flat parabolic mirror”
This is more like the parabolic troughs you see in the Mojave desert, so it still concentrates solar energy, but on a line instead of a point.
I bet it’s great for toasting baguettes!
Ha, awesome! Now I like the idea even more!
No need to make the strips curved. When they lock onto the sun, they’ll reflect around a 1″ band of light. As long as all the mirrors converge, it should work.
but yeah, it’s a pretty long 1″ band of light…
That’s exactly what you want, if you’re trying to heat water (or something else) flowing through a long pipe.
Ah! Good point!
If you want cheap, simply take one of the satellite dishes from any house — the one that have been made obsolete, of course, by the installation of new ones. Ask the Dish Network guy for them, he’ll be glad to get rid of them. Then use a viscous silver paint — viola!
Flat mirrors work fine and they will focus on a line so pipes work as stated above. There is a company that makes large versions. http://www.ausra.com/technology/
By rotating each individual mirror they stay focused on the collector.
I wonder if an array of simple round mirrors with motors controlled by an arduino mega would be of use?.
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