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suggestion for project at wheaton labs

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Hi All,
I would like to submit an idea for development at Wheaton Labs. Essentially the idea is to build a small array (3x3) of small mirrors (something like 2'x3') that can be freely adjusted by a microcontroller (an Arduino would probably do the trick, but a Pi or BeagleBone could provide more power if needed).

It could be developed in phases. The first being to simply reflect the light from the sun into an approximate location. This could allow you to, for example, hang a PV panel on the side of a building where it is relatively protected from the elements, and allow the cheaper mirrors to reflect the sunlight on to it. In addition you could reflect the light onto a thermal mass (like a cob block with a coiled tube running through it) where the heat could be retained (with the block possibly being insulated with something like slip straw).

The second phase could involve attaching a set of motors to each individual mirror. With the use of some trig functions (which are included in the core arduino libraries) it should be possible to create a focal point that can be moved in three dimensions. This would allow you to increase the intensity of the light such that 54 sqft (3x2ftx3x3ft) of light might be focused onto something like a 2'x4' PV panel, at 16sqft. If this worked you could push the PV output to near it's theoretical limit. In this way you could buy fewer expensive panels and get greater output from them.

In addition to the application for PVs, it could be used to store heat energy in a kind of thermal battery, it could be focused on a rock that's painted black to melt snow, it could heat up a kiln, or any number of other tasks. And, it could be automated such that the thermal mass is always heated in the last hour of the day, or you could set it up on interrupts such that fully charged batteries cause the mirrors to reallocate the heat energy somewhere else.

Well, it seems like I've rattled on enough. I hope it's of interest, and that it can be worked into something useful.

Thank you very much for your time and consideration.

master steward
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Location: missoula, montana (zone 4)
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We bought this heliostat for $300 and it is worth, maybe, $10 as "garden art" and should not be sold as a "heliostat"

It does move throughout the day to point sun to a variety of places. About 2% of the time the sun actually goes into the north facing glass door that is supposed to collect sun.

Steve Funk
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That is a pretty sculpture, and with the one part missing it seems to capture the disenfranchised fragmentation of society in a post-modern...err...sorry.

Anywho, I was thinking more along the lines of a nano-scale version of something like the attached image (sorry, I'm still learning how to use the forms and embedding images currently exceeds my abilities).

Instead of focusing the light from many mirrors onto a single point to melt sodium (or whatever other design they use), a small number of mirrors might be able to deliver a less impressive, but still useful amount of energy. And with the ability to move the focal point it could be distributed to any line of sight location you'd like.

[Thumbnail for solar-furnace.jpg]
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