
Tracking solar collector without electronics (2011) [video] - dmos62
https://www.youtube.com/watch?v=WrMltEp-dcw
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kumarvvr
Electronics are incredibly cheap and an electronic version would be smaller,
lighter and more reliable.

I definitely appreciate the effort and am very interested in similar
approaches, but for commercial use, electronics based systems are very cost
effective, especially if engineered for a specific project and optimized.

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dmos62
This is meant for third-world countries where you need easily maintainable and
accessible components. Plus, using electronics implies an infrastructure that
we take for granted: it's more complicated in rural third-world.

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kumarvvr
You see that reflector, gears, evaporating liquid stuff in the solution, yeah
that will not last 3 months in a rural area. For a rural area, _this_ is a
complex setup.

In 1 week, you would either have bird shit all over the control mechanism
light reflector, probably have a bird build a nest in it, or perhaps have a
flying piece of plastic tangle in the mechanism.

Electronics does not imply an infrastructure we take for granted. Just look at
mobile phone usage in African countries. No one thought mobile phones are a
bad idea because they don't have the infrastructure to repair them.

A motor controller with a motor attached is cheap, can be made to work for
years, sealed off in a water proof and dust proof container, and still be
configured with bluetooth.

And, the infrastructure problem you talk about, that will only be solved with
consumers in the first place.

No one in Africa built a mobile repair business without the phones being their
first.

Sorry, your perspective is negative and counter productive.

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dmos62
Look, you could be right. I don't really know what the supply dynamics are
anywhere in the third world. The author does travel the third world for
humanitarian purposes, so I'm making guesses based on that. This project, that
was posted ~9 years ago, is the most complicated project he posted. His newer
projects are mostly simpler and he did create electric wind and hydro
turbines. So I'd guess electricity is a problem at least some places and
electronics are accessible enough to consider these projects.

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perilunar
That's very clever, but wouldn't a simpler way to track the sun without
electronics be to use a mechanical clock set to local solar time?

You'd have to rewind it and adjust the time slightly every few days, but then
the mechanism in the video doesn't appear to have any way to return at the end
of the day, so probably has to be reset daily anyway.

~~~
dmos62
That's a cool idea, though a mechanical clock could be hard to come by in
certain places. Most of the things this guy makes are meant to be very cheap
and accessible in the third world. I recommend his channel. A lot of fun low-
tech stuff like DIY water filters in Uganda, a vertical wind turbine, a "Kiwi"
DIY wind tunnel for that wind turbine (mounting it on a car and going for a
drive).

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carapace
You can make crude mechanical clockwork out of wood.

E.g.
[https://www.lisaboyer.com/Claytonsite/Claytonsite1.htm](https://www.lisaboyer.com/Claytonsite/Claytonsite1.htm)

These are obviously more elaborate than you'd need because they're artwork as
well as functional clocks. (Some are just kinetic sculptures.)

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PaulDavisThe1st
That's interesting. In the 70's Steve Baer (Zomeworks) was doing this sort of
thing using freon, which obviously became a chemical-non-grata. The zomeworks
trackers didn't use gearing, just weight transfer between two freon canisters
on either side of the solar receiver. It's nice that ethanol can be used in a
similar way.

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jacobush
Probably water can be used in the same way, if the collector was larger.

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iAm25626
Commercial application using wax cylinder:
[https://www.sulasindustries.com/media](https://www.sulasindustries.com/media)

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dmos62
Why wax? Is it unique in how it expands/contracts when heated/cooled?

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jacquesm
Wax has a very high expansion coefficient and is dirt cheap. Also, the force
an expanding column of wax exerts is substantial compared to the size of the
column of wax so you can use it to drive mechanical devices directly.

This principle has been used in a - now defunct - model of insulin pump.

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lmilcin
Nah, just another Rube Goldberg machine.

Deep parabolic mirror, hugely inefficient. Huge amount of materials to control
the orientation.

If you split all the materials, you could have built two collectors facing
different directions. You would not need much more space because a lot is
already wasted. You would get better efficiency because for portion of the
time both collectors would be operation.

I know it is nothing special, but I personally like simple designs that work
dependably.

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MrsPeaches
Nice to see this on here!

Also worth checking out the creator's $30 windturbine [1]

He also runs an active community on facebook around the designs [2]

[1]
[https://opensourcelowtech.org/wind_turbine.html](https://opensourcelowtech.org/wind_turbine.html)
[2]
[https://www.facebook.com/groups/windturbinemakers/](https://www.facebook.com/groups/windturbinemakers/)

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14
I think this is incredibly neat and when I see things like this often wonder
what a person with such creativity could do if they had more free time and
money.

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dmos62
I enjoyed his UN conference interview
[https://www.youtube.com/watch?v=bJGc5Jv6wr8](https://www.youtube.com/watch?v=bJGc5Jv6wr8)
sounds like he spends part of his time doing workshops in the West and the
other doing workshops in the global South, as he calls it.

~~~
VBprogrammer
I really enjoy his videos, however there was one where he created a packed bed
filter and suggested it made the water safe. It certainly makes the water look
cleaner but that is a long way from being safe to drink.

It made me think twice about his credentials.

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redis_mlc
If you expose water to sunlight UV, it will sterilize.

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VBprogrammer
Absolutely, if the sun is able to penetrate (the container is UV transparent
i.e. plastic bottles) and there aren't large clumps in the water which protect
the pathogens from exposure. Which would make a packed bed filter a reasonable
pre-filter before bottling and leaving in the sun for a number of hours.
However, that wasn't what he said in the video, which was that the water
hadn't been tested but was probably safe to drink.

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pontifier
I once saw a very elegant solar tracking mechanism with no moving parts. The
panel array was hinged to swivel freely. 2 solid tanks sat below the fore and
aft edges, and were connected by a solid copper tube.

As the sun moved though the sky, if one tank got more light, a working fluid
would move from one to the other moving the center of mass. This caused the
panel to swing to bringing them back into equilibrium.

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dmos62
Can these mechanisms recover from cloudy periods?

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WalterBright
I suspect one can do something like this with a bimetallic strip that bends
when heated, which can move the collector. You'd also need another bimetallic
strip in the shade so that the movement is based on the temperature
differential, not the temperature value.

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fheld
The same machine but in action (time lapse)

[https://www.youtube.com/watch?v=Lva3bm3psyI](https://www.youtube.com/watch?v=Lva3bm3psyI)

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JoeAltmaier
OR, instead of a parabola, use the same space and cost in materials to aim
several solar panels in different directions?

Not really 'tracking' but neither is the OP I don't think. Relies of the
parabola to correct for angle. But sacrifices available surface area.

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maxerickson
Single axis tracking is typical.

