Thread: Solar Energy

But we don't have any sun to power it, or do you have some there???

in between showers.

this is the best climate in oz

did you see the epsiode on myth busters on solar dishs they used a old sat dish and covered it with mirrors and worked a treat thought could use it to heat water but not sure how you would go with tracking the suns path

I have a "Mother Earth News" Magazine that I have lent to my daughter which would be 27 years old that has a design for a solar furnace that will actually boil water and make steam and it actually tracks the sun and at the end of the day swings back ready to pick up the sun in the morning.

It has all the details of how to construct it.

I can't post a picture of it because I have to get the magazine back from my daughter.

So, are you gonna build one, Bob?

Same site has links to some other good stuff, including furniture for disabled.

Back to the mirror: I didn't study the mechanism too closely, but might work better with motion pre-aligned. I have a book around here someplace on sundial design and construction. Could enlighten the setup; as is, it seems to be more hunt & peck.

Joe

Friends of the Earth here in Sydney used to have a BBQ made this way. Could be 25 years ago. Worked fine. Scaled up there are all sorts of possibitlities for boilers etc.

The best designs I have seen are mirrors in an arc so that they dont need to be constantly aligned. I remeber the Mother Earth article as well Barry,

Sebastiaan.

Making one is a possibility if I reckon I can pull 5hp out of it. That'd run a decent genset, Free r/c cooling in summer

Here is a link to some pictures of the "Mother Earth News" solar furnace.


http://www.motherearthnews.com/gallery.aspx?id=66298

Here is a link for all the backyard scientists who want to enter a global competition www.live-edge.com to win some big bucks

Hi Echnidna,
couldn't get your solarforge link to work - so I don't know if this is the same - the Teton plans include collecting the heat - I think he used it to heat his house in winter.

A Tracking Solar Concentrator for the home experimenter, file: solarhom.htm, 11/11/99

Cheers,
Bob.

Originally Posted by citybook

Hi Echnidna,
couldn't get your solarforge link to work - so I don't know if this is the same - the Teton plans include collecting the heat - I think he used it to heat his house in winter.

A Tracking Solar Concentrator for the home experimenter, file: solarhom.htm, 11/11/99

Cheers,
Bob.

Bob

Solar tracking worries me just a little as regards a domestic installation. If the system malfunctions it can effectively be the equivalent of staring into the sun with consequential eye damage.

I mentioned in another thread that I was worked with a man who had been involved in a 5MW commercial, pilot scheme in America.

When they first commisioned the system they decided to blank off the collector plates as a precaution. This turned out to be just as well as, when turned on, the panels pointed in every direction possible. The central control tracking system had malfunctioned. They may have damaged the sight of everyone in the vicinity.

The control system needs to be really good if it is to be safe.

Regards
Paul

Hi Paul,
granted safety is a big issue - but if you want to build something with "forge" power then there is some danger.

The Teton type of reflector focusses back along the angle of the incoming light - in Toowoomba that's about from 39' to 85' above horizontal.

The reflector is on a post at least as 2m high, so the reflected beam should always be higher than a person.

The reflection is not a parallel beam - it's a 3D cross centered on the target, which is about 2m out.

So past 5 or so metres out the beam strength at any point in the sky is one mirror - ie. no more than incident sunlight.

ie. the danger zone is a sphere with a radius of about 2m centered on the target (not the reflector).

If you don't climb up on a ladder and stick your head into that sphere it should be Ok.

The pivot can have limit stops, ensuring the reflector stays in the designed space.

And you could put a safety fence to prevent kids climbing on the structure.

An anecdote in support of your point - one of the problems they had with the Solar II project in California was that birds flew into the hot spot - game over for the bird - and the animal welfare crew gave the operators heaps.

Cheers,
Bob.

Thanks for the additional info on that Bob. Perhaps Solar 2 could have had a side line in cooked "chooks, pidgeons etc."

Regards
Paul

could try one of these.

Solar Furnace Plans