Revolutionary Solar! Stirling engine mount + Liquid piston tracker

[locouk]

If you've left a solar shower in the sun too long the water gets scalding hot, and makes me think this idea is over engineered.

[gaiatechnician]

@locouk It was trying do a low tech alternative to a Scheffler solar cooker. In the Scheffler system, the dish itself deforms every day to produce a new parabolic dish with a new focal point. ( because of the changing seasons). I still work on it when I get time off on sunny days (very rarely) A team designed the Dolios Solar Cooker with 2 focal points BUT they do not have it on equatorial mount. Much harder to aim! I am just one guy, Teams get further, but maybe mine is simpler.

[piespokladowy]

Interesting idea!

What do You think about my Stirling idea?

[stosism]

Like your ideas Brian. I have experimented with tracking systems similar to your dripper system, using strings/cords, and thought you may be interested in an improvement. One of the problems I had was with wind pushing the panel/platform to one side or the other. The strings just bend and don't hold the platform rigidly. I'm thinking of using linkages instead, similar to a car piston. One on either end of the platform's axis, with floats attached to their ends, floating in water.

[gaiatechnician]

@stosism Great that you are experimenting!

My experiments were a couple of years ago. It was very rigid. There are different types of string and some are loosey goosey elastic and I do not think that is any good. I used some sort of fishing line. I used 2 floats in 2 buckets and they were fairly snug fitting and they were not light.

It was way more rigid than I expected! I want to quit solar experiments, do I owe the "community" a few more? Cob and soilblocking is where the fun is!

[gaiatechnician]

Another note, Instead of 2 half dishes, perhaps a counterweight above one half dish would work? The counterweight is just to bring the center of gravity back onto the focus. rimar2000 in instructables used a small counterweight ABOVE the dish in one of his designs. (I cannot give urls here). So the frame around it would remain, the counteweight is solidly attached to the dish and the dish and counterweight are one unit!

[gaiatechnician]

Just a note that David Williams on alt dot solarthermal tried to calculate the exact size of a parabolic dish in balance on its focus, (in answer to a post about this mount). And he found e the natural log base, one of "Gods Numbers" in the ratio of the rim radius divided by focal length! . I quote, "It came out to approximately 2.718 times the focal length. When I saw that number, I was startled, because I recognized it as the value of "e", the base of natural logarithms!"

Neat, eh? Brian

[hantides22]

You are the man.

[trailkeeper]

It would be cool if you can make a design something like this for a PV pannel.

[gaiatechnician]

There is one, it is the one from March 4th.

It is actually much easier with PV pannels.

[trailkeeper]

I like the concept of it all. A few things I would probably do, and you probably already know this, is to keep the mirrors fixed/non-adjustable in position and just move the systems angle (at that pole angle board) so that the Suns rays are still perpendicular to the mirror. Basically for added simplicity if done manually each day or two. I'd probably just use a one mirror system also, but I guess it helps cooking two things at once sometimes.

[gaiatechnician]

I thought that too at first but you CANNOT move the systems angle. It must be at your latitude pointing towards the nearest pole. The problem with a one mirror system (that I ran into a couple of years ago with the tracking solar accumulator) is that the center of gravity goes out of whack with seasonal adjustment. But with 2 mirrors, you move one one way and you move the other the other way for seasonal adjustment and one movement cancels out the other one so the center of gravity stays put.

[Jon70]

@gaiatechnician I know there are some technicalities of how the earth rotates and apparent changes in sun elevation, but something is possible, maby if the mirror is also slightly adjusted along with the main angle.

[gaiatechnician]

Hi, Jon, you might get a close approximation that wyah

some of the time. This is the only way to get it work accurately all of the time.

Brian

[trailkeeper]

Well, maby what I said would work better with a trough heater. I know what your saying though because the elevation of the sun does change throughout each day from 0 up to the max. angle for that day., and therefore, the mirror would have to be adjusted throughout the day also. For simple systems, like the box cookers, it is possible to adjust them manually. Even at the equator, the sun changes 47 degrees total throughout the year.

[gaiatechnician]

I have equatorial mount, the same as telescopes that can track the stars or the sun easily. Actually the 47 degree change happens everywhere! The system I show works everywhere on earth. The only difference is that your angle of the axis of rotation must be the same as your latitude.

Brian

[giuliano170]

sweet

[danie1murphy]

Perfect, a wonderful concept.

[wizardangel]

cool concept...a bit too windy here though for slow suntracking with this design ..but in a wind sheltered area would be great..we get gusty 35mph winds often,,blows down the cornstalks,lifts the loose tiles from the roof..but this concept of yours looks very workable ,thanks for the share .

[gaiatechnician]

I think you underestimate the power of the liquid piston. The gusty wind has to lift the float out of the water. And it can be a fairly tight fit into its container. So also you get turbulence at the sides as the float gets sucked up. I did dripper trackers a couple of years ago with small floats. They were way more stable in the wind than I expected!

(For my tracking solar accumulator project). About 1 meter of collector area and two 14 (6kg) pound floats kept it stable. Thats tiny!