Tracking the Sun! for the Solar Accumulating Barbecue

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Introduction: Tracking the Sun! for the Solar Accumulating Barbecue

The sun moves across the sky at 15 degrees per hour. If we could automatically follow it with our solar cookers and solar panels, they would absorb a lot more energy.
Here is an idea of how to do it that might spark your imagination.

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Just a note that I have a diagram  http://solardesign.ning.com/photo/liquid-piston-tracker that people might find useful
and a couple of new videos about equatorial mount (one is on instructables)
Brian

I like your idea about using the least resources possible for controlling your cooker/panels.

Like mentioned below the sun tracker robot looks like it would do a pretty good job of this.
https://www.instructables.com/id/Robotic-Solar-Powered-Sunflower/

Although I am not an electronics expert., I maybe someone could help us out here, but I do have some thoughts on this.

You could utilize one sunflower robot with a vertical orientation. A potentiometer could be mounted to this robot and tied in to a whetstone bridge. Another leg of the whetstone bridge could then be tied to a potentiometer/float in your water.

My thoughts are this: As the robot rotates, it changes the potentiometer resistance which inturn changes the control voltage across the whetstone bridge. The potentiometer float is either adjusted up or down with the addition or subtraction of water from the tub until the voltage is equalized between on the whetstone bridge.

A small PLC or some sort of control circuit be utilized to monitor the voltage change on the whetstone bridge. The control circuit could then operate either two solenoid or proportional valves. One of the valves would let water into the tub and one would release it from the tub.

One problem that may occur is that the waves in the tank/tub would create an inconsistent signal and so the water near the float would need to be protected/isolated from this wave action. The water that is coming into or exciting the tub could be mounted below the expected waterline and at the opposite end of the location of the float. This would help to eliminate the motion of the water. A cover over the water would help to eliminate the influence of the wind or bugs dropping into the water.

I suppose that this potentiometer idea could be tied to your clock or better yet the a PLC's internal clock could control the water level directly with the feed back from the float.

If your interested you can find some inexpensive PLC controls at: http://www.aboutplcs.com/directlogic/ You may be able to set up a PID control system and thermocouple temperature sensors on this if you want to go over the top with this.

I have new water clock "dripper tracker " and clock tracker designs at <br/><a rel="nofollow" href="http://solarcooking.wikia.com/wiki/Tracking">http://solarcooking.wikia.com/wiki/Tracking</a> I am using 2 bucket trackers currently with the outflow from one tank filling the other tank. I have found them to be very stable in windy conditions.<br/>The ideal "tracker" is still the clock or a little arm or winch that lengthens or extends (at 2 or 3 cm per hour in the case of my bucket trackers). As it extends, a plastic pipe drops and water exits from the tank, and this turns the equatorial mount with your panel or solar reflector. The exit water can fill a bottom bucket just like in my dripper tracker videos. The difference is that this one will be much more accurate and repeatable.<br/><br/> This will definitely work and can have automated reset and restart in the morning. Photocells and so forth are overdesign in my opinion. Lets keep it simple. A cheap mechanical sprinkler timer could be adapted for this. <br/>Brian<br/>

I am glad someone mentioned waves in the tank. The thing that would cause the most waves will be wind acting on the reflector or panels. It will tend to pull and push the float. This is something that we will have to live with. Sizing the float and the tank properly is important here. Also important is sizing the pipe that lets the water drain out. It probably needs to be capable of taking just a little more than the per hour rate of water drainage. I also thought something to stop waves between the float and the drain pipe might be necessary but I didnt put it in. (Just wanted to get the basic concept across). Remember also that the critical thing is to turn that axis at 15 degrees per hour. If you can get a good cheap simple way to do that , adjusting your panel slightly by hand every 2 or 3 days will keep it exactly pointed at the sun all day. (and you get minimal 30% more energy). Brian I will look at your links when I get back from holidays. Thank you.

Fantastic Idea! Oh, wait- it has already been done.

Ok then. Perhaps you could give the links to the video or instructable and save us all the trouble? Cheap tracking is a key part of the tracking solar accumulating barbecue project. I have read that Scheffler cookers have often had problems with tracking due to the mechanical parts. This trys to sidestep the problem.

Guess what? here it is.
https://www.instructables.com/id/Robotic-Solar-Powered-Sunflower/
with little effort, it can be adapted to use it in 2 axis.
It's really cheap, and a local boy scout group made a similar project of a solar tracking oven.
The trick is to put photodiodes near, with a black thing between (sorry for my brutal english...), so one will be less exposed to sun then the other, and the system balances itself so they're always facing the sun.
Questions? :)

Sorry if I have not been very nice, but it seemed such an easy task to me! But, you know, things are easy when you already know them! ;)

So, as it is so easy I guess you have done it?