Introduction: Use Stellarium (software) to Aim Solar Cookers.

Solar cookers usually need to be aimed "ahead of the sun" but that is not as easy as it sounds.  Look up at the sun, where will it be in an Hour?  It doesn't have a trail or pointers!  But with stellarium, you can find where it will be in an hour  on your computer and then adjust your solar cooker stand to point exactly at that location.  This is far more efficient than guessing and generally guessing wrong.

Comments

author
rimar2000 (author)2012-07-19

I an hour, the sun will be (almost) exactly 15 degrees toward the west along the same meridian. The error is irrelevant for a solar cooker.

If you mount equatorial the rotating axis, you have only one movement to keep.

author
rimar2000 (author)rimar20002012-07-21

The problem with equatorial mounting is the food pot. If you move it and the parabola together, you need a complicated mechanism to allow the bowl be always horizontal. I resolved that doing a solid grill that remains still while the parabola rotates. That arrangement serves from dawn to sunset.

For box cookers, the need of focusing is very lesser, because it collects solar heat although the solar rays come oblique. A parabola, instead, needs to be refocused each 10 or 15 minutes.

author
gaiatechnician (author)rimar20002012-07-20

Hi, Rimar, this video is mostly for people with box cookers or panel cookers where they do not need super tracking. But instead of super tracking, most people use "stupid tracking"! They just guess! When the sun is up at 30 degrees above the horison in the sky in the morning, are you sure it is going west? I have combined 2 screenshots to show its direction. Looks like it is going due south at the times shown but also going much higher in the sky. So someone with a box cooker would probably tilt it a bit to the west and loose a whole bunch of efficiency!
I have tried to convince people to use equatorial mount for about 5 years!
Most people have refused to do equatorial mount and use crazy guesswork to "figure out" where the sun will go next. This at least gives them a chance to put it on a "gun turret" mount and be on a somewhat scientific footing. I have done a replacement video at http://www.youtube.com/watch?v=Nz2uANGGuBM and I think it is better.

30degreesandhour.jpg

About This Instructable

1,043views

8favorites

License:

Bio: I am a stone mason. My hobby is making new solar cooking and gardening stuff. I have used solar heat to cook soil for a ... More »
More by gaiatechnician:Trompe and airlift pump model for schoolsDIY Constriction Airlift Pumpswater flea water filter for fishpond!
Add instructable to: