Solar Barbecue, finally an experiment!

This was a test run to see if it could be done. If I did not build it, I would never have appreciated the problems or guessed at solutions. I have since moved away from parabolic dishes. Other dish types can more easily be adjusted for the seasons.
How I made the mould, the reflector and set up the equatorial mount for all day solar cooking, drying or heat accumulation.

Category:

Science & Technology

Tags:

• diy
• environment
• gadget
• mechanics
• solar
• CO2
• renewable
• energy

[MrXstacey]

use aluminium foil tape or in my case I used fake chrome decal material for my shiny surface, experience tells me thinner strips are better than wider ones due to bubbles from trying to apply the reflective material to a curved surface, but yeah I had the same problem that you did first time 'round

[gaiatechnician]

Have you seen the "point focus" videos? A guy uses 2 troughs to concentrate light to a point. You can use a whole sheet of mylar with no cuts! You lose a bit of power because you reflect the light twice but you gain simplicity.

It is much easier making 2 troughs than one dish. and it is certainly easier to make a large trough than a large dish.

Also, there are no secondary focal points when it is out of focus. (A parabolic dish can produce a lower power focus at a distance! DANGER!)

[hempseed57]

So is this your full time oven? When i was a kid in scouts we had little versions of solar ovens, but nothing so complex. It was just cardboard and tin foil and 20 hungry kids waiting around for the food to get hot. But seriously nice work and way to use your noggin.

[gaiatechnician]

I made it last year to see if it could be done. There were problems. The biggest one was center of gravity. You have to lever the dish forward or backwards as the sun moves up and down with the seasons and I did not have a good counter weight strategy.

I used a dripper tracker (which actually worked well) but I think it was only good for 6 or 7 hours of tracking. You need something taller than a large paint can for tracking. I dismantled it. No space!

It could be done better for sure.

[gaiatechnician]

The compound parabolic dish works really well!

I get 90C every sunny day in a 7 liter pot of soil. This steralises it so I can use the soil to grow seedlings with no weeds or bugs in the soil to destroy the little vegetables.

I will eventually use a compound parabolic dish to make a more usable and much more reliable solar tracking barbie.

[gaiatechnician]

It worked but it was a first attempt and I made several mistakes in the process. You gotta realize how much there was to doing it. I had to invent the "mechanical mathematician" and figure a way to know how to point the dish AND get tracking going. It showed that it can be done.

I steralised soil in it for seedlings for a couple of months. (~ 15 liter batches) going to about 70 degrees to kill weed seeds.

I took it apart for the next experiment. A compound parabolic dish. (Not yet made). C

[YouAdamNazzkl0wn]

OMG- 9 minutes and we didn't cook anything!!

So- does it work?? Can you put the pots on the dish??

[gaiatechnician]

I now use an aluminium pot covered with barbecue paint and it is quite a lot better.

I was not too concerned with efficiency in the experiment. It was more proof of concepts than anything. Low tech tracking works, an off the center dish works, now it is up to back yard diy people and industry to respond.

I did this with junk and dirt and old pallets and a full time job.

Imagine what you could do in a modern shop with welding tools! You could make sweet equatorial mounts, and polished product

[jeremusic]

cover the outside of your pot with candle soot for much better heat absorption