Any sort of sustainable food plan that involves a garden and/or fruit trees needs a good dehydrator. This in conjunction with some canning and some animal protein can get you through any low production season.
Here is a solar dehydrator that uses a solar heat collector and dc powered fans to push hot air through the dehydration chamber. I built without plans and based the size of the solar collector on how the beer cans would fit in when stacked up. The fans aren’t needed, but can improve the air flow. They use so little wattage; they can run off of a small 10-15w solar panel. Or you can plug them in.
Step 1: Sizing the Solar Collector
Gather some aluminum cans of your choice, measure the boards based on the sizing of the cans and the number of rows you'd like. My box was 117cm x 69cm. I used a variety of different can sizes. I also used a treated lumber since this will be sitting outside all of the time. I used 2x4's for the entire construction.
Step 2: Build the Frame
Based on the size of your collector, build the dehydration chamber frame so that the collector can lean up against it as seen in the finished picture and be mounted on the inside of the frame.
Step 3: Roof Supports and Solar Collector Mounting
Cut 2 diagonal beams for the roof mount and make a cut in the 2x4's on the solar collector to allow it to notch into place as seen in the picture.
Step 4: Solar Collector Bottom and Air Vents
Next you'll need to make a bottom. I used DensGlas, an outdoor rated gypsum board. Then you'll need to add your vents. You want air to move freely so don't put vents where there are going to be cans in the way. If you use fans, you'll want to cut holes based on the shape of fan you use.
I used "CoolerGuys" dual blower computer cooling fans from Amazon. They're variable speed and built to be used in a hot environment so I thought they would be good for this application.