Sun isn't at important as wind. The sun can destroy a lot of nutrients. So depending on what you're drying, sun might not be advisable. I did do this however with some cooked pinto beans. Why dehydrate beans you ask? Well, I work away from home outside except in the winter months. I'm prepping now to be on the road until October. If I cook my beans or rice ahead of time, then dehydrate them, I can actually re-hydrate them in a black or metal container with some water and seasonings, in my car on the dash from the sun or quickly cook over a rocket stove if the weather isn't cooperating. It saves a ton of money.