Below is a link to a Mother Earth News article that includes plans to construct your own highly efficient solar food dehydrator.
"Nearly two decades of expert testing, experimentation and refinement have gone into producing these solar food dehydrator plans. The resulting food dryer isn’t just efficient and off-grid — it’s also highly cost-effective for anyone wanting to preserve large amounts of food at home."
Article link: https://www.motherearthnews.com/diy/tools/solar-food-dehydrator-plans-zm0z14jjzmar
Dennis Scanlin is a Professor of Technology and Environmental Design at Appalachian State University in Boone, N.C. For 30 years, he has coordinated the university’s Appropriate Technology Program where he and his students have built and tested many renewable energy systems.
Source: Scanlin, D. (2014, July). "Best-Ever Solar Food Dehydrator Plans." Mother Earth News. www.MotherEarthNews.com