Solar Dryer Trays That Turn Themselves

Solar dryers reduce harvested produce to a storable, sellable form. Trays are loaded, turned during drying so material dries evenly, checked repeatedly for dryness, and unloaded when done. All of it is manual and all of it repeats every day the sun is out.

Two separate problems in one place. The physical handling costs hours of labour per day and does not get cheaper as the project grows. And judging dryness by hand and eye is unreliable: under-dried produce spoils, over-dried produce loses weight and value.

Commercial drying equipment with automated handling and moisture control exists and is priced for industrial processors. It needs stable mains power, spare parts from a city supplier, and a technician when it breaks. On a working farm with unreliable grid power and no technician within reach, that equipment becomes an expensive shed ornament within a season.

• Branch — Mechanical, with Electronics on the sensing and control side.
• Technical skills — Mechanism design, fabrication and welding, materials for outdoor use, solar and battery power, sensors and microcontrollers, calibration, cost engineering.
• Other skills — Measuring a process before changing it, designing for repair, working alongside people who will use what you build.