Higher Performance Solar Crop Dryer Kit for Developing Economies

EPA Grant Number: SU833509
Title: Higher Performance Solar Crop Dryer Kit for Developing Economies
Investigators: Tatara, Robert A.
Institution: Northern Illinois University
EPA Project Officer: Nolt-Helms, Cynthia
Phase: I
Project Period: September 1, 2007 through September 2, 2008
Project Amount: $9,933
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2007) RFA Text |  Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , P3 Challenge Area - Agriculture , P3 Awards , Sustainability


Solutions to hunger and farming problems have been sought throughout the world but especially in developing nations. After battling growing issues, the final obstacle is crop drying. The drying of harvested crops is necessary so that the crop may be processed, stored, and delivered to the consumer with a minimal amount of loss due to spoilage or insect attack. In the best case, fossil fuels are used with drying systems. But for farmers in developing countries, extremely low income cannot overcome increasing fuel and energy prices; furthermore, in many areas electricity and fossil fuels are not available at any price. Thus, a large segment of the world’s population relies on simply setting the crop out in the sun. However, such non-concentrated solar energy may not be sufficient to adequately dry the entire crop. Further, this also results in long drying times where the crop, laid on mats, trays, or the ground, is exposed to bacteria, bird and insect attack, dust, wind dispersion, and other environmental factors. Any innovation to reduce drying times will speed the time to storage and thus protect the crop.

It is proposed to design, build, and test a novel solar crop drying system based on the compound parabolic concentrator (CPC) concept. It is an improvement over open-ground drying by providing crop protection and concentrated sunlight to speed the drying process by a factor of at least 3. The ultimate goal is to design towards a kit form so that this system can be easily distributed throughout the world.

This project enhances P3 sustainability by offering an improved methodology for drying crops. This novel, proposed solar system takes advantage of a blackened surface to improve solar radiation collection at the crop; a covering film to reduce thermal losses as well as minimize bird and insect attack, dust, and wind dispersion; and concentrating limbs to increase collector efficiency, temperature, and decrease drying times. Thus the system uses proven technology while simultaneously minimizing mechanical complexity. The limited mechanical components keep costs low, make installation easy, and part replacement locally feasible. In all, the proposed system satisfies all the requirements for use in developing nations of initial low capital costs, easy to construct, easy to operate, without complex mechanical and electrical components, more effective drying than ordinary open sun drying, easy to maintain, and simple part replacement.

To develop a prototype design, at this stage, testing at NIU is required to investigate the relationship between parameters such as drying rate, crop moisture content, air flow, length of drying time, and solar intensity. With this information, the design can be optimized and a kit can be proposed.

The project will be implemented through a student team as part of the engineering and technology curriculum at NIU. Capstone design classes offer an opportunity to complete this proposed project. These courses are design-oriented and interdisciplinary.

Supplemental Keywords:

agriculture, crop drying, solar energy, compound parabolic concentrators,

Progress and Final Reports:

  • 2008
  • Final Report