ARB Research Seminar

This page updated June 19, 2013

Solar Crop Drying Demonstrations

John C. Hollick, P.E., President, Conserval Engineering Inc.

June 03, 2005
Cal EPA Headquarters, 1001 "I" Street, Sacramento, CA

Research Project


This project demonstrated the use of solar energy, displacing fossil fuels, to dry crops grown in California using the low cost unglazed transpired solar collector. The transpired collector or SOLARWALL system has been installed in over twenty countries primarily for heating commercial and industrial buildings. This project for the California Air Resources Board, under its Innovative Clean Air Technologies grant program, was the first application of the transpired collector technology in the USA for drying of crops and it appears to have been the first significant improvement in solar drying technology since the 1980's.

The presentation will explain the technology, a summary of the five solar drying demonstration installations completed in California, which includes drying of walnuts, pecans, prunes and herbs, monitoring results and the benefits of using solar drying. As the California projects represented the USA contribution to the International Energy Agency Task 29 solar drying project, where the same collector technology has been used, a brief summary of other international drying projects will also be presented.

Speaker Biography

John Hollick, P. E., is President of Conserval Engineering Inc. of Toronto and Conserval Systems Inc. of Buffalo, NY, suppliers of the SOLARWALL solar air heating system. He is a professional engineer registered in Ontario Canada and Delaware, U.S.A. He became actively involved in designing solar air heating systems and formed Conserval in 1977 to market turnkey solar and energy saving projects. In the early 1980's, Mr. Hollick developed the concept of preheating outdoor air in industrial applications by using wall mounted solar collectors. In the 1990's, he patented and introduced the all metal building integrated solar wall heating system, called a transpired solar collector by Dept of Energy. Mr. Hollick has been granted several world wide patents on the various SOLARWALL designs and has received numerous awards for his inventions and projects. Hundreds of SOLARWALL installations are now installed in over twenty countries for ventilation air, space heating and crop drying applications.

For a complete listing of the ARB Research Seminars and the related documentation
for the seminars please view the Main Seminars web page