- November 2014: Brian White reports: "I have a thing in the works for solar drying with calcium chloride as a desiccant. Dry calcium chloride absorbs water and becomes liquid in the water that it absorbs. It actually has a pretty complex series of crystal hydrates that all absorb water, and calcium chloride is cheap and food safe. So, I am planning to use a solar cooker to drive off the water and "recharge" the calcium chloride. My main problem with solar cooking is that I am rarely home during the day. Using a solar cooker to build up a big store of very dry calcium chloride to dry fruit in the fall might be a good idea. Then you put the calcium chloride in a closed solar dehydrator with the fruit and a little fan and the water gets transferred to the calcium chloride, which drips out of the thing as it becomes liquid. I am also looking into making calcium chloride from limestone and brine. It can be made with a solar panel electrolyzing the salt. You get hydrogen and chlorine that you can recombine above in moist limestone chips. This converts some of the calcium carbonate in the limestone to calcium chloride. This might seem like a waste of a solar panel, but the industrial process to produce calcium chloride is similar."
- October 2014: Bernhard Müller is working on the development of a counter-current solar food dryer which saves 50% on space and materials compared to common solar tunnel dryers. Involved in the development are Faustine Odaba of NAREWAMA, John Amayo of SURE, Prof. Wilson Ogola of the Technical University of Kenya as well as some experts from Uganda.
Sizzling Solar Systems dehydrator
Heating the thermal mass (water bottles) to help provide stable nighttime temperatures and avoid mold formation on the fruit.
- November 2012: Solar Food Dehydrator - Stan Cajdler of Brisbane, Australia, has developed a solar food dehydrator, which significantly reduces the formation of mold spores caused by the nightly cooling of food. Typically, the drying process can last for several days for successful solar food drying. In this design several water containers (for thermal mass) are positioned in the lower chamber of the dehydrator. As the collector plate heats up, it heats up the surrounding air, which rises through the drying chamber. During the day, radiant heat from the collection plates also heats the water containers, which slowly release heat overnight. This overnight thermal air movement through the upper chamber dramatically reduces the formation of mold spores. For more information on Stan’s solar cooker designs check out: Sizzling Solar Systems
UC Davis team demonstrating the solar dryer.
- October 2012: Foresight Technology has developed a lightweight, large-capacity portable solar food dehydrator. It is highly effective. Its unique four-sided absorber design allows for an extended daily drying period. It is available for shipping.
- February 2011: A group from the UC Davis Program for International Energy Technologies installed a solar box dryer for drying fruit in Nicaragua. They worked with the local organizations Grupo Fenix and the Solar Women of Totogalpa. They also connected with students and faculty at the Alternative Energy Program at Nicaragua's National Engineering University and the directors of the new dried fruit export company SolSimple. They plan to send a follow-up trip during the summer of 2011. More Information...
- May 2006: John Maina of Kenya wins the Energy Globe Award for 2006 – Employing solar energy for drying food & gaining income security. In Kenya, 30-40% of vegetables and fruits are lost due to poor post-harvest handling. The lack of firewood, which is necessary for drying and treatment of durable goods, is one of the major reasons for the loss. Since 2002 SCODE (Sustainable Community Development Services) has employed a solar dryer in Kenya for the drying of harvested produce. The advantages are obvious: solar energy is free and available virtually everywhere. The fresh produce can be made durable in a cheap way and market value will be increased. As a result of the fast drying process, the farmers can raise harvesting production and are therefore able to generate additional income – this means up to 50% more productivity. The time needed for collecting firewood before can now be used for various other activities and deforestation is reduced as well. Currently 30 solar dryers have been installed and 920 farmers have been trained in their use. Thirty craftsmen have also been trained in the construction and installation of these solar dryers. The project contributes to an overall improvement of living conditions, family nutrition, environment protection, and income generation. At the moment the project is implemented in the Rift Valley in Kenya and has the potential to be duplicated in other areas.[1]