Phase change thermal storage: Cooking with more power and versatility

Abstract

A 100 W solar panel directly powering an Insulated Solar Electric Cooker (ISEC) can slowly cook 5 kg of food over the course of a day. However, 0.4 kWh of the day’s energy can be stored in 2.5 kg of erythritol phase change material, allowing ISEC to cook more rapidly, as well as cook after sunset. We control supercooling by forcing crystallization, making erythritol an ideal thermal storage material for cooking and other thermal-storage processes, but the erythritol degrades in quality when cycled for several months over 180 °C. The efficiency of thermal storage is comparable to that of more expensive systems using battery storage and induction cooktops. ISECs can be built in low-income communities, and the best design varies depending on availability of materials, access to building technologies, and local preferences. A Global Learning Community of researchers, funding agencies, nonprofits, student groups, and local enterprises is collaboratively developing the open source technology with partners in low income communities to optimize designs, construction, and dissemination.