Portable Power in the Backcountry: Design and Development of a Modular Water Heater

With a growing number of outdoor enthusiasts becoming increasingly dependent on electronic devices such as GPS units, cellular telephones, and palm-sized computers, the need exists for a lightweight, field-maintainable electronic power source. Since batteries are neither lightweight nor environmentally friendly, the outdoor enthusiast’s proclaimed advocacy of “environmental awareness” furthers this necessity. As a result, there is a strong desire on the part of the outdoor community to have alternative methods for generating portable power. This paper describes the development of a device capable of producing up to 10 watts of electric power by converting thermal energy into electric energy. This is achieved by placing a bismuth-telluride thermoelectric module between a highly efficient heat exchanger and an integrated cold-water reservoir. In addition to thermal efficiency and eliminating the user’s dependency on batteries: size, weight, and system volume were also critical design specifications. Design efforts have resulted in a pocket-sized, multi-use device, which can be used as a power generator, water heater, or distillation unit. The unit has also been designed to work with equipment already possessed by most outdoor enthusiasts. This paper discusses the design challenges and novel solutions encountered during the successful development of the unit.