May 15, 2005
Harvard Engineering Student Completes Report on Kinkajou Power Supply Prototype
A human-generated power supply system, based on an easy-to-use and readily available foot treadle, can generate enough electricity to power the Kinkajou, concludes Lindsey Cameron, an Engineering undergraduate at Harvard. Lindsey recently accompanied the DtM team to Mali in March for a field test of the treadle design, which she developed as part of her Senior Design Project.
Over the course of the past year, Lindsey has been working to create a proof-of-concept prototype for a sturdy, low-cost alternative to the Kinkajou's existing power supply system, which currently relies on an expensive solar panel and parts not available in Mali. After examining the efficiency and feasibility of other potential energy sources, including hand-cranks and bicycles, Lindsey selected the foot treadle for its low cost, significant energy output, high availability, and user-friendly nature. Her final sytem combines a sewing machine, DC generator, charging circuit, battery, and status light indicators into a cost-effective power supply and battery-charging device. Since almost all villages in Mali already have sewing machines with foot treadles, the design reduces the capital costs required and even presents an opportunity for income generation for the local tailor.
A treadle, with fly wheel and foot pedal
During the field test, Lindsey brought her prototype to 6 villages in southern Mali, where 16 Malians, ranging in age from 7 to 60, tested it and provided valuable data and feedback. The field data suggests that the average user could completely charge the battery in 26 minutes of work, and the majority of users reported that the treadle was easy to use. The device was also tested by a local tailor, who set a record for energy output and loved the idea of another profitable use for his own sewing machine. Lindsey also presented the prototype to World Education and USAID Mali for a design review. Both organizations were impressed by the design's low cost, adaptability, and reliance on local materials, and made several suggestions for how to increase performance and ease of use.
For more details about the treadle design and the results of the field test, see Lindsey's
final presentation [PDF] and project report [PDF].
Lindsey (left) watches as a volunteer tests out the device in Mali
