Improving the ovens is an endless task. Can we make the box more air-tight? Can we find more reflective aluminum?
Stateside, we partnered with the mechanical engineering design programs at Michigan State University and Purdue University. Students have attempted to develop an oven that is lighter, less expensive, and more efficient, using only domestic Tanzanian materials. That has proven to be a challenge. Mirror finished anodized aluminum would make the oven heat faster, but it is not available in Tanzania. Nor is clear tempered glass available for the box lids. So, the program searches for local solutions.
In Tanzania, the solar team has found a better rubber seal for the ovens, using the rubber seal found around landrover windows. They are using a better aluminum than the lithograph plates, which were very fragile and needed frequent repair.
The oven cost is high — $100 to produce and distribute each oven. An intense education program is included in this cost, to insure that people understand how solar cooking works, and to help them in the first months using the ovens. The cost is about 20% of the annual income in the area. So, Joyce Liundi and her colleagues have been very creative about distributing the ovens.
Until we create or discover a less expensive oven, we will focus on distributing solar lamps.