Last months work! Rocket stoves (cocinas moviles) won first prize at a sustainable engineering competition. Stoves are easy to build, no tech skills required, use all local materials, and are portable. They conserve approx. 70% of firewood decreasing deforestation and wood-smoke contamination. And the folks in my community love them. Total cost: app. $9 per stove. Sustainable without NGO or outside support or finances.