We baked a long loaf of bread in a metal tube heated up by sunlight focused by tin foil.
The tube oven heated up over 300F and the bread was baked in 30 minutes.
This device is very cheap to build and can allow people in developing nations to cook everyday without using fuel. This device requires no maintenance and will function day after day.
Appears on these pages
Deutsch, Ελληνικά, Español, Esperanto, Français, Indonesian, Italiano, Kiswahili, Kreyòl...