The community solar cooker concentrates the sun’s rays.  Each parabola reflects the sun’s rays laterally toward its focal point situated at the interior of the kitchen.  A kettle of up to 80 liters is placed either in the focal point or directly next to the focal point (in which case one uses a secondary reflector) where the blackened exterior surface of the kettle absorbs the concentrated light and transforms it into heat.  The inside of the kettle is heated.  If the kettle is well-insulated, the process will be accelerated.

Example of a solar kitchen installed in 1992 in Niancongo, Kenya in a boarding school of 350 students :

The kitchen is composed of 5 parabolas.

1.      Wood consumption in the previous system:

(270 days/year) * 108 kg of wood/ day = 29,000 kg of wood/year.

2.      Wood consumption in the new system:

a.       218 sunny days per year * 18 kg/day = 4000kg/year                  

b.      54 cloudy days per year* 73 kg/day = 4000 kg/year                   

Previous system :  29,000 kg wood/year

With a Solar Cooker:  8,000 kg wood/year

Savings:  21,000 kg wood/year

Note that at a boarding school the students must eat in the morning.  Water for breakfast is heated with the solar energy from the previous day and stored in a well-insulated 200 liter recipient.  In the morning, this water is around 70°C and can be reheated using around 18 kg of wood.