Cumaru ist predestined for the use of renewable forms of energy. The cooking gas is expensive for the many poor people, there are many power cuts and few firewood. But in Cumaru there is a lot of energy, you just have to pick it up: There is often a strong wind on the hills, the sun shines mercilessly during nine months of the year, and in agriculture a lot of organic material accrues. Here are some ways in which renewable forms of energy can be used (not yet available in English, but in Portuguese or German, except:)

Homemade Wind Generator

Homemade Wind Generator

Solar Cooker with Parabolic Reflector, Construction manual (3 Youtube-Films)

If you want to make a template for a solar cooker with parabolic mirror, the following Excel Tool calculates the datas.

One of the still inadequately solved problems of solar cookers with parabolic reflectors is the tracking of the reflector with changing sun position. Unique in the world is the following program presented here, which calculates on which days the parabolic reflector has to be tilted at which angle from his vertical position. The document can be opened only with OpenOffice Calc.

Calculation of the Position of the Sun in Tropics (xlsx)