Another renewable source is biomass and is a biological material produced from living organisms and their byproducts, such as food waste, wood, excreta etc.
An excellent biomass is now considered the human waste.
More companies are turning to renewable energy from biomass.
The anaerobic digestion is the best method, which produce biogas, comprising of methane and carbon dioxide, which is used directly as cooking fuel.
The advantages of using human waste is that this will help protecting natural resources when the resultant product is used for cooking, fueling and will benefit to lower the greenhouse effect.