Other sources --- Two interesting possible sources of energy are salinity gradient techologies and piexoelectric materials. The first one uses differencies on sea salinity for produccing electricity as a chemical battery does. Second one uses especial materials that produce electricity when presure or vibrations are apply on them. A pathway covered with this materials, for example, can produce elecricity using footsteps of pedestrians

Source author: Carlos Arturo Garcia Bonilla carlos.garcia@cancilleria.gov.co