Renwable energy Ideas

Ideas and Brainstorm needed about ==>Renewable energy Develop a system for very poor people in the developing countries. the system should not be more than 1,500$ US dollars. This system will have to generate electricity OR generate energy that could be stored in a battery. Also you can improve on a system that is already exists or develop a system that could be integrated into those poor people daily life. Other than using a wind turbine, what else can we develop? How is it going to work in details How is it efficient why is it good Statistics on how much energy will be generated and others useful statistics $25 MAX