The Solarflower is an open source solar energy collector you can make easily using scrap materials. It is able to follow the sun using a non-electrical mechanism.
It can be made anywhere from common salvaged materials using basic tools, is portable, has no running costs or emissions, and can produce up to kilowatts of power.
The solorflower works by generating heat. The heat can be used do other things such as generating electricity, smokeless cooking, heating and purifying water, making charcoal, and anything else that heat could can be used for.