Answers.comÂ® is making the world better one answer at a time. The element that makes the strongest material is carbon, and the material which is made is graphene. Thao Hg.
<br /><br /> Solar power is the cheapest renewable energy source for small-scale use, such as pocket calculators, LED lights, and remote (small) electrical appliances. Hydroelectric power is the cheapest renewable energy source for large-scale production. That is, it has the lowest cost to construct and maintain the generating facilities compared to the amount of energy produced.
Technologies for harvesting and storing alternative energy are all evolving so quickly that it's difficult to say which new alternative energy source is the cheapest. Today's promising technology may be surpassed by something even greener tomorrow.