This lecture briefly focus on How does Recycling Save Energy. The energy required to manufacture paper, plastics, glass, and metal from recycled materials is usually less than the energy required to produce them from new materials. The steps such as collection, processing, and transportation is also usually less energy then the steps in supplying new materials. By recycling just 1 ton of aluminum cans, we conserve more than 207 million Btu, the equivalent of 36 barrels of oil or 1,665 gallons of gasoline.