In recent decades, technologies have been developed that harness the energy of the sun, the wind, the earth and even the ocean. While current supplies of coal, oil, and natural gas are finite and will eventually run out, wind and solar are examples of renewable energy. These sources are not limited and can be tapped indefinitely.
The concept of sustainable energy or green energy embraces practices, policies, and technologies that provide energy at the least financial, environmental and social costs. When these costs are factored in calculating life-cycle costs for fossil fuels, sustainable energy options make an even more compelling case for long-term strategic applications.
Types of renewable energy: