Which term describes energy sources like wind and solar that are replenished naturally?

• A. Nonrenewable Energy
• B. Fossil Energy
• C. Nuclear Energy
• D. Renewable Energy

Answer: (D)

Energy sources that replenish naturally on human timescales are called renewable energy. Wind and solar fit this because the sun continuously provides energy and atmospheric conditions keep producing wind, so these resources can be harnessed repeatedly without depleting them. This is different from nonrenewable energy sources, like fossil fuels, which take millions of years to form and are used up faster than they can be replenished, and from nuclear energy, which depends on finite uranium fuel. So wind and solar are renewable because their underlying sources are ongoing and effectively inexhaustible for our purposes.