Renewable energy is energy generated from natural resources—such as sunlight, wind, rain, tides and geothermal heat —which are renewable (naturally replenished). Renewable energy sources can be replenished in a short period of time. The five renewable sources used most often are:   ...

  Wind power Airflows can be used to run wind turbines. Modern wind turbines range from around 600 kW to 5 MW of rated power, although turbines with rated output of 1.5–3 MW have become the most common for commercial use; the power output of a turbine is a function of the cube of the wind...

  In the past, renewable energy has generally been more expensive to use than fossil fuels. Plus, renewable resources are often located remote areas and it is expensive to build powerlines to the cities where they are needed. The use of renewable sources is also limited by the fact that they...