Renewable energies are sustainable and do not cause any pollution for the environment while fossil fuels are not sustainable and cause an extensive pollution that damages the environment. Renewable energies are solar energy, wind energy, bio energy, geothermal energy, tidal energy, and hydropower. Approximately all these forms of energy are hampered by their high costs. Moreover, solar energy, wind energy and tidal energy are characterized by their intermittent nature, as they are not available all the time. This intermittent problem can be solved by energy storage. Renewable energy plays an...