Answer the following question given this paragraph: 

Moving water has energy ( Figure above ). That energy is used to make electricity. Hydroelectric power harnesses the energy of water moving down a stream. Hydropower is the most widely used form of renewable energy in the world. This abundant energy source provides almost one fifth of the world’s electricity. The energy of waves and tides can also be used to produce water power. At this time, wave and tidal power are rare.


Q: Hydroelectric power harnesses the energy of what?


A:
water