Water: energy from moving water
Hydraulic energy is the force created by moving water: rivers and tides, as well as ocean currents or waves.
The hydraulic energy of rivers has long been harnessed by watermills. In modern-day hydroelectric power stations, the flow of water is used to drive turbines that generate electricity (15% of all electricity produced in Europe). Building dams does not create pollution as such, but some can have an impact on the environment in which they are built (submerging wide areas of land, disrupting the flow of certain watercourses).
Other technologies (tidal power, the use of waves and ocean currents) are still in their infancy, but appear very promising.
