Tidal turbine. Diagram showing the principles behind the tidal turbine power station. Large water turbines are anchored to the bed of an estuary or channel where strong currents accompany each tide. The blades of the turbine can be turned by the water whether the tide is coming in or going out. As the turbine blades turn, they power generators that create electricity. Tides are a very reliable source of electricity, although large turbines need to be protected form shipping and fishing nets.