Tidal power stations take in water from high tides, usually at a river mouth, and then release it using dams or barrages where it drives turbines that produce electricity. Sometimes dams and barrages are not used but turbines are laid in a moving current.
Advantages:
- Tidal energy is renewable.
- The energy produced is clean and non polluting.
- There is no carbon dioxide or any other by-products released. It produces no greenhouse gases or other waste.
- It is a renewable energy that will help reduce our reliance on the burning of fossil fuels.
- There are two tides every day and they can be relied on. The energy is there for the taking.
- So the electricity supply is constant and efficient.
- Once you've built it, the energy is free because it comes from the ocean's power
- It needs no fuel.
- It produces electricity reliably.
- Not expensive to maintain.
- Tides are totally predictable.
- Offshore turbines and vertical-axis turbines are not ruinously expensive to build and do not have a large environmental impact.
- A plant is expected to be in production for 75 to 100 years
- Uses an abundant, inexpensive fuel source (water) to generate power
- May protect coastline against damage from high storm tides and provide a ready-made road bridge
In most cases, nothing can stop tidal flows as they are huge masses of water with lots of energy behind them. As long as the moon exists, and as long as the earth spins, the tides will come in and go out and rotate a turbine - all for an initial upfront one-off cost with a whole pile of maintenance considerations.