Tidal energy is where the power from the tides is made into electricity. Because of the massive Great Britain coastline and the many estuaries, the tide could provide enough energy for 20% of Britain’s needs. However, there are only eight possible sites where we could build tidal power stations in Britain, which includes the Severn, the Solway, and Humber estuaries.
A huge dam, called a barrage, is built across the river estuary. The barrage built works like a hydro-electric dam, although it is much bigger. The barrage works when the tide goes in and out; the water goes through holes in the dam. When the water goes through, it turns a turbine.
On the barrages, because of ships, they have to build large lock gates, like ones used on canals If a dam was built across the Severn Estuary, the tides would not go out as far. However, the rubbish which the Severn carries would stay there a lot longer.
- It is completely predicable – the tides change regularly
- Once it is built, it is free, and the dam is not very expensive to maintain
- It needs no fuel
- It is reliable
- It doesn’t give off waste
- The tides are only active for 10 hours each day – when the tide is moving in or out
- If a barrage were built across an estuary, the environment around it would be changed, for kilometers up and downstream.
- There are not many sites available for this type of energy
- A barrage is very expensive,