Tidal Flashcards
Features of Tidal Energy
Predictable, intermittent, specific locational features required
Tidal power
A method of generating electricity using the tidal water flow caused by the gravitational forces between the Moon and Earth.
Tidal barrage
A tidal power scheme where a dam-like barrage is built across a bay or estuary so that all flowing water flows through the sluice tunnels in the barrage causing the turbines and generators to turn.
Tidal lagoon
A tidal power scheme where a section of a bay or estuary is impounded by a seawall which has sluice tunnels and turbines like a tidal barrage. The environmental impacts are lower than those of a barrage as it only covers part of the bay or estuary.
In-stream turbines
Tidal turbines that are rotated by marine currents, but without having a barrage to focus the water flow.
Tidal range
the difference in height between high tide and low tide
Spring tide
where the gravitational effect of the moon and the sun combine to form tides with the greatest tidal range
Neap tide
where the gravitational effect of the moon and the sun work in opposition to form tides with the smallest tidal range
Advantages of tidal power
Time and range is predictable, large electricity output compared with other renewables
Disadvantages of tidal power
Intermittent, few sites suitable for barrage construction, large environmental impact of lagoons and barrages on sensitive estuary habitats
Environmental impacts of tidal power
loss of habitat, embodied energy of construction materials, sedimentation behind the barrage, concentration of pollutants, migration barrier
New tidal power technologies
tidal reef schemes where water can continue to flow over a submerged barrier
