Tidal Energy
What is it?
The motion of large bodies of water can be used to turn
mechanical devices to produce electricity. Tidal energy
exploits the natural ebb and flow of coastal tidal waters caused
principally by the interaction of the gravitational fields of the
earth, moon and sun.
How does it work?
Tidal power falls into 3 main categories:
- Tidal Stream generators: make use of the
kinetic energy of moving water to power turbines, in a similar way
to wind turbines use moving air. This method is becoming more
popular because of the lower cost and ecological impact compare to
tidal barrages.
- Tidal barrage: make use of the potential
energy in the difference in height (head) between high and low
tides (in a similar way to hydro electric power
plants). Barrages are essentially dams across the full
width of an estuary. They are very costly, there is a
shortage of appropriate sites worldwide, and have an impact on the
ecology of the estuary.
- Dynamic tidal power: exploits both the kinetic
energy of moving water and the potential energy of the difference
in water levels. Very long dams are built from coasts
straight out into the sea or ocean without enclosing an area.
Is it suitable?
Schemes are costly and may take years to construct.
No power can be generated until they are complete, hence long
payback periods.
Putting barriers into waterways, particularly
highly diverse estuaries (often the most feasible for tidal power
sites) can have adverse effects on natural habitats, impacting on
sedimentation and erosion, water flow, salinity and overall water
quality.
Some of the ideal sites for tidal power
generation are not located in areas where electricity demand is
high.
What are the benefits?
- Unlike wind or solar power production using tidal forces is
constant as it is less vulnerable to weather or seasonal
variations.
- No waste is produced.
- Basically it needs no fuel to operate.
- Tides are more predictable than wind or solar
power.
- Long-term operating and overhead costs are
very low compared to conventional energy sources.
Contact Us
Climate Change Officer
Property, Leisure and Waste Management
White Cliffs Business Park
Whitfield
Dover
Kent CT16 3PJ
Email: energy@dover.gov.uk
