2. Tidal energy
Some of the oldest ocean energy technologies use tidal power. Al coastal areas in the world have
at least experienced high and low tides within 24hours. For those tidal differences to be
converted into electricity, the difference between high and low tides must be more than 5
meters. Currently there are about 40 sites on Earth with tidal ranges of this magnitude (i.e.
Atlantic Northeast regions and the Pacific Northwest).
Tidal energy production is divided into three main technologies thus;
•Barrages/Dams
• Tidal fences
•Tidal turbines
3. Barrages/Dams
•A barrage/Dam is used to convert tidal energy into
electricity by forcing water through turbines which activate
the generators
•Turbines and gates are installed along the dam and when
the tides produce an adequate difference in the level of
water on the opposite side of the dam, they are forced
open
•Water then flows through the turbines and turn an
electric generator to produce electricity.
4.
5.
6.
7. International Environmental Experts What makes Tidal Energy different to its
study competitors?
• They estimate that there is over 59 • Davidson Hill technique of generating
Terawatts of power available through tidal energy from any moving form of moving
energy in the United Kingdom alone that water e.g. ocean currents and rivers
remains unutilized • In 2003 it marked the highest efficiency
ever produced from a water turbine
8. • It is renewable and sustainable
Advantages
• More energy obtained from the movement of tides i.e.
seawater is 832 times denser that air which means an 8
knot tidal current has more energy than a 380kph wind
“Tidal Energy has one of the
• Once a turbine is installed, tidal energy is free
smallest footprints of any
renewable energy resource” • No expensive fuel is required
Dr. David Suzuki • Very low maintenance cost
• Tides are predictable many years in advance (reliable)
• Most dense compared to any renewable energy source
• Low cost for energy produced
9. Disadvantages
• Affects the local ecosystem (Death of marine birds and
animals)
• Distracts sea life migrations
• Construction is very expensive
• Causes silt build up
• Small costs per kilowatt-hour is not competitive with
conventional fossil fuel power
