Investor Presentaiton
Energies 2019, 12, 3658
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because their cumulative energy generation will be smoother than the energy production of a single
device [59]. Efficient power production is strictly dependent on the advanced control systems.
3.2.2. Tidal Range Energy Conversion
Tidal barrage power plants use the difference in the height of the water surface during ebbs and
floods (tidal range) to drive common hydro turbines. The greater tidal range results in higher energy
extraction by the power plant.
Figure 7 presents the principle of the tidal barrage power plant [109]. The shapes of structures
are similar to dams and the structures are built in the estuary or bays to store water at high tide.
A difference in water height at the internal and external sides of the dam occurs due to changes in the
tidal regime. Three main tidal barrage schemes are
●
Flood generation—the power production process starts as the water enters the tidal basin
(flood tide);
• Ebb generation-power production starts as the water leaves the tidal basin (ebb tide);
Two-way generation—the tidal power plant produces power during the flood and ebb tides.
The sluice gates on the barrages are utilized to control water levels and flow rates. In general,
ebb generation is generally more efficient than flood generation. This is due to there being more
kinetic energy in the upper half of the basin in which ebb generation operates. This is because of
the effects of gravity and the second filling of the basin from inland rivers and streams connected
to it via the land. The bi-directional tidal turbine generators are generally more expensive and less
efficient than unidirectional tidal generators [110]. Some studies related to the tidal barrages' dynamics,
power performance, and economy can be found in [111–115].
(a) Flood generation
Sea
(b) Ebb generation
Sea
Tidal barrage
WL
Turbine
Tidal basin
Tidal barrage
WL
Turbine
Tidal basin
Figure 7. Tidal barrage principles.
3.2.3. Tidal Current and Ocean Current Energy Conversion
The kinetic energy of both tidal and ocean currents can be extracted with hydrokinetic turbines,
which have similarities with wind turbines but are still submerged. Due to the higher density of waterView entire presentation