Advanced Technology
Verdant Power has conducted in-water testing of the Free Flow System at the
RITE Project since 2002, advancing the system to the current 5th generation (Gen5). During 2006-08, Verdant demonstrated the Gen4 Free Flow System at RITE, representing the world’s first operation of a grid-connected tidal turbine array and successfully demonstrating the technology as an efficient source of clean energy with the following outcomes:
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Grid-connected power with no power quality problems
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Fully bi-directional operation with high efficiency on both ebb and flood tides
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Automatic control and continuous, unattended operation
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No fouling or damage from debris
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9,000 turbine-hours of operation
Operational and environmental monitoring data gathered through this demonstration formed the basis for Verdant Power's application to FERC for its pilot license application, as well as advancement to the Gen5 system. Further advancements and testing at RITE in 2012 advanced the composite rotor design.
Gen5 Rotor Test at RITE - 2012
Energy Generation at RITE
The East River is a tidal strait with strong water currents that change direction between flood and ebb tides approximately four times each day (with periods of little or no flow between tides, called “slack tide”). As shown in the figure below, when the water velocity exceeds approximately 1.0 m/s (3.3 ft/s or 2 knots), the turbine blades begin to rotate and the units generate electricity for approximately 4.5 hours (red areas in figure). As the tide shifts direction, the turbines yaw (turn approximately 170 degrees) to generate power from the current flowing in the opposite direction. This cycle repeats in a very predictable manner approximately every 6 hours. The regular nature of tidal currents provides a significant advantage for tidal power as compared to other, less predictable resources like wind and solar power.