Under Water Kites
Minesto develops a new concept for tidal power plants called Deep Green. Deep Green is based on a fundamentally new principle for electricity generation from tidal currents. The power plant is applicable in areas where no other known technology can operate cost effectively due to its unique ability to operate in low velocities. Minesto expands the total marine energy potential and offers a step change in cost for tidal energy.
The principle of the technology can be explained as a two stage process.
The first stage increases the relative flow speed entering a turbine. When the tide hits the wing it creates a lift force, since the kite is mounted to the ocean bed with a tether and is controlled by a rudder, the kite can be taken in the desired trajectory, here in an eight formed path. The method increases the flow velocity into the turbine by 10 times, compared to the actual stream velocity.
The second stage uses a generator to convert kinetic energy into electrical power.
The net result is increased power from a smaller package. The planned normal full size weighs only 7 tons excluding anchoring which gives an energetic payback time of 3 weeks, compared to 8 months for onshore wind.
The test confirms power production of the plant at Marin in Holland.
Potential: 800 kW per kite
First project: Anglesey, Wales/UK (Holyhead Deep)
Project size: eventually 80 MW
Span width kite: 12 meter
Argument pro under water kite: one needs 15 times less material per generated kWh as compared to wind turbines