Tidal Sails AS, an independent, privately held closed corporation based in Haugesund, Norway brings to market a ground breaking technology to extract kinetic energy from slow moving water, by combining the ancient principles of ocean sailing with state of the art alpine ropeway technology, to generate low cost electricity.
Tidal Sails has carried out a range of theoretical and numerical studies over the years. These have been validated by several prototypes and test rigs.
The 4MW TackReach exceptional extraction efficiency, its prospects for cost reduction, maintenance and environmental friendliness are all noteworthy. The energy converter is a series of extruded aluminum sails, attached to wire ropes strung across the tidal stream at a certain angle at 15m depth beneath shipping lanes.
RiverSails is a similar solution for unidirectional currents like rivers and ocean currents.
The sail profiles reach with the current and tack back in between two freely suspended Direct Drive Permanent Magnet Generator stations. The power plant exposes a much larger surface area into the energy stream than any other known tidal technology, thus facilitating cost efficient energy capture from slow moving currents.
Self Adjustable & Variable Pitch sails autonomously self-adjust to optimal pitch according to current speed. In strong currents with concurrent high sideways loads, excess power is bled off in order not to compromise structural integrity of the ropeway system – similar to easing out the main sail not to overpower the sailboat in strong winds.
A full scale demonstration will take place at a consented site in the ethnic minority, Sami community of Kvalsund, Northern Norway. The 4MW TackReach “Aegir”, with its 500 m length and 400 fully sized sails will be deployed in a tidal current of about 2m/s or ca. 4 knots, well below what is presently considered exploitable current speed by competing technologies who presently aim for 8 -10 knots sites. (A 10knots current represents 125 times the energy density of a 2 knot current.) Slow moving currents of 4knots are readily available, in contrast to the tidal energy “hot spots” exploited by typical tidal turbine solutions, which are scarce and far between. Current speeds lower than 4knots (2 m/s), accounts for an estimated 99% of total tidal resources worldwide, while currents above 4knots are rare and far between.
Several well recognised partners are involved in the project, including the global market leader in the fields of gondola and ski lift systems, Doppelmayr, who has concluded full scale friction and wear testing of the wire system, and sail attachment tests. The aluminum extrusion giant Norwegian Sapa has developed the sail solution, and German Setec delivers the Power Take Off system. Austrian Teufelberger delivers the rope solution, while Norwegian Global Maritime is responsible for the mooring and installation. As a result of hard work, determination and strategic technological development, the company and its partners are finally ready to move forward with the first full scale installation following a decade of developments via the first drag based system, then a triangle based solution was developed and tested before present streamlined TackReach solution came about, completely outperforming the previous superior solutions.
The demonstration project has a 4MW Consent from the Norwegian Water Resources and Energy Directorate (NVE), and a Power Purchase Agreement with Hammerfest Energi, Norway. The Norwegian Coastal Administration (Kystverket) has extended an exclusive Letter of Support granting TidalSails 3 man month free consultancy service sponsorship. The consortium expects the First Commercial power plant to generate electricity at the exceptional low cost of 0.05 €/kWh by 2020, and a Letter of Intent with a field developer in the UK has already been signed.