The idea of “sailing the tide” came about during a regatta as the leading boat. Approaching a narrow sound the enormous forces of water compared with air – became crystal clear!
The large 107sqm spinnaker was catching the wind from astern, whereas the opposite tidal current managed to halt our sailboat via the sleek and polished hull.
We tried trimming the sails, but to no avail, and as we resigned it dawned on me; “-what if we turn the sailboat upside down, letting the spinnaker catch the tidal stream?
“Nothing” would to stop us then, -and this soon became the start of Tidal Sails:
The original “Classic” PCT/NO2004/000367 (Figure 7 and Figure 8) was a complex, primarily drag based, freely suspended 4 loops and two stations ropeway plant. The principle encompassed continuous deployment, attachment, detachment and storage of 1000 sails from/to the two station magazines every tidal cycle. The “Classic” proved to be a challenge both with regard to mechanical functionality and rope wear, but incorporated an advantageous mooring solution.
TidalSails “Classic”, first prototype deployed in 2007, abandoned in 2009 The “Triangle” PCT/NO2010/ answered these challenges and replaced the Classic in 2010, but
it came with the disadvantage of a more complex mooring system and a long return channel.
Tidal Sails “Triangle” prototyping in 2011, abandoned in favor of TackReach in 2015.
The “Self-Adjustable & Variable Pitch Sail Control System”; PCT/NO2012/050178 was boldly implemented in our prototype demo, and the solution proved to be a great success!
TidalSails “Classic”, first prototype deployed in 2007, abandoned in 2009
Tidal Sails “Triangle”prototyping in 2011, abandoned in favor of TackReach in 2015.
By implementing the advanced, autonomous SA&VP Sail Control System, the Triangle was further simplified. During the months “Balder” was operative, the sail control system proved exceptional performance and stability, with inherent dampening effects on any vibration or swinging action when it was provoked to the system.
Triangle prototype “Balder” was a success, with net outputs close to Betz’ limit of 59.3 % recorded during vigorous testing in Skjoldastraumen.
By coincidence “Balder” also proved its capability of tacking against the current. One night the ropes locking the system were ripped by the strong current, and next morning the system was running in reverse, tacking against the current to our big surprise!
The fact that the tacking sails overcame the mechanical friction, gearbox and generator was a remarkable discovery.
This eventually, led to the development of the far less complex, lower weight, higher efficiency and lower cost principle: “TackReach”P27221NO00
The NEW refined BeamReach solution!
The radical, patented technology platform to extract clean energy from “slow moving water” of tidal streams, rivers and ocean currents has become the crescendo of 15years of successive innovations by Tidal Sails AS.
BeamReach combines ancient principles of ocean sailing with state of the art alpine ropeway technology. The patented “sweet spot” configuration will surpass all known tidal technologies as regards extraction efficiency, cost to capacity ratio and environmental friendliness.
A typical plant infrastructure consists of 4-600 Aluminium sails (wings) attached to two steel wire rope loops strung between two freely suspended Direct Drive Generator Stations.
The sails pull the ropes by reaching the first leg before jibing about the opposite station and then reaching back to the first station, while rotating the 4 large direct drive generators
BeamReach exposes a significantly larger surface area into the energy stream than any other known tidal energy technology, but yield the same efficiency per area as typical tidal turbines,
The Full Scale demonstration with loops of 500 m length will be deployed in a natural laminar tidal current of about 2m/s or 4 knots, well below what is presently considered attractive by competing technologies.
The plant will be connected to the 22kV Hammerfest Energi power grid, less than 100 meters from the plant. Further, the project will provide in-depth information on installation, operations and decommissioning costs, as well as “reliability and survivability” in the harsh climate of the arctic.
The project has been awarded a Permit from the Norwegian Water Resources and Energy Directorate (NVE), a Power Purchase Agreement and Letter of Support with Hammerfest Energi, and an Exclusive Sponsorship Agreement with the Norwegian Coastal Administration, incorporating three man months into the project free of charge!
BeamReach produces power on both legs employing different Angle of Attacks due to the higher design AoA on the downstream leg versus the upstream leg. The Variable Pitch assures the all important Peak Shaving.
The relatively higher sideways load generated by the leeward sails, due to the higher AoA yields a greater horizontal catenary than the upstream leg. This elegantly assures safe spacing between the two legs, which also minimize the inherent “Fence Effect” of the first row of sails, identified via the “Gyda” test rig in 2011.
Well before the ropeway load capacity is challenged by the high sideways load a high Angle of Attack provokes, each individual sail autonomously decreases pitch, thus reducing excessive sideways load. 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 a yachtsman easing out his main sail in order to not overpower his heeling sailboat in strong winds).