Tides that produce power, anyone?
A former Royal Navy sloop – the HQS Wellington – now moored on the Thames at Temple Steps in London, will undergo a two-month trial for an innovative energy capture technology that uses a tidal energy turbine.
If successful at generating an adequate amount of electrical energy, the company that owns the turbine, Nautricity, hopes to develop a tidal energy farm that generate enough electricity to power some 35,000 dwellings.
Authority to launch the test has been issued by the Port of London Authority. The HQS Wellington presently operates as a stationary home for the Honourable Company of Master Mariners and is operated by an educational charity, the Wellington Trust.
According to a Nautricity press announcement, dated May 18, 2011, the tidal energy trial involves siting hundreds of tidal turbines along the river from Westminster to Margate. According to the company, the largest of these turbines is capable of generating up to 500kilowatts of electricity.
The project has been developed by Thames Tidal Ltd, a joint venture involving Nautricity Ltd, a tidal technology developer, and Energy Invest Group, a global developer and financier of energy projects.
On its website, Nautricity writes: “The CoRMaT second generation tidal turbine is innovative and proven technology employing two closely spaced contra rotating rotors, driving a contra rotating electrical generator.”
The company states the first rotor of the turbine features three blades rotating in a clockwise direction while the second rotor, located directly behind the first, counts four blades rotating in an anti-clockwise direction (see attached illustration).
Nautricity claims this design “…can double the relative rotational speed compared with a single rotor turbine.” Translation: the turbine has the capacity to directly drive a flooded, permanent magnet, and contra-rotating generator, without any kind of gearbox.
The water then cools the flooded generator. “The magnetic field acts across the rotor and rotating-stator sections of the generator as a “differential”, equally splitting the torque between the two rotors, writes Nautricity. “Reactive torque acting on the supporting structure is eliminated allowing the system to be moored rather than rigidly attached to the seabed.
The turbine can be deployed in water depths ranging from 8 to 500 meters.
While the concept of capturing such energy from the oceans sounds great, reports of success to date have not been abundant. In 2007, a set of six submerged turbines were designed and submerged to capture energy from the East River’s tidal currents. But the project did not grow into a second stage of development that called for the launch of 100 such turbines. More recently, the citizens of Eastport, ME plan to capture electricity from the tides.
Should the HMS Wellington trial prove successful for this version of tidal turbine, it is reasonable to expect the development of many maritime green energy companies locate in suitable water environments subject to tidal movement.
May the force of the tides be with all experimenters.