Tidetec and MJ2 Technologies, a French low head tidal turbine manufacturer, presented a new tidal turbine at Seanergy 2017 in Le Havre, France.
The turbine is specifically engineered to operate at very low heads (1.5 – 4.5m) with a discharge of between 10-27 m3/s. The system has an average tidal head difference of 3-3.5 meters.
The very low head (VLH) turbine currently has over 90 installations, and is therefore considered to be a proven turbine, according to Tidetec, the Norway-based tidal energy technology developer.
The system is intended for small-scale tidal barrage application and the main market the companies are eyeing is installation of VLH turbines in already existing infrastructure, like barriers intended for flood protection, ship-locks, unused drydocks or other small tidal pools.
With the new concept, Tidetec and MJ2 Technologies are also looking at retrofitting new turbines to old tidal mills, since the system requires a modest tidal head to function.
The VLH turbine is very suitable to Tidetec’s turning device, as it is very compact, and requires no inlet and outlet tube. This enables the turbine to be turned with only a simple frame with an axel, instead of the Tidetec turret, the company explained.
Furthermore, one of the advantages of the new turbine is that it is one of the most fish-friendly turbines on the market, according to its developers, who added that the system also has a very low visual impact, because of the compactness of the turbine. In addition, the turbine is almost completely silent due to the low rotational speed.
“Since our system focuses on already existing infrastructure and the VLH turbine requires very little civil works compared to other hydro turbines, the environmental impact is also low in this area. For enclosed pools with limited water exchange, our system has a positive environmental impact – enabling more water exchange between the pool and the sea,” Tidetec stated.
Tidetec and MJ2 said they are currently looking for an ideal demonstration site, and are already in discussions with some promising demonstration sites in France.
To remind, Tidetec’s recent tidal energy activities include initial engineering for a 20MW turbine system with a 7m diameter turbine runner, carried out together with engineering companies FEMKUBER and HUGG, and prior to that the company concluded a two-month long testing of its prototype tidal device in Svelvik, Norway.