Alstom (formerly TGL)
Alstom has been present in the ocean energy market since 2009. In 2013 it completed the acquisition of Bristol-based Tidal Generation Ltd (TGL), which was established in 2005.
TGL developed a 500 kW tidal stream turbine – Deepgen – which was successfully deployed and connected to the grid at EMEC’s tidal test site at the Fall of Warness in Eday in September 2010. In March 2012, TGL announced that the device had generated over 200MWh into the national grid since installing their device on site.
Alstom subsequently developed a second generation 1MW tidal tubine turbine, with a nacelle consisting of a 3-bladed, upstream pitch controlled rotor with an epicyclic gearbox, induction generator, frequency converter and transformer. The turbine exports grid compliant power at 6.6kV via a three-phase wet mate connector mounted in the base of the turbine. This configuration is analogous to a wind turbine subsea.
The Alstom turbine design features:
- Simple, efficient to install and maintain – the nacelle buoyancy means that it is easily installed and retrieved in a single tidal cycle using small vessels, reducing installation and maintenance costs.
- Intelligent nacelle – a thruster intelligently rotates the nacelle to reflect the direction of the tide, managing ebb and flood tides seamlessly and maximising energy production.
- Efficient blades – turbine blade pitch is actively managed to control load on the turbine and optimise use of tidal conditions locally.
In 2013 Alstom deployed the 1 MW tidal turbine, on the same tripod support structure as the 500 Kw, in a project partnership with the Energy Technologies Institute (ETI), known as Project ReDAPT (Reliable Data Acquisition Platform for Tidal). This project aimed to collect and publish significant data in order to further the tidal energy industry as a whole during an 18 month test period. There’s a link to the ‘Fall of Warness 3D Model Validation Report’ on the ETI website, alongside a link to various other ReDapt reports in the right hand column of the ETI ReDapt page.
In July 2013, the 1 MW turbine generated at its full nominal power and in November 2014, Alstom reported a total cumulative export in excess of 1GWh. In 2016, GE completed the acquisition of Alstom, with designs for a next-generation 1.4MW ‘Oceade’ tidal turbine in planning.
Alstom ceased testing at EMEC in 2016.