The technical director and co-founder of Marine Current Turbines (MCT), the Bristol-based company that designed and developed the world’s only commercial scale tidal stream turbine – SeaGen – reports that it is now running at full power and fully automatically, as planned (OE August 2003).
Peter Fraenkel told a Lisbon ocean power conference: ‘We are delighted with SeaGen’s performance. It is running reliably and delivering more energy than originally expected in an extremely aggressive environment. It should be remembered it is being driven by a wall of water 27m deep that surges back and forth with every tide through the Strangford Narrows in Northern Ireland at speeds of up to 10 miles per hour. We are getting more energy than expected mainly because the resource is more energetic than originally predicted during earlier surveys.’
SeaGen had already delivered over 350MWh of power into the Northern Irish electricity grid, he said. The twin generators typically produce an average of 5MWh of electricity during the 61/4 hours of each ebb and each flood tide, enough energy to meet the average electricity needs for 1500 homes.
The SeaGen turbine, with its twin 16m diameter rotors, is officially accredited as a ‘UK power station’. Although it was operational for most of 2009, it was not until September that consent was given to operate it without having to have environmental scientists (marine mammal observers) on board and onshore. This was an initial requirement under the licensing arrangements to ensure that SeaGen did not adversely affect the marine mammals that are a protected feature of the local waters and restricted SeaGen’s uninterrupted running. However extensive experience gained so far suggests the seals and porpoises are not at any significant risk and as a result SeaGen is now permitted to operate unattended and by remote control, as was originally intended.
For the time being, an operator onshore will continue to monitor a sonar image of the passing flow which can show up any seal that ventures too close to the rotors, and the operator has the facility to stop the machine. As confidence and the body of evidence grows, it is expected that full running will be permitted in the near future.
MCT managing director Martin Wright said his team are working to deploy tidal turbine arrays in UK and overseas waters. ‘We are working on new scaled-up developments from SeaGen that promise to generate power at a lower cost,’ he said.
‘The expectation is that this radical new technology can be developed within five to ten years to make a significant contribution to future energy needs. Given suitable market incentives, SeaGen demonstrates that marine renewable energy is at the cusp of forming the basis for a new UK industry with considerable worldwide export potential.’ OE