Open Hydro

OpenHydro Open Centre Turbine at EMEC tidal test site (Credit: Mike Brookes-Roper)
Established in 2005, Dublin-based OpenHydro was the first developer to use EMEC’s tidal test site at the Fall of Warness. It’s test rig and 250 kW open centred turbine were installed in 2006. The device was the first tidal turbine to be grid connected in Scotland and subsequently the first to successfully generate electricity to the national grid in the UK.
The test rig consists of two steel monopoles grouted into sockets drilled into the seabed, with a platform suspended from the piles to provide a working area. To aid navigation, the test rig is painted yellow and a yellow light (solar powered) is fitted in accordance with NLB requirements. The platform is also equipped with an AIS transponder.
The turbine, which was six metres in diameter, was fixed to the piles using two steel collars, which allow the unit to be lowered into the sea using two 15 tonne hydraulic winches. The test rig allowed the turbine to be raised out of the water easily, reducing the cost and time for testing, maintaining and updating the device.
As the Open-Centre Turbine was designed to be deployed directly on the seabed using a gravity base, OpenHydro placed a blank, non-grid connected turbine on the seabed adjoining their test rig using the specially commissioned “OpenHydro Installer” in summer 2008.
Whilst progressing larger demonstration projects in Canada and France, OpenHydro continued to bring subsequent generations of its device for testing on the test rig at EMEC. Its 7th generation 6m diameter turbine was installed in April 2014 and accrued over 10,000 hours of run time.
Unfortunately OpenHydro’s parent company, Naval Energies, made the decision to liquidate OpenHydro in July 2018. The turbine was removed in 2022, and platform decommissioning completed in 2024.
The platform decommissioning project, contracted by EMEC, involved a range of marine services. A joint venture partnership was formed in April to deliver the contract, combining Ocean Kinetics’ divers, riggers, welders and ROV services, and Green Marine’s offshore management, vessel, moorings and cable experience, with shared responsibility for operational engineering, cutting and heavy-lift operations.
Key work included dismantling the platform’s steel superstructure – including two 18-tonne steel piles, drilled and grouted into the seabed – as well as cable disconnection and termination. Pile foundations were cut to the seabed using reversed Diamond Wire Cutters, returning the seabed as close as reasonably practicable to its original condition.
Q&A with Sue Barr, OpenHydro, 2016
What challenges were you facing prior to testing at EMEC?
Prior to testing at EMEC, we lacked the facilities to test, refine and prove our technology at scale in a real live tidal environment.
Since we started testing at our EMEC platform in 2006 we have gained invaluable insights into how our technology operates in the marine environment in real time; something which cannot be fulfilled through other forms of modelling or lab testing.
Why is it important to test in real sea conditions?
It was important for us to test and validate our technology, as well as to improve efficiency and performance through our work at EMEC. We also were able to test our components and sub-components and how they would function in a real marine environment. Testing at a facility such as EMEC is important not only in terms of refining our turbine and power system, but also more broadly in terms of showcasing our technology to potential investors and clients.
How has your time here at EMEC helped resolve these problems?
Our research structure at EMEC has proved to be a key facility for us. The intelligence we have gained through our highly instrumented turbine has given us important insights into loadings, turbine performance and maintenance.
It has also provided us with important environmental monitoring information on how marine life interacts with our technology. Our turbine system at EMEC is easily accessible, allowing us to inspect the turbine and turbine components at regular intervals.
What were the results?
We regard our work at EMEC as being an important step in the OpenHydro journey. In December 2015, our latest turbine at EMEC passed the 5,000 hours generated into the Orkney grid milestone. In addition to this, we have secured efficiency improvements in the region of 16% through the work we have done to refine the turbines control system. The power conversion system and components we have used at EMEC during the last few years have provided us with validation for the power conversion technologies we are using on our projects in Cape Sharp, Canada.
Related news
- December 2024: OpenHydro decommissioning complete
- July 2018: EMEC statement on OpenHydro liquidation
- December 2016: Class of 2016
- September 2016: Exciting progress for EMEC tidal graduates
- August 2013: Busy week at Fall of Warness
- August 2013: Unprecedented tidal energy activity at Hatston Pier
- September 2008: OpenHydro successful deployment with specially built barge
- May 2008: OpenHydro become first grid connected tidal device in Scotland
- April 2008: OpenHydro winter test programme provides invaluable information
- October 2007: OpenHydro turbine swap
- October 2007: Tidal test site opening
- February 2007: Successful installation of first tidal turbine