Floating Tidal Turbine Arrives in Orkney - 11 March 2011

This week sees the arrival in Orkney of a full scale prototype floating tidal turbine, the SR250, which has been designed and developed by Stromness-based Scotrenewables Tidal Power Ltd. The arrival of the device marks the successful completion of the latest phase in the development and commercialisation of the company’s innovative tidal turbine concept. The philosophy behind the design is ease of installation, access and maintenance. All installation and operational activities can be undertaken using a standard multi-cat work vessel which has the advantage of being readily available and relatively cheap compared to offshore anchor handlers or jackup barges. The company previously has received financial backing from the Carbon Trust, the Scottish Government and more recently has attracted substantial private inward investment from Fred. Olsen Renewables and energy company TOTAL. Ultimately the goal is to focus on undertaking commercial deployments in sheltered tidal sites and ‘run-of-river’ projects worldwide.


The results of 1/5th scale device testing, which concluded in August 2010, informed the final design of the 250kW device, which has been constructed and commissioned by Scotrenewables staff over the past 6 months at Harland and Wolff in Belfast. The build has been completed in record time and within budget.   While many of the team were occupied in Belfast, a small number of engineers remained in Orkney at the beginning of the year to install the mooring system and a new subsea cable at a specially selected site at the European Marine Energy Centre (EMEC) testing facility near Eday. Taking advantage of relatively calm weather for the time of year, the mooring system was installed in 16 hours, and the 3km of subsea cable laid in approximately 20 hours.

While the operations at the EMEC test site will be critical in the testing programme, due to the nature of prototype testing the device will undergo intermittent testing at the test site and will not remain onsite permanently. Chief Technical Officer Mark Hamilton explained “the SR250 is an intermediate scale device built to undergo a series of sea trials in and around Orkney waters over the next 2 years. We will gradually increase test durations onsite at EMEC as confidence is built in the performance and handling of the device. A major advantage of our floating technology is that can be easily towed to and from site for inspection and maintenance at harbour side. During the test programme we will be carrying out regular trips to and from our test site at Eday to our maintenance operations base at Hatston Pier in Kirkwall. We are aiming to collect a few months of data in different environmental conditions from this prototype to inform the design of a larger commercial version.”

Managing Director Barry Johnston was keen to stress the importance of approaching the project in carefully managed incremental stages stating that ‘we still have a lot to learn and having the ability to test the SR250 in open-sea conditions will provide the team with the crucial experience needed before progressing on to the full-scale prototype, 2MW commercial device. It is however very unlikely that the future deployments will be within the Pentland Firth as we plan to focus our efforts on more sheltered sites and run-of-river opportunities worldwide. The SR250 prototype is the result of a tremendous effort by our team of dedicated engineers who all deserve to be congratulated for their efforts particularly over the past six months.’