Scotrenewables Tidal Turbine Generates Power - 26 July 2011
Testing of the SR250 tidal turbine took a major step forward last week as the device generated power for the first time. This marks a major milestone for the team at Scotrenewables Tidal Power Ltd who have been developing the floating turbine from their base in Stromness.
The floating tidal turbine has been visible at Hatston pier for several months while it has been undergoing commissioning since arriving in Orkney waters in April. The first power generation is the most significant milestone to be met since an initial grid connection of the turbine at the EMEC test site shortly after the device arrived in Orkney. Chief Technical Officer Mark Hamilton explained “we’re very happy to be reaching the end of the commissioning process and to be generating power. Successfully producing power from the turbine means that the many different electrical, mechanical and hydraulic subsystems are all working well together. Progress has been steady since we got the machine home to Orkney and we are delighted to now be looking towards the next stage of testing in the Fall of Warness.” The 250kW machine is to undergo a 2 year test program at the EMEC test site near Eday.
The device generated power for the first time during tow trials with the MV Voe Viking in Shapinsay Sound. Equally as important as generating power for the first time, the tow trials have proved that the primary design criteria of building a tidal turbine that can be easily handled with a modest sized work boat has been met. The team plan to take full advantage of the ease of handling and connecting/disconnecting the device from its moorings by regularly bringing the device back and forth to Hatston pier for maintenance and inspection over the 2 year testing program.
Managing Director Barry Johnston said “at every stage of building and testing the SR250 we have learned invaluable lessons that will feed into the design of our commercial scale 2MW device. Producing power for the first time is of course a major step forward, but I am equally pleased with the lessons learned by the team while commissioning the turbine in Hatston and the experience we are building up of handling the device at sea.”
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.’
Scotrenewables award contract for manufacture of 250kw Tidal Turbine (SRTT) prototype.
Harland and Wolff Heavy Industries Limited have been awarded the contract to build the latest cutting edge prototype tidal turbine by Orkney based Scotrenewables.
The 30m long 250kw device is approximately a 1/4 scale power take off model of the full size device. The prototype will be manufactured in Belfast before being deployed at the European Marine Energy Centre (EMEC) test facility in the Orkneys.
Harland and Wolff Engineering Manager Fred Black said, ‘Harland and Wolff have been very active in the renewables market for many years now and Scotrenewables tidal turbine belongs to a small group of developers who have concentrated not just on the conversion technology, but importantly on making the device easy to install and maintain. Our input was to assist their engineers develop the design to make it production friendly. This makes it cheaper to manufacture and enhances quality.’
Scotrenewables’ Managing Director Barry Johnson said, ‘We’re delighted to continue working with Harland and Wolff on this important development. The Scotrenewables Tidal Turbine is a major step forward in marine renewables and this large scale model is a massive step toward proving the productivity, reliability and importantly the ease of operation and maintenance that is inherent in our design.’
He continued, ‘Each full-size SRTT will be circa 43.7m long with a draught to the rotor axis of 11m in operation mode. The rotors will be 12m diameter for the 1.0MW prototype device. The SRTT concept is designed for deployment in any water depths of >25m and mean spring tidal velocities of 2.5m/s to over 5m/s which covers 70% (Carbon Trust, 2006) of the UK tidal resource. In the transport mode the maximum depth of the SRTT is limited to 4.5m to allow access into most harbours for maintenance.’
Harland and Wolff Manufacturing Manager Trevor McCormick commented, ‘We’re delighted to be involved in this project. We have a strong track record in the marine renewables sector and understand the importance of this prototype and the trust that Scotrenewables are placing in us. We look forward to working with them and seeing the prototype prove itself.’
Some key benefits of the technical features include:
• Floating design – enables turbines to be in region of typically highest tidal velocity
• Compliant Mooring System - enabling deployment in deep waters
• Passive Yaw System – improve energy conversion, simplify design
• Fixed Pitch Rotor Blades – to reduce design complexity and cost
• High performance, low mass
• Rapid connection/disconnection
• Maintenance carried out inshore/in harbour
Figure 1 – SRTT Operation Mode
Figure 2 – SRTT Transport/Survivability Mode
Harland and Wolff Heavy Industries Limited
Tel +44(0)2890 534389
Tel: +44 (0)1856 851641
Construction of a 250kW Tidal Turbine Begins - 17 July 2010
Local company Scotrenewables (Marine Power) Ltd, have made considerable progress in the development of their floating tidal energy device, by signing a contract with Harland & Wolff shipyard to construct a full-scale prototype of the Scotrenewables Tidal Turbine. Work on the SR250 tidal turbine has already begun with installation at the European Marine Energy Centre scheduled for March 2011. Speaking at the All Energy conference in Aberdeen, Project Leader Mark Hamilton said he was pleased with the progress so far and was looking forward to seeing the full-scale device in Orkney waters. “This stage of the project is particularly exciting as after years of successful numerical and physical model testing and development we have now placed an order for the full-scale device. This is a great achievement for us and is testament to the hard work and dedication of all the team. There is a lot of hard work left to do in proving the long-term viability of our technology, but testing to date has produced very promising results. The market for our technology both in the UK and worldwide is huge – we aim to be at the forefront of the future tidal energy industry.”
This marks the end of a long phase of scale model testing, which began several years ago, using a number of scale model versions of the device. A 1/40th, 1/20th and 1/7th scale model have been tested in laboratory conditions whilst latterly a larger 1/5th scale model has been tested in Burra Sound between Hoy and Graemsay. This phase of testing was a steep learning curve for the team providing the crucial experience of operating a tidal turbine in Orkney’s open sea conditions. Mechanical Engineer William Annal explained “our aim is to produce a device which incorporates survivability with easy accessibility for ease of maintenance. Testing the 1/5th scale device in Orkney’s waters gave us valuable information that has allowed us to cost effectively learn from our mistakes, and improve the design to a point where we feel ready to deploy a full-scale device”. The development of the full scale prototype has been greatly progressed as a result of this stage-by-stage testing programme, allowing the team to put their installation methods and technology into practice. Jonathan Meason Lead Structural Engineer “It has always been our approach to come up with smart but simple solutions to the many challenges involved in this industry. There has to be a realistic approach in order to achieve our end goal - a commercially viable product; It’s all about being cost effective.”
In order for the project to succeed, the team at Scotrenewables (Marine Power) Ltd have stressed the importance of a staged development plan. Trevor Walls, Lead Electrical Engineer explained “we felt that moving from a 1/5th scale model straight to a 1MW full-scale prototype was too big a leap. In order to maximise our chances of success, we have opted to move forward in the first instance with a 250KW full-scale prototype. The SR250 will weigh around 80 tonnes and will measure around 30m in length with twin 8m diameter rotors, giving our system a very competitive power to weight ratio”. Having used local fabrication firms for the construction of their 1/5th scale prototype, Scotrenewables will now use Harland & Wolff shipyard to construct the SR250, due to its size. However, local services will be utilised as far as possible once the initial construction of the Tidal Turbine has been completed. It is hoped that this key phase in the project will pave the way for the development of a fully commercial tidal turbine.
Founder Barry Johnston added, “Over the years we have had a number challenges to overcome with this project and I’m delighted that things are progressing well. We are competing with hundreds of other companies from all over the world for funding to allow us to continue our research and development and advance our design and I’m very proud that a Company from Orkney that started in my parent’s garage with a simple idea has been able to get to this stage of development. It has been no easy journey as all of our staff will tell you and it is a great credit to them all as few people have the courage, dedication and ability to innovate in order to make a real difference. We still have a long and challenging road ahead of us but well done to everyone involved in the Company this is a great milestone and I hope for Orkney, in terms of job creation and economic development, that marine renewables is a success in the future”.