The MPSE SeaAngel Programme: Project 4 Offshore Marine Engineering

Efficient Offshore Wind Programme
What is the Efficient Offshore Wind Programme?
The Efficient Offshore Wind programme (EOW) is a collaborative research and development programme led by Mitsubishi Power Systems Europe with partners SSE, Technip Offshore Wind and Wood Group Renewables. Research and development activity under the programme commenced in April 2010 and is expected to be completed during 2015.
What will it deliver?
The participants have come together to address the technology challenges facing the offshore wind sector. For example the programme will make use of pioneering hydraulic drive technology, developed in the UK, to produce an innovative drive train system designed for application in a high power offshore wind turbine, specifically in the Mitsubishi SeaAngel™ class of wind turbine under development. Many elements of offshore wind farm design will be researched from the perspective of reducing the cost of energy, including; capital cost, reliability, availability, electrical generation and grid compliance, transport and installation, substructure design and installation, operation and maintenance, and health and safety.
Why is it unique?
Technical collaboration between leading members of the value chain at such an early stage is unusual. By collaborating with their combined experience and expertise, the consortium will be better equipped to make more effective design decisions. This will contribute to a better understanding and management of the interfaces and specific challenges in offshore wind power. It will also improve efficiency within all areas of the value chain, from design development to through-life operation and therefore provide a contribution to reducing the overall cost of energy.
How will it benefit the UK?
The UK is the largest offshore wind market in the world and is keen to become a world leader in offshore wind technology. It is intended that the programme will boost confidence to the market and help the industry and Government deliver the vision for offshore wind namely; competitively priced renewable energy and wider economic and environmental benefits. The Programme will enhance the ability of the UK to deliver ‘Round 3’ offshore wind farm developments as well as making a contribution towards the development of the emerging UK offshore wind supply chain. The Programme will help prove the viability of offshore wind and enhance the position of the United Kingdom as a centre of excellence for offshore wind.
What are the specific research areas?
The Efficient Offshore Wind Programme comprises a number of projects:
Hydraulic Digital Displacement® drive train development:
• Artemis Intelligent Power, since 2010 a group company of MPSE, is working with Mitsubishi engineers to create a digitally controlled, highly responsive hydraulic wind turbine transmission. The hydraulic transmission obviates the need to use traditional gearbox and frequency converter. As these two items are often the source of faults in a wind turbine, substituting them is intended to improve reliability, maintainability and ultimately reduce the cost of energy.
• Wind, and particularly offshore wind, is an application area where the legendary robustness of hydraulic transmissions is desirable, however it has to date been rejected for this application primarily due to its low part-load efficiency. Digital Displacement® Technology was created to address this deficiency; the Efficient Offshore Wind Programme provides an exciting opportunity to scale up this technology to the demanding high power and performance levels of offshore wind.
• With its infinitely variable transmission ratio, a Digital Displacement® transmission can be coupled with the varying low-speed wind-turbine rotor to one or more high constant-speed, medium voltage, wound-rotor, synchronous generators. These are the same kind of machines that are used in conventional power stations where they are renowned for their ability to provide network support and for their graceful behaviour during transient network faults.
• Digital Displacement® machines have a fully modular construction which offers the opportunity that if necessary almost all components can be swapped out from within the wind turbine nacelle. This is an important advantage in offshore wind-turbines where it is essential to carry out maintenance without costly support from crane barges or jack-up vessels. The high degree of integration between the electronic and mechanical components of Digital Displacement® machines will provide inbuilt performance and condition monitoring. This is particularly important in offshore wind where a very long design life is sought, service intervals are infrequent and technician access may not be possible for weeks at a time.
Supply chain development and risk mitigation
• In the development of novel technology it is vitally important that the supply chain is engaged at an early stage so that it understands the requirements of the new technology, and is able to deliver the required innovation whilst balancing quality improvement and cost reduction challenges as the project develops and moves into the exploitation stage.
• The consortium partners all share the Government's desire to see the localisation of the supply chain and will work through this programme to engage with the industry. Contributing towards a strong local supply chain is one of the key ways in which the UK can attract the wider economic benefits of offshore wind, whilst also helping to enhance its viability.
• A further element of the project will investigate ways of reducing the number of interfaces between equipment from different suppliers and to increase standardisation across the value chain, through collaboration between the consortium partners at this early stage.
• In the development of new technology it is critical to understand how it can be exploited and brought to the market. A key barrier to the deployment of new technology is its perceived risk in the eyes of the finance and insurance communities. Through early engagement with finance and insurance stakeholders this work package will help to reduce barriers to the deployment of new technology both through better understanding of the associated risks and through the development of risk mitigation strategies that reduce the associated insurance premium.
Optimised substructure design
• The substructure is affixed to the seabed and provides structural support to the wind turbine tower, as well as providing an interface route to the subsea cable connection. It must be capable of handling the loads imparted by the sea and weather conditions and from the wind turbine. In addition it is subject to the harsh marine environment, presenting material erosion and corrosion challenges during operational life.
• The aim of this project is to develop an optimised substructure and transition piece concept for supporting large offshore wind turbines, suitable for low cost bulk manufacture and installation.
• The end design will be adaptable to a range of water depths and sea-bed conditions through the utilisation of bespoke design codes that address both engineering and regulatory requirements, for example end of life decommissioning.
Transport and installation, cable connection
• This project will develop a viable range of concepts for electrical power connection from the wind turbine. This work will include the development of new methodologies for the sea bed installation of cable arrays, cable pull-in techniques, cable protection and connection.
• In addition, this project will develop and document a range of competitive solutions for land-based logistics at the port and water-based logistics for transport and installation of Mitsubishi SeaAngel™ class wind turbines. These will be developed to fulfil Round 3 requirements such as medium volume production, representative distance from shore, wave height and water depth.
Operation and maintenance, health and safety
• To achieve an offshore wind farm design life of over twenty years, a sophisticated approach to operations and maintenance is required. The partners will seek to develop an integrated operations and maintenance strategy by drawing on their combined experience, particularly that derived from the oil and gas sector.
• Within the Efficient Offshore Wind Programme, the operations and maintenance philosophy will be developed at an early stage in the design process. In this way it is intended that design decisions can be made in consideration of maintenance requirements to deliver enhanced operational efficiency.
• The learning outcomes from the offshore oil and gas industry will be built upon in the development of operations and maintenance procedures. Health and safety risk identification, assessment and mitigation shall be carried out to validate all procedures to ensure that safety of operation and maintenance activity is prioritised.
• Optimal component replacement strategies for key components on the offshore wind turbine will be developed with particular consideration to health and safety. These replacement strategies will, where possible be verified at an onshore demonstration site in the UK and if required further refined.