Lead contractor
Aquamarine Power Ltd
Overview
Aquamarine Power Limited (APL) was responsible for developing the Oyster oscillating wave surge converter (OWSC) technology. APL deployed a full-scale 315kW Oyster 1 at the European Marine Energy Centre (EMEC) test site in August 2009, followed by a second generation machine rated at 800kW, Oyster 800, in August 2011. Experience from these deployments has provided valuable learning to other developers now following in their footsteps. In parallel with device deployments, APL had a strong research focus through a longstanding arrangement with Queen’s University Belfast (QUB). A group of engineers were permanently based at QUB to investigate many novel approaches to scale modelling and capturing energy using an OWSC.
These reports were produced for Wave Energy Scotland (WES) by Aquamarine Power Ltd as a contribution to ‘Project Know-How’. ‘Project Know-How’ is an on-going body of work by WES designed to capture knowledge and key operational experiences from the wave energy sector in Scotland, and in particular the technology development companies based here. This experience is being shared, to avoid others having to go through the same learning exercise.
The Aquamarine Power Limited Know-How reports cover the experiences from the development and installation of the Oyster 1 and Oyster 800 Wave Energy Converters (WECs) at EMEC in Orkney, and include topics such as offshore operations; cathodic protection; supply chain experiences; scaled tank testing and the lessons learnt which lead to maintainability improvements. The Overview document provides a brief synopsis of each of the documents produced by Aquamarine Power, and also includes the high level summaries which act as a ‘sign post’ for the reader.
Subsequently to 'Project Know-How', in late 2015 Aquamarine Power Limited (APL) went into administration and the intellectual property from that company was acquired by WES.
This IP contained data from a range of exploratory small-scale tank testing campaigns which investigated novel features and improving the understanding of performance drivers for an OWSC device type. These tests were completed over the course of the company’s trading history, and the data exists in a raw form without comprehensive supporting reporting and documentation of conclusions. This project documents the findings from the exploratory testing completed by APL, and also records the experience gained in modelling PTO systems for small-scale tank testing.
An addition to the original Project Know-How was then completed, in which WES attempted to draw together these research activities into a coherent and accessible pair of reports, which allows the data to be understood and used productively by developers and researchers. These two reports were prepared on behalf of WES by APL’s former Head of Research and Development (now of Cerebreon Technologies Limited).
Please note that additional reports, documents and data files referenced in the reports available here may not be currently available.
Overview
April 2016
This brief report prepared by Wave Energy Scotland (WES) summarises the original collection of Knowledge Capture documents produced by Aquamarine Power Limited.
The Aquamarine Power Limited Know-How reports cover the experiences from the development and installation of the Oyster 1 and Oyster 800 Wave Energy Converters (WECs) at EMEC in Orkney, and include topics such as offshore operations; cathodic protection; supply chain experiences; scaled tank testing and the lessons learnt which lead to maintainability improvements.
This report provides a brief synopsis of each of the documents produced by Aquamarine Power, and also includes the high level lessons learnt summaries to act as a ‘sign post’ for the reader. A table in Section 6 gives details of the deliverables available from the project.
Share reportOffshore Operations
April 2016
Through the successful execution of two full scale device installations (Oyster 1 and Oyster 800) and consecutive product improvement initiatives, Aquamarine Power gained a wealth of knowledge on numerous aspects of offshore operations including offshore planning, supply chain, vessel capabilities and weather limitations. Offshore operations are a common challenge shared by all developers, and the information presented here will be of value to them, the wider community, and the supply chain.
This report first considers the offshore experience gained from full-scale device installation, supporting the discussion on piling and installation experiences with experiences from Oyster 1 and Oyster 800. The focus then moves methodically through Operations and Maintenance activities, with attention given to vessel characteristics, weather considerations and the planning of maintenance activities, before highlighting experiences and lessons learnt in offshore activities and reporting. The key themes presented are generic to ensure relevance to a wider audience of WEC developers.
Corrosion and Protection
April 2016
Oxygen, biological activities, pollution, temperature, salinity, suspended sediments and velocity are the known major factors which affect the corrosion behaviour of materials submerged in sea water.
In this report Aquamarine Power documented the lessons learnt in design through the use of standard off-the-shelf components and materials, and the effect of material grades and compatibilities in disturbed water environments. Many common themes were identified which could benefit the wider wave community.
Supply Chain
April 2016
Throughout the development of the Oyster Technology, Aquamarine Power suffered from mixed experiences of the supply chain and poor component supply. Many of the components were purchased on the understanding that they were fit for purpose in subsea marine environments, and a number of these were not bespoke and may be considered by other wave developers.
Aquamarine Power often had to choose between expensive ‘oil and gas’ components that were over specified and over-priced, and the other extreme where the costs were more palatable but the product didn’t meet the overall system requirements. This report documents a number of examples of lessons learnt as a result of material incompatibilities, corrosion on subsea wet-mate connectors, and experiences in the use of 316 Stainless Steel and high strength materials. The problems caused by these components led to significant cost and programme setbacks at Aquamarine Power, and the lessons learned will be pertinent to all other wave technology developers, particularly those making the transition to wet-testing.
Tank Testing of WECs
April 2016
In the current stage of the wave energy industry, experimental wave tank testing forms an integral part of WEC device development. The knowledge and expertise acquired by Aquamarine Power was developed in partnership with Queen’s University Belfast (QUB), with whom the company had a long standing relationship, and this report documents the experiences and lessons gained from over 10 years of wave tank testing in the development of Oyster.
Experiences cover a range of activities through the whole design process, from early concept development through to full-scale model validation. The common themes presented include tank calibration, performance and load testing, installation and decommissioning testing, correlations between a scaled model and full-scale prototype, and the development of new concepts. In addition to the lessons learnt by Aquamarine Power, the report also gives a critical review and assessment of the existing tank testing standards documents.
Maintainability
April 2016
The experiences and lessons gained on the Oyster 1 project led Aquamarine Power to make some fundamental changes to the design philosophy to improve access and maintenance for Oyster 800. This package of work highlights the lessons learnt on the Oyster 1 project, and documents how these areas were improved for Oyster 800. The report also highlights where the changes made were effective and where they could be improved further.
The maintenance philosophies are considered, first examining the case study of the Oyster 1 experience and including a review of access issues to WEC components and activities such as cylinder exchange. General observations on the influence of the equipment, work vessel, and offshore personnel/dive teams are described, which are intentionally high level to be relevant to all the needs of all developers. The modularity and inherent maintenance features implemented for Oyster 800 are covered in detail, such as the cylinder and accumulator modules, while the poor reliability of the non-modular components and the modifications made post-installation to improve this are also described.
Exploratory WEC Research
August 2017
Nine key research topics, which relate to the exploratory WEC research completed by APL for flap-type Oscillating Wave Surge Converter (OWSC) devices, have been identified and are summarised and independently presented within this report which has been prepared on behalf of WES by APL’s former head of R&D (now of Cerebreon Technologies Limited).
In each case, a detailed narrative is provided which explains: the rationale behind the research investigation, qualitative and quantitative conclusions, references to supporting and publicly available information, and the reasoning behind any decisions made by the company following on from the research. The information is being shared now for the benefit to the wider wave energy sector, and to provide additional information to technology developers.
While the numerical results of the APL research may be unique based on their particular version of the OWSC technology, others should find this information of use.
Scaled PTO Damper Options
March 2018
This report presents the details of a range of Power Take-Off (PTO) dampers used for small-scale experimental WEC testing, considering design and sizing limitations, through to experiences from testing and trialling.
The dampers discussed are those investigated, designed and used by APL and their research partners Queens University Belfast (QUB) in the development of Oscillating Wave Surge Converter (OWSC) devices. Ten different systems are presented spanning scales between 1:40 and 1:20, and a range of different damping mechanisms including: friction, hydraulic actuation, and electric/magnetic actuation. A detailed description and examples of the damping characteristics each system delivers are presented, along with its used historical use by APL/QUB. The advantages and disadvantages of each system are also discussed, and a critical evaluation against key assessment metrics is presented in an attempt to identify a preferred system for future WEC development research.
The learning presented here will be valuable for early stage developers, within the WES programme and beyond, who need to consider the design of smaller-scale physical models for performance and survivability testing.