Share reportStructural Materials
This programme investigated if it is possible to make a step change impact in LCOE by constructing typical WEC devices from alternative materials to those traditionally used, such as steel.
Lead contractor
Ove Arup & Partners Ltd
Sub-contractor(s)
Cruz Atcheson Consulting Engineers Lda
British Precast Concrete Federation Ltd
The Concrete Centre Ltd
Mocean Energy Ltd
University of Dundee
Carnegie Clean Energy
K2Management Lda
AWS Ocean Energy Ltd
BAM Nuttall Ltd
Overview
In an offshore environment, reinforced concrete has a lower unit cost and superior durability compared to steel. It is a well understood material and can take advantage of a mature supply chain.
For many WEC types, structural concrete can provide a more effective solution for meeting the mass requirements, using the mass of the structure directly rather than requiring the addition of ballast.
The project has identified a range of structural concrete technologies with the potential for significant impact across a range of WEC types before developing an effective design solution.
Stage 1 of the CREATE project demonstrated the potential benefit of concrete technology in four WEC devices, highlighting the versatility of the material in the sector.
Stage 2 further demonstrated that concrete is a feasible material for application in WECs and can enable significant cost reduction. Design and testing activities mitigated technical risks, with a focus on areas of high localised loading such as tether and mooring connection points, and demonstrated the technical viability of using precast concrete elements in WECs.
The final stage, Stage 3, consolidated the feasibility of structural concrete elements, broadening the range of WEC devices for which concrete-based designs have been developed. A digital decision-making tool, named CONVEX (CONcrete Viability EXplorer), has been developed to assist wave energy device developers identify where incorporating concrete in their technology has the potential to deliver cost reductions. The current capability and capacity of the concrete supply chain in Scotland to support the production of concrete WECs has been mapped. The information acquired from contractors, suppliers, fabrication facilities, and, port and harbour facilities has been collated and presented via a GIS-based interface. The aim of these tools is to prime developers and the supply chain for serial production of floating concrete WEC structures.
Stage 1
May 2018
The objective of Stage 1 of the Concrete as a Technology Enabler (CREATE) project was to identify where concrete has most potential for Wave Energy Converter (WEC) prime mover structures and to demonstrate that the material could enable a step change in the Levelised Cost of Energy (LCoE). The primary advantages of reinforced concrete over steel include a low unit cost (cost per tonne), access to an extensive supply chain and increased durability. Where feasible, equivalent concrete structures have a significantly lower CAPEX. In addition, offshore concrete structures typically have a minimum design life of 50 years and therefore further cost saving can be realised when this design life is utilised. Concrete structures are heavier than steel equivalents for a given strength. However minimising weight is not a primary concern for many WEC devices, particularly those requiring additional ballast. In these cases, structural concrete can present a more efficient solution by using the weight of the structure directly, rather than requiring additional ballast.
Stage 1 of the CREATE project aimed to confirm that concrete is a suitable construction material for WECs and then develop the most promising configurations (WEC type + concrete technology) to a sufficient level to quantify advantages relative to steel. The success of the technology developed by the project can be measured through LCoE, compared to the WES target of £150/MWh, based on a detailed design and manufacturing plan minimising technical risks.
Sea Power Ltd and Wello Oy were additional subcontractors on Stage 1 of the project.
Stage 2
May 2020
Stage 2 of the CREATE project focused on two main key areas:
- The technical viability of precast concrete construction for WEC devices
- Areas of high localised loading
Stage 2 included full scale physical and numerical testing to demonstrate the performance of a critical precast connection on the selected WEC. A manufacturing plan was also developed for Scotland, working with the supply chain. This enabled a details cost analysis to be undertaken.
CREATE Stage 2 demonstrated that the use of precast concrete is predicted to reduce the LCoE by 12% compared to a steel alternative.
Stage 3
March 2021
Stage 3 of the CREATE project is summarised here, with a focus on several key areas:
- What were the aims of the project and what was investigated
- The technology under development
- The WEC designs used as case studies to assess the impact of the CREATE solution
- Performance and manufacturing findings of relevance to the sector
- Details on the freely available CONVEX (CONcrete Viability EXplorer) tool
- Possible routes to commercialisation
- Communications and dissemination
The CONVEX tool is also available to be viewed at: https://convex.ade.arup.com/landing-page
Where to next?
Explore our other programmes, or find out more about how we operate.
About Wave Energy Scotland
Wave Energy Scotland was created by request of the Scottish Government. Discover our purpose, our procurement model and more about our team.