Mid-stage development of the CCell Wave Energy Converter

Lead Research Organisation: University of Bath
Department Name: Mechanical Engineering

Abstract

Recent large-scale laboratory tests of the curved Mark 1 CCell paddle and its control system, conducted with TSB funding
#131499, have demonstrated the predicted four-fold increase in performance to cost ratio compared to other wave energy
devices. Preliminary sea trials of components are ongoing and the technology is now ready for mid-stage development to
build a complete system. This project takes lessons learned from Mark 1 system development and incorporates them into a
Mark 2 Wave Energy Converter (WEC) technology package based on the CCell paddle, its control and its foundation
system.
The project aims to demonstrate cost-effective performance of an array of CCell paddles. This will be achieved through
optimisation of the shape of the curved paddle and Power Take Off (PTO) for a wide range of sea conditions. Intelligent
proactive control algorithms will be developed to maximise power capture in the highly variable conditions that operating
devices will experience. Numerical tools developed and validated as part of the preceeding project will be extended to
study interactions between arrays of CCell paddles. Co-operative PTO control strategies will be developed to optimise
array performance, matching demanded power with generated power and balancing against device loading and
degradation. Prototype systems will be constructed and tested both in laboratory conditions and at sea to validate
concepts.
Successful completion of the project will bring CCell and associated technology to the pre-commercial stage. Economic
viability will be established and the barriers preventing the uptake of competitor technology will be removed.

Planned Impact

National perspective:
The project objectives directly address all three aspects of the energy trilemma:
1) Reducing emissions: The project resides within the Renewable Energy technology challenge area, contributing to the
2020 and 2050 UK emissions targets.
2) Improving security of supply: Wave-energy is a reliable, predictable renewable source with high energy density. The
World Energy Council estimates that wave generated power could deliver 2,000 TWh/year, but this will not happen until the
technology achieves large reductions in £/W. Competitors are deploying ever stronger and larger units in an attempt to
improve the £/W ratio through scale. Even if successful this limits the applicable sites/markets. CCell improves the £/W
ratio through novel design and will be applicable to a wider range of sites/scales. With 15% of the 2020 estimated 85GW
UK requirement to be delivered by renewable sources, this project tackles the security of supply issue.
3) Reducing cost: Research to date suggests our patented curved paddle design will deliver a substantial step change in
performance, delivering twice the power for half the cost of alternative Wave Energy Converters. Secondary cost benefits
include ease of manufacture, installation and an extended structural life. CCell has the potential to allow even small scale
(20-60kW) units to be competitive with conventional energy sources. A pre-commercial system will be delivered by 2018.
International perspective:
Economic: CCell delivers a four-fold improvement in £/W, allowing a small unit to be installed at a price of £2.5/W with an
achievable OPEX cost below £50/MWh. CCell is therefore one of only a few concepts that could make wave energy
economically viable within developed nations. In developing nations access to electricity and water are both prerequisites
to economic growth, and CCell will help to reduce GDP expenditure on these essentials. Currently 80% of the electricity
generated in Pacific and Caribbean countries is sourced from diesel generation, which costs many islands 10% - 30% of
their GDP (~£400M pa), and they are vulnerable to rising fuel costs and global warming. This project addresses a need to
replace remote diesel generation with renewable energy, and a suitable market to target initially is the provision of power
for sea water desalination plants that use reverse osmosis (RO). The demand for freshwater already outstrips supply and
the UN forecast the demand for freshwater will grow by 25% by 2030. Export sales within 4 years will boost UK
manufacturing and the supply chain for RO, hydraulic and electrical generation equipment.
Social: The provision of reliable and independent electricity generation in developing nations is a prerequisite to
improvements in quality of life. By implementing renewable energy generation, there are educational and health benefits to
be realised as well as security of supply, such as the transfer of safe engineering practices and the resultant reduction in
carbon emissions. In addition, the project supports and promotes renewables research at UoB and future undergraduate
and PhD research across the UK
Environmental: We estimate the manufacture and installation of a 20kW CCell WEC with RO unit will be create <10 Tonnes
of CO2, with no CO2 emissions produced during operation. This compares to 62 Tonnes of CO2 per year generated by the
equivalent power diesel generator (excluding engine manufacture).
Commercial Private Sector:
The results of the research will provide developers and regulators with access to high quality validation data against which
they can compare their own results. The research will result in more efficient designs and reduced development time. It will
accelerate the large scale deployment of wave energy devices and the expansion of the emerging wave energy sector, providing employment and associated economic benefits for technology and design code developers and the supply chain.
 
Description Significantly enhanced understanding of Power Take-Off control systems has already been established. Much previous work in the field has been highly theoretical, with little consideration for whether techniques are practically implementable. This project aims, amongst other things, to establish realistic control systems by deploying them on a real Wave Energy Converter at sea. Preliminary simulation and dry-laboratory testing results are very positive.

Several advanced control strategies are under development and have been demonstrated in simulation environments. These have been presented at international conferences and recently published in the Journal of Ocean Engineering. A specialist control PTO system has been designed and constructed for the regeneration of coral reefs using wave energy. This is to be deployed off the coast of Mexico in early 2019.
Exploitation Route The findings ulitmately will be applicable to a wide range of different types of wave energy converter and could help to improve overall capture efficiency and inform structural design. Software tools also under development as part of the project will enable rapid and realistic testing of complete systems including detailed power take-off models.
Sectors Aerospace

Defence and Marine

Energy

 
Description The project proved a range of concepts associated with efficiency, deployment, scaling, power take-off and control. Coastal protection and coral reef regeneration were identified during the project as being potential deployment markets and the technology developed is moving towards commercialisation. Evolutions of the CCell device have been deployed for initial testing and evaluation of the potential of the technology for regenerating coral reefs through electrolysis. This process benefits from the unsteady power supply inherent with wave energy, and furthermore does not require a connection to shore. While this is at a very early stage, the potential impacts will be beneficial to the natural environment, coastal protection and the tourism industry.
First Year Of Impact 2020
Sector Environment,Leisure Activities, including Sports, Recreation and Tourism
Impact Types Cultural

Societal

Economic

 
Description Novel Wave Energy Converters (Round 2)
Amount £252,025 (GBP)
Organisation Wave Energy Scotland 
Sector Private
Country United Kingdom
Start 01/2016 
End 01/2017
 
Description 11th UKACC International Conference on Control (UKACC Control), Belfast 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact International conference on Control. Paper presented as part of a special session on wave energy conversion.
Year(s) Of Engagement Activity 2016
URL https://www.qub.ac.uk/sites/Control2016/
 
Description 20th World Congress of the International-Federation-of-Automatic-Control (IFAC) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Presentation of research at the 20th World Congress of the International-Federation-of-Automatic-Control (IFAC) in Toulouse, France. The purpose was to convey the latest findings to academic peers and industrial end users. Discussion continued following the session and potential new collaborations have been initiated, but not yet formalised.
Year(s) Of Engagement Activity 2017
URL https://www.ifac2017.org/
 
Description Marine Renewable Energy Conference (PRIMaRE) 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Industry/Business
Results and Impact Presentation and poster display to a mixed Academic and Industrial audience. The purpose was to disseminate research findings and discuss future direction and projects.
Year(s) Of Engagement Activity 2014,2015,2016
URL http://www.primare.org/
 
Description Presentation at EWTEC2017 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Presentation at the 12th European Wave and Tidal Energy Conference 2017 in Cork, Ireland. The purpose was to convey the latest research findings to academic peers and industrial end users.
Year(s) Of Engagement Activity 2017
URL http://www.ewtec.org/ewtec-2017/
 
Description University of Bath Design and Project Exhibition 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact This Exhibition presents undergraduate project work to the local academic audience across the University of Bath and to invited external Industrial delegates. Typically over 400 delegates are present. Projects are represented by posters and exhibition stands, with opportunity for discussion across a whole day of activities.
Year(s) Of Engagement Activity 2014,2015,2016
URL https://wiki.bath.ac.uk/display/MechEngDesignExhibition/Home