Accelerated development of a tidal stream energy industry
Submitting InstitutionUniversity of Manchester
Unit of AssessmentCivil and Construction Engineering
Summary Impact TypeEnvironmental
Research Subject Area(s)
Engineering: Mechanical Engineering, Interdisciplinary Engineering
Summary of the impact
Our research has been key to the development of investor confidence in an
emerging UK tidal stream industry. We have contributed to the development
and validation of commercial and open- source software for tidal stream
system design and our expertise has been instrumental to the successful
delivery of major objectives of two national industry-academia marine
energy projects commissioned by the Energy Technologies Institute (ETI).
Taken together, these outcomes have reduced engineering risks that had
been of concern to potential investors. Investor confidence in tidal
energy has been increased, as highlighted by Alstom's £65m acquisition of
a turbine developer following a key outcome of the ETI ReDAPT project.
The key researchers are:
Professor Peter Stansby (1990-date)
Dr David Apsley, Lecturer (2000-date)
Dr Tim Stallard, Lecturer (2006-date)
Dr Imran Afgan, Lecturer (2010-date)
Our research on tidal stream systems has addressed the development and
validation of computational methods for prediction of the power output
from arrays (farms) of tidal stream turbines  and of the unsteady
loading of tidal stream turbines in realistic tidal flows . This builds
on research into wave energy arrays , CFD methodologies  and the
physics of shallow water flows . The key outcomes have been to:
1) Quantify the influence of hydrodynamic interactions on the loading and
power output of closely spaced groups of horizontal axis tidal stream
rotors. This was enabled by the:
a. Development of unique experimental equipment for friction compensation
systems to represent individual generators at a sufficiently small scale
to study the loading and performance of multiple devices at a laboratory
b. Development of unique experimental equipment for the generation of
both turbulent flow and wakes that are representative of a full-scale
c. Design, conduct and analysis of an experimental study of the loading
and wake of multiple configurations of tidal stream turbines .
2) Develop and validate Computational Fluid Dynamics (CFD) methods with
High Performance Computing for prediction of the time-varying loads on a
tidal stream turbine subject to turbulent flow. This has been achieved by
a. Development and evaluation of a methodology for simulation of fluid
flow past a rotating turbine within close proximity to a stationary
support structure and within a much larger channel flow .
b. Simulation of the characteristics of the turbulent flow measured at a
full-scale tidal stream test-site at the European Marine Energy Centre
(EMEC) accounting for complex tidal turbulence  by use of Synthetic
Eddy Methods previously developed by another group at The University of
c. Evaluation of the influence of CFD methodology, including both
Reynolds Averaged Navier Stokes (RANS) and Large Eddy Simulation (LES)
methods, on the accuracy of load predictions by comparison to scaled
experiments and full-scale data from field trials [1,4].
References to the research
The outcomes of this marine energy research have been published in
leading academic journals, international conferences, PhD theses and
 Stallard, T, Collings, R, Feng, T and Whelan, J., 2013 Interactions
Between Tidal Turbine Wakes: Experimental Study of a Group of 3-Bladed
Rotors. Phil. Trans. Royal Society Part A. 371, 20120159. doi:10.1098/rsta.2012.0159
 Afgan, I, McNaughton, J, Rolfo, S., Apsley, D.D., Stallard, T and
Stansby, P.K., 2013 Turbulent flow and loading on a tidal stream turbine
by LES and RANS. International Journal of Heat and Fluid Flow. (In
press, online 17 Jun 2013) DOI:
 Weller, S.D., Stallard, T.J. and Stansby, P.K., 2010 Experimental
measurements of irregular wave interaction factors in closely spaced
arrays. IET Renewable Power Generation. 4(6), 628-637. DOI: 10.1049/iet-rpg.2009.0192,
 McNaughton, J. 2013 Turbulence modelling in the near field of an
axial flow turbine using Code_Saturne, PhD dissertation University
of Manchester, provided as ETI reviewed technical report for EDF and ETI
Details of the impact
The development of a marine energy industry in the UK, with tidal stream a
major component, is forecast to generate more than 68000 jobs, 20% of
electricity supply and an export market valued at more than £70bn (House
of Commons Select Committee, HC1624, 2012). It has been widely recognised
(UKERC, DECC, ETI) that investors would only make a significant commitment
to tidal stream development after several key engineering developments had
been made including:
i) development and validation of engineering models to predict energy
yield, and hence revenue, from commercial scale farms
ii) demonstration of deployment and operation of a commercial scale
iii) development and validation of engineering tools to enable system
refinement, and hence cost reduction,
iv) increased understanding of the environmental flows at tidal stream
sites pre- and post- deployment.
Pathways to Impact
To ensure rapid exploitation of research findings and methods, our
research has been conducted in close collaboration with leading
engineering companies including EDF, GL-Garrad Hassan, Alstom Ocean Energy
and EON. In particular, Manchester has contributed to the national
projects PerAWaT (Performance Assessment of Wave and Tidal Array Systems)
and ReDAPT (Reliable Data Acquisition Platform For Tidal). Both projects
were commissioned by the Energy Technologies Institute (ETI) and focused
on the engineering topics recognised to be of major concern to potential
investors. Much of the work on these projects has been documented in peer-
reviewed technical reports that are confidential to the ETI and industrial
contributors. This well- managed approach has enabled industry
exploitation of our research in parallel with publication.
Specifically, Manchester researchers have:
- Developed experimental methods that have led to high quality
experimental data on the loading and wakes of tidal turbines in arrays.
The understanding and data from these experiments has "contributed
to the development of GL-Garrad Hassan commercial software tool GH
Tidal Farmer" [C]. This software enables independent
assessment of energy yield, and hence revenue, from tidal stream farms —
a key requirement of energy project investors.
- Developed CFD methods for massively parallel computing to enable the
simulation of turbines and their supporting structures due to complex
tidal flows representative of a real tidal stream test site. These
methods have been implemented in the EDF open-source CFD solver
Code_SATURNE. These numerical tools are "important to the tidal
stream industry since they allow detailed evaluation of design
options prior to field trials." [D]. This has reduced the
dependence of product development on full-scale field trials that
typically cost several million pounds per turbine. These methodologies
are also being used by EDF to analyse different locations and sizes of
offshore wind farms with the approach proving "useful, as most of
our [EDF] previous work has been in CFD of power generation from
nuclear or fossil fuel source or turbo-machinery CFD, which are
quite different areas." [B].
- Developed and conducted CFD simulations and informed field studies of
tidal stream flows to provide data "used to develop and validate
GL-Garrad Hassan commercial software including Tidal Bladed"
[C]. This software is a design tool for tidal turbines based on an
existing code — GH Bladed — for wind turbine design. Validation of such
models specifically for tidal stream turbines has addressed one of the
key engineering risks identified by investors.
- Contributed to expert panels and management committees of national
projects. In 2008 Professor Stansby was invited to join the Severn Tidal
Power Feasibility Study expert panel on behalf of the Royal Academy of
Engineering. This appointment was based on recognised expertise in
coastal hydrodynamics including wave effects, turbulent coastal flows
and marine turbines and complemented the expertise of the five other
panel members. One option under consideration was a tidal fence or row
of tidal stream turbines. Since 2009, Manchester researchers have
contributed to the steering and technical committees of the national
industry-academia projects ReDAPT and PerAWaT commissioned by the Energy
Technologies Institute (ETI). On ReDAPT Manchester researchers are
subcontracted by the project partner EDF. These roles have been
instrumental in ensuring the effective delivery of key project outcomes
focused on development of engineering credibility to reduce investment
Reach and Significance
Manchester's research has increased investor confidence in tidal stream
energy systems. Research outcomes have been "critical to the
development and validation of tidal stream modelling tools"
[A]. This includes commercial software for farm energy yield predictions
and both open-source CFD and commercial software for turbine design.
Increased understanding of array energy yield prediction methods has been
developed that "reduces the investment risk of marine energy project
developers; this is critical to stimulating investment in early farms
to enable the industry to grow." [A]. CFD methods have been
developed and evaluated that have improved understanding of complex tidal
flows and their influence on turbine loading. This CFD capability has
enabled "further de-risking of the tidal turbine design process,
providing increased turbine system robustness and commercial
attractiveness" [A]. High quality data from CFD simulations
and from field trials informed by our research have also been used to
evaluate the GL-Garrad Hassan turbine design software Tidal Bladed.
Taken together, the models that have been developed and evaluated and the
other outcomes of the ETI projects to which we have contributed have
addressed the main engineering risks that had been identified as barriers
to investment in tidal energy. Increased investor confidence has been
demonstrated by the £65m acquisition of Tidal Generation Ltd by Alstom
from Rolls Royce during 2013 [E]. This acquisition was completed following
a key outcome of the ETI ReDAPT project [F].
The findings and process of our research have therefore had a significant
impact on industrial investment in an emerging industry with recognised
value to the UK.
Sources to corroborate the impact
Corroboration letters have been provided by the following to confirm the
contributions of research conducted by the University of Manchester:
[A] Letter from Deputy Chief Engineer, Energy Technologies Institute
confirming the contribution to the projects ReDAPT and PerAWaT and the
significance of specific outcomes of the research to the tidal industry.
[B] Letter from Turbulence and CFD expert research engineers, EDF R&D
confirming the inclusion of the CFD models in Code_Saturne.
[C] Letter from Head of Marine Energy Group, GL Garrad Hassan confirming
the contribution to development and validation of software tools
TidalFarmer and TidalBladed and to the effective delivery of ETI projects.
[D] Letter from ReDAPT programme Manager, Ocean Energy, Alstom confirming
the contribution to the ReDAPT programme and the significance of the CFD
model developments to the tidal stream industry.
In addition the following public documents confirm related facts:
[E] Wave and Tidal Energy in the UK: Conquering Challenges, Generating
Growth, Renewable Energy UK Report, February 2013, (Page 5).
[F] Announcement of Alstom acquisition of Tidal Generation Ltd.