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PERPETUUS TIDAL ENERGY
CENTRE LTD PTEC Developer Consultation
Date – October 2013
ITP/REF – UKP 1191
PTEC Developer Consultation Report
UKP1191 i October 2013
This project has been co-funded by ERDF under the INTERREG IVB NWE programme. The report
reflects the author’s views and the Programme Authorities are not liable for any use that may be made
of the information contained therein.
Perpetuus Tidal Energy Centre Ltd
IT Power reference: UKP1191
October 2013
Contractor:
IT Power
St. Brandon’s House
29 Great George Street
Bristol, BS1 5QT, UK
Tel: +44 117 214 0510
Fax: +44 117 214 0511
E-mail: [email protected]
www.itpower.co.uk
Document control
File path & name I:\Data\0WorkITP\0Projects\1191 PTEC Phase 1 Delivery FEED &
EIA\2 Work\Developer consultation\
Author J. Hussey, M. Leybourne
Project Manager J. Hussey
Approved
Date October 2013
Distribution level Final
mailto:[email protected]://www.itpower.co.uk/
PTEC Developer Consultation Report
UKP1191 ii October 2013
TABLE OF CONTENTS
1 INTRODUCTION .............................................................................. 1
1.1 PTEC ................................................................................. 1
2 SCOPE AND METHODOLOGY ............................................................... 1
2.1 Scope ................................................................................ 1
2.2 Key Objectives ..................................................................... 1
2.3 Methodology ........................................................................ 2
2.4 Parameters for Discussion ........................................................ 2
3 DEVELOPERS ................................................................................. 3
3.1 Turbine Neutral Platforms ........................................................ 4
3.2 Floating Devices (Axial Flow) ..................................................... 5
3.3 Axial Flow (Bottom Mounted) .................................................... 5
3.4 Cross Flow (Bottom Mounted) .................................................... 6
3.5 Other ................................................................................. 7
4 CONSULTATION RESPONSES ............................................................... 8
4.1 Interest in PTEC and Timing ...................................................... 8
4.2 Site Design / Layout ............................................................... 9
4.3 Device Design / Configuration ................................................... 9
4.4 Foundations / Moorings ........................................................... 10
4.5 Electrical Infrastructure .......................................................... 11
4.5.1 Ratings and Voltage ....................................................... 11
4.5.2 Power Electronics ......................................................... 11
4.5.3 Isolation ..................................................................... 11
4.5.4 Communications ........................................................... 11
4.5.5 Low voltage / Back-up Electricity Supply .............................. 12
4.6 Installation Approach .............................................................. 12
4.6.1 Vessels ...................................................................... 12
4.6.2 Installation Port Requirements .......................................... 12
4.7 Operation and Maintenance Considerations .................................... 12
4.8 Other ................................................................................. 13
5 FUTURE MARKET GROWTH PREDICTIONS ................................................ 13
5.1 First Arrays .......................................................................... 13
5.2 Larger ‘Commercial’ Projects .................................................... 14
6 CONSIDERATIONS FOR PTEC INFRASTRUCTURE AND ROCHDALE ENVELOPE ......... 15
6.1 Size and number of berths / cables ............................................. 16
6.2 Voltages ............................................................................. 16
6.3 Progress towards Design Freeze ................................................. 17
APPENDIX A: DEVELOPER QUESTIONNAIRE ....................................................... 0
7 INTRODUCTION .............................................................................. 1
7.1 Scope ................................................................................ 1
7.2 Key Objectives ..................................................................... 1
8 QUESTIONNAIRE ............................................................................. 2
PTEC Developer Consultation Report
UKP1191 1 October 2013
1 INTRODUCTION
This document summarises the results of the developer consultation carried out as part of
the FEED work for the PTEC project.
The developer consultation will be used to determine the technical requirements and level
of interest in the site by the leading tidal technologies. Also, importantly the consultation
will be used to determine the preliminary site layout, outline Rochdale Envelope, and input
into the EIA, infrastructure requirements and project design statement.
Thirty nine of the most advanced or promising tidal technology developers were contacted
as part of this exercise, these comprise companies who are already in discussions with PTEC
about potential deployments as well as other companies identified as potential customers.
The full list of developers approached can be found in Section 3.
A copy of the questionnaire used can be found attached as Appendix A. The answers to these
questions are summarised, analysed and discussed anonymously in Section 4.
1.1 PTEC
The Perpetuus Tidal Energy Centre (PTEC) is a managed demonstration facility for tidal
energy developers; suitable for the deployment of up to full scale single units and small
arrays from prototype to pre-commercial demonstrators. The offshore facility will be a
20MW demonstration site located approximately 2.5km to the south of St. Catherine’s Point,
and will include grid connection via subsea cables as well as navigation aids and monitoring
equipment.
2 SCOPE AND METHODOLOGY
2.1 Scope
The purpose of the consultation was to obtain a coherent list of requirements from
technology developers that can inform the FEED study for the design of the electrical system
and integrate effectively with the consenting process. The outputs from this consultation
will be captured in the preliminary site layout, outline Rochdale Envelope, and input into
the EIA, infrastructure requirements and project design statement.
IT Power asked 40 developers, in high level terms, about their potential timescales for
deployment, as well as a series of technical questions relating to their technology.
IT Power did not discuss any commercial matters relating to the developers or PTEC.
2.2 Key Objectives
The four main objectives for the developer consultation were as follows:
1. Obtain information to define requirements for the FEED Study, comprising:
Technical data relating to the device.
Infrastructure requirements.
Deployment plans and requirements.
O&M plans and requirements.
Data to define the Rochdale Envelope and project design statement.
PTEC Developer Consultation Report
UKP1191 2 October 2013
2. Understand the approximate deployment timescales expected by the developers.
3. Understand the ideal services that they would require from PTEC.
4. Understand the ideal port and onshore support infrastructure requirements on the
Isle of Wight.
2.3 Methodology
A document detailing the developers to be contacted, information about each, and the
approach to be used (who and how contacted) was produced for approval by PTEC.
A questionnaire was developed, based on the information described in section 2.4. This
questionnaire was filled in from the result of face-to-face meetings or during phone
conversations where possible, and was sent out by email where this was not the case. The
contents of the questionnaire were used to loosely guide conversations with the developers
in order to capture all of the necessary information and was agreed by PTEC before it was
issued. The questionnaire is attached as Appendix B.
In addition, an information document providing an introduction to PTEC was produced which
outlined the work that has been carried out to date and general information about the
project including key headline data such as bathymetry and typical flow velocities. This was
sent to the selected developers to help sell the concept of PTEC, show how well advanced
the project is and to raise their awareness and interest in PTEC. This document was also
agreed by PTEC before it was issued.
2.4 Parameters for Discussion
IT Power discussed the following parameters with the developers:
Site design
Layout of berths within PTEC
Potential layout of devices and infrastructure within the berths
Connection to transmission infrastructure
Number of devices, if deployed in an array
Timing
Approximately when will the device(s) be deployed
What would be the intended length of deployment
Device design
Device configuration (axial/transverse/other)
Surface piercing/floating/sub surface
Foundation/mooring type and design (GBS/piled)
Footprint of deployment
Blade number, dimensions and rotation speed
Electrical output – rated capacity and voltage
Control (specifically location of converters), communications and electrical
isolation methodology
Installation approach
Duration and seasonality of offshore installation activity
PTEC Developer Consultation Report
UKP1191 3 October 2013
Installation equipment and vessels to be used
Methodology
Port requirements
Hard standings and road access
Operational and maintenance considerations
Personnel and vessels required
Frequency of scheduled maintenance interventions
Frequency and type of scheduled surveys
Unscheduled maintenance
Back-up electricity supply requirement
Port requirements
Decommissioning
Approach to decommissioning
Other onshore support infrastructure requirements
Ideal services that a developer would expect PTEC to provide
Other
Personnel involved during deployment
Health & safety considerations
Key results of any prior EIA studies
Willingness for sharing of data (environmental monitoring)
The answers to these questions and all additional comments were tabulated for ease of
collation and comparison.
These are summarised and discussed in Section 4; to ensure confidentiality, this is done
without reference to the developers themselves or the source of any particular response.
Where developers were uncertain about their approach or the detail required, IT Power has
endeavoured to fill in the data as accurately as possible, based on our knowledge of similar
systems. Where this has been done, it is noted in the report.
3 DEVELOPERS
The following 40 tidal technology developers were contacted during this work. These
represent advanced developers whose further development timescales are likely to fit those
of PTEC, as well as promising early stage technologies, and those who have expressed an
interest in the site.
For the purposes of this report, the developers have been categorised into the flowing:
Turbine Neutral Platforms
Floating Devices (Axial Flow)
Axial Flow (Bottom Mounted)
Cross Flow (Bottom Mounted)
Other
Comments on the applicability of these technologies and their level of interest in the site
are summarised in Sections 3.1 to 3.5.
PTEC Developer Consultation Report
UKP1191 4 October 2013
1. Andritz Hydro Hammerfest
2. Aquascientific
3. Atlantis Resources Corporation
4. BioPower Systems
5. Blue Energy Canada
6. Bluewater Energy Services B.V.
7. Blue Tidal Energy
8. Clean Current Power Systems
9. Ecomerit Technologies - Aquantis
10. ETI
11. Flumill
12. Green-Tide Turbines
13. Hyundai Heavy Industries
14. Kawasaki Heavy Industries
15. Kepler Energy
16. Marine Current Turbines (MCT)
17. Minesto
18. Nautricity Ltd
19. Nova Innovation Ltd
20. Ocean Flow Energy
21. Ocean Renewable Power Co. LLC
22. OpenHydro
23. Sabella SAS
24. Scotrenewables
25. SeaPower Gen Ltd
26. SMD Hydrovision
27. SME
28. Straum - Hydra Tidal
29. Sub Sea Turbines
30. Swan Turbines
31. Tidal Energy Limited
32. Tidal Generation Ltd (TGL)
33. Tidal Sails AS
34. Tidal Stream Limited
35. Tocardo BV
36. Toshiba
37. Verdant Power
38. Verderg
39. Voith Hydro
40. QED Naval
3.1 Turbine Neutral Platforms
Turbine neutral platforms provide a means to mount several turbines and associated
electrical systems on a common platform. The platforms are designed to accept different
types of turbines from different developers. There are a wide variety of approaches used
for the platform, from surface piercing, floating to sub-surface bottom mounted. Therefore
different anchoring methods are used, with most opting for either piles or gravity anchors.
Turbine neutral platforms are well suited to the PTEC site given the water depths and berth
sizes. These platforms could also provide the opportunity to demonstrate several different
turbines without the need to completely change the platform itself over the lifetime of the
project.
The turbine neutral platforms consulted as per of this exercise were:
Developer Response Received
Bluewater Energy Services B.V. Responded
SME Responded
Tidal Stream Ltd Responded
QED Naval Responded
PTEC Developer Consultation Report
UKP1191 5 October 2013
3.2 Floating Devices (Axial Flow)
Floating devices are intended to exploit the faster flow speeds encountered near the
surface; the designs can reduce the foundation infrastructure required, but require
integrated mooring and anchoring solutions. The anchors have to be selected based on the
seabed conditions at the site. There is often some surface piercing element to the design.
The deeper water at PTEC, when compared to many good tidal sites, makes it ideal for
floating technology. Their deployment at the site may however have implications for
consenting from a navigation and visual impact point of view.
Floating devices consulted as per of this exercise were:
Developer Response Received
Ecomerit Responded
Nautricity No response
Ocean Flow Energy Responded
Scotrenewables Responded
SMD Responded
Straum As No response
3.3 Axial Flow (Bottom Mounted)
These devices are often referred to as horizontal axis tidal turbines (HATTs).They are similar
to technologies used in wind energy. Generally, axial flow turbines are composed of a
number of blades which are connected to a hub which rotates about a horizontal axis. Axial-
flow turbines extract energy from moving water in much the same way as wind turbines
extract energy from moving air. The turbine is aligned so that it points into the flow with
the rotational axis parallel to the flow. The turbine rotor may be housed within ducts to
create secondary flow effects by concentrating the flow and altering the flow velocity of
the water passing through the turbine to focus the extractable energy.
There are also various approaches to control - rotors with fixed pitch (stall controlled) and
variable pitch turbine blades are both under development in the industry.
Axial flow turbines are the most well developed type of tidal energy converter technology,
with a number of device concepts at a pre-commercial stage.
These developers use monopoles, tripods, quadrapods, or a similar type of jacket / frame
to mount their turbines and are held in place using either piles or weights.
Most current 1MW, bottom mounted turbines are looking for water depths of 40 to 50m,
although a few are looking to deploy larger machines in even deeper water. The range of
water depths at the site provide a number of locations for such deployments. A number of
these developers however are concentrating on smaller machines, and the lack of areas
shallower than 35m at the site could prove difficult for these.
PTEC Developer Consultation Report
UKP1191 6 October 2013
Axial flow, bottom mounted turbines consulted as per of this exercise were:
Developer Response Received
AndritzHydro Hammerfest Responded
Atlantis Resources Corporation Responded
Clean Current Responded
Green-Tide No response
Hyundai Heavy Industries No response
Kawasaki Heavy Industries No response
MCT (Siemens) Responded
Nova Innovation Responded
OpenHydro Responded
Sabella SAS No response
Sub Sea Turbines No response
Swan Turbines No response
TGL (Alstom) Responded
Tidal Energy Limited Responded
Tocardo Responded
Toshiba No response
Verdant Isles Responded
3.4 Cross Flow (Bottom Mounted)
These devices have a cross-flow design with the blades rotating about an axis perpendicular
to the direction of the tidal flow mounted either vertically or horizontally. Cross-flow
turbines have not reached the same level of development as axial flow turbines, with no
full scale, pre-commercial devices deployed. A cross-flow turbine rotates in one direction
making it suitable for bidirectional tidal flows. As with axial-flow turbines, some designs
also make use of ducts to enhance flow. Devices typically have a lower hydrodynamic
performance than axial-flow turbines, but have other benefits such as rectangular swept
area, better suited to shallow tidal flows, and scalability (up to multi-MW devices).
Straight bladed configurations are often referred to as Darrieus turbines in recognition of
the original patent holder Georges Jean Marie Darrieus. A helical bladed configuration of
the Darrieus turbine (often referred to as a Gorlov turbine after their original patent holder
- Alexandar m. Gorlov) can improve consistency of shaft torque output as well as improving
rotor self-starting characteristics.
PTEC Developer Consultation Report
UKP1191 7 October 2013
As with the bottom mounted axial flow devices, the developers use monopoles, tripods,
quadrapods, or a similar type of jacket / frame to mount their turbines and are held in
place using either piles or weights.
A key advantage of cross flow turbines is the ability to deploy them in shallower water than
a similarly rated axial flow machine. As such, most developers of this technology are
targeting shallow water regions (less than 30m), the lack shallow water at PTEC could be a
problem for many of these.
Cross flow, bottom mounted turbines consulted as per of this exercise were:
Developer Response Received
Ocean Renewable Power Company Responded
Blue Energy Canada Responded
Blue Tidal Energy Responded
SeaPower Gen Responded
Kepler Energy Responded
3.5 Other
This category covers all other technologies that do not fit into the categories above.
Operating principals include, oscillating or ‘traversing’ hydrofoils, venturies, Archimedes
screws and novel applications of ‘standard’ turbine types.
The foundation systems envisaged for these technologies are broadly similar to those
employed by the classifications above.
Developer consulted as per of this exercise were:
Developer Response Received
Minesto Responded
Aquascientific No response
BioPower Systems No response
Flumill Responded
Tidal Sails No response
Verderg Responded
ETI Responded
PTEC Developer Consultation Report
UKP1191 8 October 2013
4 CONSULTATION RESPONSES
IT Power obtained responses from 27 of the 40 developers consulted; the remainder declined
to do so or did not respond to approaches. Where known, IT Power have filled in details for
those who did not respond.
16 of the developers consulted have already constructed and deployed a full or near-
full scale prototype machine.
26 have tested a scale turbine in realistic conditions.
14 are still at the concept or preliminary design stage.
A summary of these developer’s responses is provided in the reminder of this section. To
ensure confidentiality, this is done without reference to the developers themselves or the
source of any particular response.
4.1 Interest in PTEC and Timing
Interest shown in PTEC by respondents was as follows:
18 developers stated they were interested in deploying technology at PTEC.
11 were very keen and / or are already in discussions with PTEC themselves about
such deployments.
7 saw the site as a possible back-up to their existing strategies if they didn’t go
according to plan.
7 developers were not interested in the site because they were only looking for
commercial sites or they had no intention of building projects.
Only 1 developer ruled out PTEC on the grounds of the electrical system. This was a
developer that required a single cable to shore for each turbine deployed.
Most respondents said they would be looking to deploy their first array project between
2016 and 2018. This was the case even for those who had not yet built their first full-scale
prototype; IT Power does not believe these timescales are realistic for these early stage
developers.
Table 1 below shows possible deployment scenarios for the site, based on those who have
expressed an interest in the site and have indicated a size project they would like to deploy.
The ‘possible projects’ column includes those who see PTEC as a back-up as well as early
stage developers with expressed very ambitious plans. ‘Realistic Projects’ only includes
advanced developers who have expressed a real interest or those who have the potential to
meet their stated timescales.
It is important to note that for the vast majority of devices, deployment is contingent on
funding to build the turbines for the site. In several cases, funding is still required to design
or prove their technology.
PTEC Developer Consultation Report
UKP1191 9 October 2013
Table 1: Possible Deployment Scenarios for PTEC
Year Possible Projects (MWs) deployed Realistic Projects (MWs) deployed
2016 10 Projects, 23.575 MW 6 Projects, 12.475 MW
2017 4 Projects, 18.6 MW 3 Projects, 15 MW
2018 5 Projects, 10 MW 2 Projects, 6 MW
2019 3 Projects, 9 MW 1 Project, 4 MW
2020 1 Project, 3 MW 1 Project, 3 MW
Most of the developers questioned were looking for a lease term of at least 10 years, but
ideally as long as possible.
4.2 Site Design / Layout
Only 4 developers were interested in deploying small / single machines at the site, although
this is to some extent driven by how the site has been presented and the most advanced
developers questioned.
The developers of small devices had turbines rated between 30kW and 200kW. In some cases
this was due to a deliberately slow scaling up process, others see a substantial market for
small turbines, so do not intend at this stage to scale up their turbines. IT Power is aware
of at least 12 developers looking to exploit this market. There is therefore scope to have a
1MW berth available for a nursery site within the site.
Sizes of berths that developers were interested in were as follows:
5 wanted a berth of 6MW or more
3 wanted a berth between 3.1MW and 5.9MW
5 Wanted a berth between 1.1MW and 3MW
5 wanted a berth up to 1MW
8 developers required deep water (greater than 35 - 40m), whilst 11 required shallow areas
(less than 30m) at the northern boundary of the site.
4.3 Device Design / Configuration
This element of design was understandably the most well considered, with developers
having put a lot of time and effort into the design and layout of their rotors and power take
off system.
PTEC Developer Consultation Report
UKP1191 10 October 2013
The majority of developers consulted were using axial flow turbines. These were also
generally the most advanced:
24 of the developers consulted were developing axial flow turbines.
5 were developing cross flow turbines.
6 were exploiting some other power take off configuration.
4 were developing turbine neutral platforms.
8 developers have or are intending to use large rotors of 16m diameter or more. All but 6
had rotational speeds of 15rpm or less; these 6 had rotational speeds above25rpm. The
majority (18) were 3 bladed.
9 developers employed pitch control of the rotors.
17 developers had a design employing more than one rotor on their structure; this includes
the developers of turbine neutral platforms
11 of the 39 developers approached would intend to deploy surface piercing technology at
the site.
4.4 Foundations / Moorings
Only 17 of the 39 developers consulted had a definite foundation / anchor design. 9
developers indicated that foundation choice was site specific, this was particularly the case
with the floating systems. Most of the early stage developers had not yet fixed this element
of their design.
A few developers are also concentrating on the turbine element only, and will be relying on
others to supply mounting (foundation) systems such as the developers of ‘turbine neutral
platforms’
The breakdown of foundation / mooring concepts for those with a definite solution was as
follows:
Monopile: 7 developers
Multi-pile (pin piles) : 16 developers
Tripod - 8 developers
Qudrapod - 1 developer
Other - 7 developers (includes pinned anchors for mooring lines of floating
systems)
Gravity base: 7 developers
It should be noted that there is some overlap between these categories, i.e. a few
developers make use of a tripod gravity base (tripod support structure secured with ballast
weights).
The footprint of deployment varied significantly between the developers, with single,
bottom mounted turbines requiring a small seabed area per device (
PTEC Developer Consultation Report
UKP1191 11 October 2013
4.5 Electrical Infrastructure
4.5.1 Ratings and Voltage
Most machines were rated at 1MW or more. 11 developers were intending to develop
machines rated at over 2MW, the majority of these will use multiple turbines on a single
platform to achieve this. Only 3 developers are intending to build individual turbines rated
2MW or more.
Most developers did not have a definite export voltage in mind, this was largely because
most had not yet reached a point where they had to specifically define this. Others were
currently exporting at a relatively low voltage, and intended to scale this with device size.
Most of the advanced developers (11) were currently exporting at 6.6kV. This is largely
driven by the system voltage at EMEC, which is 6.6kV, and to some degree by the cost and
availability of subsea connectors certified for higher voltages. Many of the advanced
developers stated that they intended to export at 11kV, in the long run, but were not yet
at that stage.
13 developers said they were able to export at either 11kV or 6.6kV (possibly even 33kV),
depending on the requirements of the PTEC infrastructure, through appropriate transformer
choice.
Only 3 developers were intending to export at their generator voltage (with no on-board
transformer), and were therefore looking for voltages of less than 6.6kV.
The majority of developers would connect to the PTEC cable infrastructure by a dry mate
connection, 7 device developers preferred a wet mate connection.
4.5.2 Power Electronics
Most developers intend to incorporate converters and power electronics into the ‘nacelle’
of their machine. 6 were planning converters onshore or in their own sub-sea hub. 13 had
not considered this element in detail and were therefore unsure.
4.5.3 Isolation
Most developers (14) were planning a circuit breaker on each individual machine, although
all developers expected their cable / connection to be isolated for connection and removal
of machines. The remainder are unsure or did not respond. Only 3 developers are not
intending a circuit breaker on-board their machine.
4.5.4 Communications
All but 2 of the developers questioned intended to use fibre optic cables for communication
with their device. Most of those who had previously deployed a large scale machine (at
EMEC) also intended to use Wi-Fi or a radio link as a backup.
The 2 developers who expressed a preference not to use fibre optics preferred to use a
copper data cable due to the expense of fibre optic converters, slip rings etc.
PTEC Developer Consultation Report
UKP1191 12 October 2013
4.5.5 Low voltage / Back-up Electricity Supply
10 developers said they required a low voltage, auxiliary / backup electricity supply. 6
stated that this was a ‘nice to have’ but could be obtained from their own on-board
transformer or batteries if necessary. Few developers consulted were able to give an
indication of what this supply should be; responses ranged from 1kV to 20kW.
4.6 Installation Approach
Installation strategies varied widely depending on the foundation / mooring approach of the
developer.
7 developers intend to install foundations, then lower, ballast or pull the nacelles /
turbines down onto the foundation.
9 developers intend to use floating systems that remain on the surface attached to
pre-installed anchors and mooring lines.
11 developers plan to install their foundation and turbine as a complete unit.
4.6.1 Vessels
The most common installation vessel required was a DP vessel; 19 developers required one
for at least part of their installation. 8 developers required multicat or tug boats, although
most of these required a DP vessel (or moored barge) for their foundation or anchor
installation. Only 1 developer intended to use a bespoke installation vessel.
This drove sea-state restrictions, which was generally a maximum of 1.5m Hs. Only one
developer believed they may be able to install their technology in larger sea-states than
this.
4.6.2 Installation Port Requirements
Most developers who have considered this aspect required a laydown area of at least 60m2,
a quay with hardstandings to lift at least 200t (up to 400t) and a draft suitable for the DP
installation vessel used (approximately 8m).
6 developers intend to mobilise their machines directly from the fabrication yard, so did
not see an installation port as a requirement.
The majority of developers consulted had not considered this factor in enough detail to
meaningfully answer.
4.7 Operation and Maintenance Considerations
O&M strategies also varied considerably, with developers falling into one of two camps.
Those with an intervention period of several years (generally between 2 and 5) – 8
developers.
Those who intend to access their machines for maintenance planned and unplanned)
many times during the years – 8 developers.
The remainder had not considered this aspect in detail or did not respond.
PTEC Developer Consultation Report
UKP1191 13 October 2013
The first group, consisted largely of those advanced developers with very simple technology,
the majority of their complex systems onshore and with more complex access requirements.
There were also a few early stage developers in this category, with possibly unrealistic
expectations around reliability of systems and components.
Access to machines for maintenance was planned in a manner broadly similar to their
installation process.
7 developers were intending to carry out all but the most major of maintenance
activities on-board machines whilst on site.
22 intend to remove machines to an O&M port to carry out this work.
4.8 Other
Additional services, infrastructure or requirements from developers were as follows:
Support for consenting. Reduction of regulatory burden.
Relationships with universities (or similar) for pre and post construction monitoring.
Agreed monitoring strategy across the site / all projects, supplied by PTEC as part
of services.
Metocean conditions - particularly tidal flow monitoring, but also realtime wave
monitoring and forecasting for the floating devices.
Metering of electrical output from devices / arrays.
A range of suitable, general vessels and equipment available, including experienced
crews with knowledge of the area, for all developers to hire as and when required.
Office space.
A site manager that can co-ordinate work and emergency plans across the site.
Engineering design services available.
Third party performance assessments, for standards & certification.
Nearly all developers indicated that they were in principle happy to share monitoring data.
5 FUTURE MARKET GROWTH PREDICTIONS
To date, the UK Government has not set an official target for marine energy but the latest
roadmaps and studies have indicated a potential to install anywhere from 100MW to 400MW
of tidal energy by 2020.
5.1 First Arrays
The industry at present is in a strong position and is poised to begin deploying the first small
commercial arrays. These are intended to prove that multiple devices can operate together
in the same location and supply power to the grid at a rate close to utility scale. The
successful demonstration of these first arrays will be critical in the progression of the
industry and will result in larger, fully commercial arrays being deployed with a significant
increase in the total installed capacity. Based on the current state of the industry and
knowledge of the activities of technology and project developers, IT Power believes that it
is likely to be at least 2 – 3 years before these first, small arrays are installed and grid
connected in the UK.
PTEC Developer Consultation Report
UKP1191 14 October 2013
Demonstration sites like PTEC that allow such array projects to be built without each
developer having to bear the full cost of the electrical infrastructure and development risk
will have a key role to play in these early projects.
During the demonstration and proving of first generation tidal devices, new second
generation technologies are starting to be developed with the aim of reducing costs and
increasing output. This will build on the learning achieved through the operational
experience gained from the first generation turbines. Such advances will see larger turbines,
multiple units being deployed on a common structure, improved deployment and recovery
methods and lower installation costs. This will allow developers to access a large proportion
of the UK’s tidal stream resource with technologies that are able to be installed at deep
water, high velocity and hostile sites. Third generation machines are expected to target at
low flow sites; very deep water or very shallow water. This will open up a huge area of
resource, often ignored in estimates of exploitable potential. Exploitation of these sites has
even more potential outside of the UK.
The Crown estate has so far issued 26 leases or Agreements for Lease to tidal projects,
totalling over 1.3GW of potential capacity. 16 of these are for small array projects of 10MW
or less (totally around 50MW). Each of these projects represents a credible developer and
thus a potential customer for PTEC. Many of these projects will not get constructed for
various financial and consenting reasons, making PTEC an even stronger prospect for these
developers.
5.2 Larger ‘Commercial’ Projects
Following these initial arrays, developers will seek to optimise the energy yield from each
unit and the total combined array output. With the learning acquired from the first arrays
and the installation of second generation arrays, the improved device technology should
demonstrate cost reductions to increase the commercial competitiveness of tidal energy
against other forms of renewable generators. The magnitude of public revenue support for
tidal energy is expected to reduce over the next decades as the technologies mature and
therefore require less financial support. DECC aims for the revenue support to reach parity
with offshore wind by approximately 2027, although this is likely to be flexible, based upon
the progress of the industry. It is, however, imperative that the cost of energy decreases
rapidly in order for the tidal industry to become cost competitive with offshore wind and
other large scale, renewable generating technologies before 2030.
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Figure 1: IT Power’s predictions for the deployment of tidal energy converters,
including capital and revenue support mechanisms.
(Adapted from the Marine Energy Action Plan Report, DECC 2009
The roadmaps that have been generated have been useful in guiding Governmental policies
and conveying the needs and requirements of the industry however, the predicted
timescales and magnitudes of the deployment of marine energy have all been optimistic. IT
Power’s timescale predictions for the deployment of tidal energy are shown in Figure 1 are
based on the company’s experience in the industry and involvement with many tidal
development projects. Whilst these may seem pessimistic, in terms of timescales, than
many of the roadmap predictions made over the recent years, they represent a more
realistic timescale over which significant engineering challenges will be overcome and the
large scale deployment of TECs at a utility level will be made.
6 CONSIDERATIONS FOR PTEC INFRASTRUCTURE AND ROCHDALE ENVELOPE
The responses obtained during this consultation prove that PTEC will have to be very flexible
in order to accommodate as many developers as possible, and the Rochdale Envelope would
need to be very broad. The difficulty and expense of incorporating all technologies
consulted as part of this work would not be worthwhile. The suggested ‘extremes’ that
could be covered by the Rochdale Envelope are shown in Table 2 below. This will be further
refined with appropriate sample technologies to represent these extremes selected in
collaboration with PTEC and the EIA team. As part of the Rochdale envelope and EIA process,
consideration will also need to be given to exclusion/safety zones and process for defining
and implementing these if required.
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Table 2: Considerations for Rochdale Envelope
Element ‘Worst case’ Possibility
Number of machines (complete units,
which could comprise multiple rotors) Up to 30
Device configurations Axial flow, cross flow, ducted
Rotors
Up to 25m rotor diameter
Up to 70 individual rotors
Up to 60rpm
Location Bottom mounted, mid-water column,
floating / surface piercing
Foundations (structure) Monopile, tripod, frame up to (30m x
30m)
Moorings, anchors (securing system) Monopile, pinpiles, gravity base
Up to 90 individual piles installed
Cables
Up to 6 separate export cables
Up to 30 separate ‘inter-array’
(turbine) cables
With regards to the infrastructure supplied by PTEC, the following should be considered:
6.1 Size and number of berths / cables
5 developers indicated they wanted a berth of at least 6MW. These were generally the most
advanced developers with realistic possibility of coming to PTEC in the timescales indicated,
although 3 of these were only considering PTEC as a backup. The ability to accommodate at
least 2 berths of this size would seem appropriate. If the size (ratings) of each berth / cable
could be varied, this would reduce the risk of unallocated capacity at the site.
Given the projects highlighted in Table 1, 6 individual berths would seem appropriate.
6.2 Voltages
Nearly as many developers stated they would need to export power at 6.6kV as said 11kV.
Cables at both voltages, with the flexibility to change the voltage would be beneficial. This
could be achieved with multiple cables to shore and tap changers on the main transformer.
A separate cable to shore for each berth, would also enable accommodation of those
developers looking to keep their control equipment onshore or in their own hub, as well as
those not planning an isolator in their own turbine.
Given the number of developers who stated they would need an auxiliary power supply in
‘their’ cable, this element should be investigated. The cost of supplying this is likely to be
small when compared to the cost of the cables.
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6.3 Progress towards Design Freeze
Table 2 above summarises the considerations for the Rochdale Envelope coming out of this
consultation. This will be further refined with appropriate sample technologies to represent
these extremes, selected in collaboration with PTEC and the EIA team.
The current FEED programme should reach a design freeze in March 2014; however, there
is a requirement to accelerate this for the benefit of the EIA work; and therefore reach
design freeze as soon as possible
There may still be some flexibility after this date with regards to the size and rating of a
particular berth, including voltage; but the number of cables (and thus berths) as well as
the overall size of the project (20 or 30MW) will have to be fixed at this point. Other
elements that need to be fixed at the same time will be:
Size (extent) of site
Cables and routes as well as installation/protection measures (on and offshore)
Type of landfall
Location and size of onshore substation
Grid connection point
The Rochdale Envelope and associated technologies /number that define it
It should be noted that even after design freeze, these elements will not be set in stone
and if there is a strong enough reason for them to change then this may be accommodated.
Design freeze will be achieved following a review of the second issue of the design options
report and a design workshop with IT Power, Royal HaskoningDHV and PTEC. It will also be
dependent on an agreed strategy for the grid connection application process, the ground
conditions report and the cabling options report.
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APPENDIX A: DEVELOPER QUESTIONNAIRE
PERPETUUS TIDAL ENERGY
CENTRE LTD
PTEC Developer Questionnaire
7 INTRODUCTION
The Perpetuus Tidal Energy Centre (PTEC) is a managed test / demonstration facility for tidal energy
developers; suitable for the deployment of up to full scale single units and small arrays from prototype to
pre-commercial demonstrators.
The offshore facility will be a 20MW demonstration site located approximately 2.5km to the south of St.
Catherine’s Point, and will include grid connection via subsea cables as well as navigation aids and
monitoring equipment. For further details please see the ‘PTEC Project Introduction’ document.
7.1 Scope
The purpose of this industry consultation is to obtain a coherent list of requirements from tidal developers
that can inform the FEED study for the design of the electrical system and integrate effectively with the
consenting process to determine preliminary site layout, outline Rochdale Envelope, and input into the
EIA, infrastructure requirements and project design statement.
NOTE: The FEED consultation will not include discussions of a commercial nature; this will remain the
responsibility of the PTEC team.
7.2 Key Objectives
There are four main objectives for this developer consultation:
1. Obtain information to define the project requirements for the FEED Study, which will comprise:
Technical data relating to the device.
Infrastructure requirements
Deployment and recovery plans and requirements.
O&M plans and requirements.
Data to define the Rochdale Envelope and project design statement.
2. Understand the approximate deployment timescales expected by developers.
3. Understand the ideal services that they would require from PTEC.
4. Understand the ideal port and onshore support infrastructure requirements on the Isle of Wight.
NOTE: The details given by all participants in this consultation will be held in the strictest confidence
and will not be shared outside of the PTEC project team.
IT Power and PTEC are prepared to enter into confidentiality agreements with all who wish in this regard.
8 QUESTIONNAIRE
Question Answer
Genera
l
Would you be interested in
deploying a project at PTEC?
Please summarise your testing
programmes and (3rd party)
verification to date.
Tim
ing
Approximately when would you
be looking to deploy machines
there?
What would be the intended
length of deployment for your
project?
Sit
e d
esi
gn
How may devices would you be
looking to deploy?
Comments on the number /
layout of berths within PTEC?
Potential layout of devices and
infrastructure within a berth?
Devic
e d
esi
gn
Device configuration (axial
flow/transverse/other)
Surface piercing/floating/sub
surface
Foundation/mooring type,
number and design (e.g. gravity
base/piled)
Footprint of deployment
Number of blades, dimensions
and rotation speed
Electrical output – rated capacity
and voltage
Control strategy:
Pitch/stall regulation
(active, passive, speed
etc)
Type & location of
converters
Communications and electrical
isolation methodology
Connection to transmission
infrastructure
Inst
allati
on a
ppro
ach
Installation methodology
Installation equipment and
vessels to be used
Duration and seasonality
(seastate restrictions) of offshore
installation activity
Installation port requirements
(e.g. space, hard standings and
road access, etc)
Onshore support infrastructure
requirements
Oper
ati
on
al
and
main
tena
nce
consi
dera
tions
O&M strategy
Seastate restrictions for offshore
O&M
Personnel and vessels required
Planned frequency of scheduled
maintenance interventions /
surveys
Back-up electricity supply
requirement
O&M port requirements
Decom
m
issi
onin
g
Approach to decommissioning
Oth
er
Ideal services that a developer
would expect PTEC to provide
Other onshore support
infrastructure requirements
Key results of any prior EIA
studies
Willingness for sharing of data
(environmental monitoring)
Health & safety considerations