future technology development to meet the cost of energy challenge

Future Technology Development to

Meet the Cost of Energy Challenge

A summary report from the

5th Bristol Tidal Energy Forum

Regen SW October 2013

The Future of Tidal Energy The focus of the discussion at the 5th Bristol Tidal Energy Forum was the future of the tidal energy industry, concentrating on the steps required to take the industry from the latter stages of research and development through to commercialisation. Two interconnected questions were raised at the forum, which put this discussion in context:

What is the future levelised cost of energy (LCOE) for tidal energy?

What are the anticipated capacity and timescales of deployment required to deliver this LCOE?

Discussion around the possible answers to these questions underpinned the conference, with progress around tidal blades, installation vessels, offshore or onshore power conditioning and cabling representing a number of areas where improved performance and reduced cost will reduce the LCOE.

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The Future of Tidal Energy What is the future levelised cost of energy (LCOE) for tidal energy?

What are the anticipated capacity and timescales of deployment required to deliver this LCOE?

Achieving a future LCOE for tidal energy at and possibly below 18p/kWh was discussed at the event. Renewable UK’s LCOE forecast shows the anticipated cumulative installed capacity required to reach this sort of cost.

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Graph courtesy of Renewable UK – Tidal Stream Energy cost trajectory (logarithmic x-axis)

The Future of Tidal Energy 4

Metric Commercial targets for discussion Current performance

Capacity factor 25-35% Variable - site dependent

Availability 80-95% 50-70%

Capital cost £3-4m/MW £7-10m/MW

Operating costs 3-6% Capex/annum Highly variable

Lifetime 20years ~5years

Some table contents courtesy Max Carcas, EMEC – BTEF 5 speaker. Current and target performance figures proposed provided for discussion, please feedback via our Bristol Tidal Energy Forum Linkedin page – click the logo below

The table below shows some proposed target characteristics of the industry in its commercial form. These targets, drawing on discussion and presentations made at the Bristol Tidal Energy Forum are proposed for further discussion:

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http://www.linkedin.com/groups?gid=5186372&trk=my_groups-b-grp-v

The Future of Tidal Energy Each speaker provided insight from their own expertise on meeting the targets identified in the table on the previous page through areas of technological and economic development. Some of these priority development areas are already being investigated by the industry, and the presenters provided feedback on this progress. However, whilst the industry has made inroads on these topics all the areas identified need funding and support to move the sector forward.

The following short report summarises the priority areas of development highlighted at the forum (listed and linked on the right).

The speakers and a link to their presentations are provided overleaf.

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1. Electrical Infrastructure

2. Cost Optimisation

3. Tidal Turbine Blades

4. Vessels, Installation and O&M

5. Support Structures

6. Array Modelling

7. Finance, Warranties and Insurance

8. The Bristol Channel

Speakers and Topics Below and overleaf is the list of speakers and the topics they covered at the event. The presentations (where available) can be downloaded from the following page on the Regen SW website.

http://www.regensw.co.uk/events/regen-sw-events-/bristol-tidal-energy-forum-five

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Funding for offshore renewable energy David Hytch Lead Technologist – Offshore Renewables, TSB

An overview of the Offshore Renewable Energy Catapult and future projects Andrew Jamieson Chief Executive, Offshore Renewable Energy Catapult

When can private finance take over? Lucy Parsons Director of Risk Mitigation, Narec Capital

A route to the cost effective deployment of large arrays Jeremy Thake Head of Engineering, Atlantis Resource Corporation

Innovation at Marine Current Turbines Bob Colclough Naval Architect, Marine Current Turbines

Tidal energy technology for the Bristol Channel Ian Godfrey Marine Programme Manager, Regen SW

The HF4, a custom vessel to industrialise tidal energy Richard Argall Naval Architect, Mojo Maritime

The Pentland Firth and Orkney Waters Marine Energy Park Max Carcas External Liaison, European Marine Energy Centre (EMEC)

Tidal Energy Convertor Array Optimisation: in the Maze of the Minotaur Thomas Roc Oceanographer / Software Developer, IT Power

Innovation in the supply chain David Rigg Managing Director, Green Theme


















7 Electrical Infrastructure Resolving the challenges associated with offshore electrical infrastructure for tidal arrays is widely considered to be a priority area of development for the sector. The following key points for further technological development were raised and discussed at the forum:

High Voltage Direct Current (HVDC) – HVDC infrastructure is likely to be more economical than HVAC for connections greater than 70-80km from shore. This threshold represents the balance between power transmission efficiency and infrastructure hardware costs.

Power conditioning – tidal array electrical architecture must fulfil a complex mix of cost, efficiency and maintenance access requirements over different distances. It is not yet fully understood /agreed whether a) a cable per machine to shore; b) power conditioning per machine, then grouping to a single cable for transport per shore or c) collective power conditioning module with export to shore will represent the most suitable solution.

Wet mate connections – wet mate connectors provide flexibility and functionality for machine installation and retrieval, but come at a component cost and risk. Dry mate connectors represent a lower capital cost, but require greater intervention for connection and disconnection, increasing O&M costs. The balance of cost and technological advantage is not yet fully understood.

Back to Table of Contents



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Optimising device design to reduce costs and ultimately the LCOE is a key priority for many of the leading turbine developers. We heard updates from Atlantis Resource Corporation(ARC) and Marine Current Turbines (MCT) about the in-house tools they are developing and using to understand the best combination of device and array characteristics to minimise capital and operational cost.

Cost optimisation tools – software tools are required to model the life cycle costs of turbines and arrays as integrated systems. ARC and MCT both agreed that whilst there are no obvious single cost saving opportunities, significant cost savings can be made through combinations of factors (e.g. weight saving and consequential vessel options).

Standardisation of components - to increase volume and bring down costs and reduce technical risk associated with novel components was cited as a key area of development for the future of the sector.

Component life – many components will be designed with a 20 year life (MCT) and for those that can’t be, rapid change out / hot swap components will be required to minimise O&M costs and device down time. Both requirements present technological challenges for the industry.

Cost Optimisation (1 of 2)

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Diagnostics and condition monitoring – coupled to the challenges surrounding a 20 year component life is the remote conditioning monitoring of systems and components required to last that long. The ETI’s ReDAPT project amongst others seeks to answer part of this question, but new technology that provides reliable data collection and processing to establish the condition of these inherently valuable components will be required in a fully commercial industry where O&M access is expensive.

Turbine size – discussion over the economics of turbine size included reasoning for both ‘bigger is better solutions’ for rotors, powertrains and devices (e.g. multiple powertrains devices) and also the economic benefits of smaller, simpler turbines with, for example fixed pitch turbine blades, direct drive powertrains and seawater lubrication.

Cost Optimisation (2 of 2)



10 Tidal Turbine Blades (1 of 2)

With the National Composites Centre, specific expertise in the city’s two universities and a number of manufacturer’s in the region, composite turbine blades make a natural fit with the Bristol Tidal Energy Forum. As critical system components, advancements in the understanding of blade structural design, testing, condition monitoring, materials and more, are key areas of technology development for the industry.

Blade structure – with a different environment, duty cycle and loads, tidal turbines are unlikely to be a scaled down version of wind turbine blades in terms of structure in the future. ARC presented a possible approach where blades could be designed such that the hydrodynamic and structural requirements are provided by a structural carbon fibre skin, rather than a structural spar and hydrodynamically profiled, non-structural skin as is typical with wind turbines. Blade root systems that maximise efficient blade shape whilst transferring loads out of the blade and into the powertrain and support structure will also be an area for new developments.



11 Tidal Turbine Blades (1 of 2)

Blade size – the difference between a 10m and a 15m blade is a more than 100% increase in swept area and consequentially, power capture. However a longer blade compromises powertrain efficiency as shaft speed is reduced to avoid blade tip cavitation. Finding the right balance between these factors will be key to understanding the most efficient overall system.

Tidal blade testing – with its skills base in composite material design and engineering, composite materials manufacturers and end users in the form of turbine technology developers, Bristol is well suited to host a tidal blade testing facility and centre of expertise. Testing blades as well as developing standards and accreditation could provide a highly valuable asset for the industry.



12 Vessels, Installation and O&M*

The TSB has awarded two grants in the past year for the development of vessels specifically designed for the tidal energy industry; Mojo Maritime’s HF4 project and IT Power + KML’s DP Lite project. As project volume increases, bespoke vessels will be required to tackle sub-optimal use of vessels borrowed from the offshore wind and oil and gas sector.

Vessels – vessels optimised specifically for tidal turbine installation are required to increase capability and operational windows in high velocity environments. Mojo Maritime’s HF4 vessel will be capable of holding station in up to 10 knots of flow, unmatched by existing dynamic positioning, offshore construction vessels. Increased capability and vessel availability as well as reduced day rates will play a key role in reducing project costs for tidal turbine arrays.

Operational planning tools – marine operations planning tools are currently under development by companies such Green Theme and Mojo. These tools will be key to planning and delivering projects to cost, safely and on time.

Supply chain innovation – there is a big opportunity for the development of intellectual property (IP) in the tidal energy supply chain. As turbine technology developers focus on their core IP, numerous tools will be required to install, operate and maintain turbines, representing a strong area for technology development.

* Operation and Maintenance Back to Table of Contents

13 Support Structures Foundation and super structures to transfer load from and support the rotor(s), powertrain(s), control and power conditioning equipment as well as providing access for maintenance, continue to be a topic of discussion and innovation in the sector.

Support structures – systems from leading technology developers include multiple rotors on a single foundation; MCT’s surface piercing + cross beam structure; gravity and piled structures; monopiles and tripods; floating systems and more. With so much variation and difference in opinion, there is a clear opportunity for innovation and technology development in this area to identify solutions to match varying site conditions. Optimising support structures for strength, weight and ease of installation remains a key area of development for the sector.



14 Array Modelling Significant advances in the numerical modelling of tidal arrays have been made in recent years, as academics and industry have tackled the challenges of modelling the complex hydrodynamics and multi-scale challenges associated with turbulence, energy extraction, environmental impact and device interaction.

Data collection and sharing – validation of numerical methods using data from installed turbines and site characterisation will be key to improving model accuracy. Without accurate numerical modelling techniques, planning of large tidal arrays for maximum output and capacity factor will not be possible. Data on environmental impact for subsequent solutions to predict impact at different sites will be a key part of this knowledge exchange work.

Array optimisation – algorithms for optimising array layout within a capable numerical model will enable project developers to optimise energy extraction and minimise environmental impact in the key areas resource in the UK and around the world.

Innovation in modelling – numerical methods that can be run on desktop computers (rather than costly super computer type clusters) are required to enable faster, less specialist evaluation of sites and planning of tidal arrays (as has become the case in the wind industry)




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Finance, Warranties and

Insurance


Commercialisation of the tidal energy sector will require certification and validation of devices and array planning tools, to provide project developers, investors and insurers with guarantees of performance and availability.

Accreditation – certification of design methodology, components and systems and software tools is crucial to establishing a credible industry and raising finance.

Warranties – both manufacturer’s and third party (certification body – e.g. GL) warranties as well third party guarantees are required for project financing to progress and insurance premiums to be become cost effective.



16 The Bristol Channel (1 of 2)

Bristol has a unique tidal energy opportunity on its doorstep in the form of the Bristol Channel, with some of the largest tidal ranges in the world and appreciable tidal stream resource. The Select Committee for Energy and Climate Change and the Department of Energy and Climate Change have this summer put tidal barrages out of the picture. This does however leave space for alternative areas of technology development to exploit the resource. The Balanced Technology Approach (developed by Regen as part of the Bristol City Council’s Offshore Energy Programme) has gathered strong support from stakeholders, industry and project developers as an incrementally developed, multi-technology solution. The technologies proposed as part of this solution are at varying stages of development, but all require development work to be commercially deployed:

Tidal lagoons – tidal lagoons such as the Swansea Bay Lagoon project have a key role to play in the approach, as the technology closest to maturity (projects already under development and technology well understood). However there are areas for further development that have the potential to reduce costs and improve performance. Key areas raised at the forum were lagoon wall structures, low-head bi-directional turbines and scheme operational planning (potentially including multiple bays, pumped storage and phasing with other technologies).



17 The Bristol Channel (2 of 2)

Tidal Stream – with a tidal stream resource characterised by depths of 20-35m and flow speeds of 2.0-2.5m/s, the Bristol Channel resource is not the prime focus of current technology development. However, with significant progress in the development of smaller turbines from companies such as Tocardo, Schottel and Verdant Power it is likely that advances in turbine simplicity, deployment and support structures and tidal array layout optimisation will mean that shallower and / or lower flower sites such as the Bristol Channel will become economical in the near future, opening up tidal resource in the UK and around the world.

Tidal Fences – a number of tidal fence compatible turbine technologies (typically cross-flow type) are under development, with two such companies, Kepler Energy Ltd and SeaPower Gen represented at the forum. Development is required in a number of areas for the first tidal fences to be deployed. Areas identified at the forum include turbine development – only small demonstrations of cross flow turbines have been installed to date, and development is still required around rotor speed control, cross rotor wake interaction and modelling; dynamic head modelling – numerical modelling and in-field validation (requires relatively large installations) is required to demonstrate the complex challenge of developing and maintaining a dynamic head across the fence to exploit potential and kinetic energy.



The tidal energy industry is at a crucial point at present. With significant OEM (original equipment manufacturer) investment in the sector, progress has come on strongly in the last two to three years. However, to build a commercial industry with an attractive LCOE, innovation in a wide variety of areas of technology and economic development is required, as discussed at the forum and summarised in this short report. These areas of innovation represents a strong opportunity for the UK to continue to develop IP and retain its lead in the tidal energy industry. As illustrated by Max Carcas (EMEC) at the forum, taking inspiration from the growth of the wind industry, the potential opportunity is too significant to ignore.

Conclusions 18

Wind 1980:

• ~10MW installed?

• Typical turbine 75kW

• Capacity Factor 12% (1985, California)

• Annual average: 9kW

Wind 2012:

• >100GW Europe alone

• Typical turbine 3MW

• Capacity factor 30% (2012, California)

• Annual average: 900kW



The Bristol Tidal Energy Forum now has a Linkedin page, where you can network with other attendees, contribute to the discussion around the last event and propose themes for the next. We will be continuing the discussion raised by the questions at the start of this report online, please join in by clicking the logo

Conclusions 19

As with the Bristol Tidal Energy Forum event, the content of this report is for discussion and debate. Please provide feedback through the new Bristol Tidal Energy Forum Linkedin group (click the logo beneath) or by email. Please also join us for the next Bristol Tidal Energy Forum in March 2014 to continue the discussion.


future technology development to meet the cost of energy challenge

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