ISSUE 01 • 2013 DNV GL www.gl-group.com

ee nergy.nerg e fficiency. e ngineering. ırenewablesze

The Next Generation offshore uk The Missing Link simulation Virtual Experience certification Managing Risks CERTIFICATION OF OFFSHORE WIND TURBINES

NEW GUIDELINE | EDITION 2012

The updated guideline follows the main developments in the offshore wind industry. It contains latest testing conditions, safety systems and quality requirements.

Order your copy now at www.gl-group.com/glrenewables Photo: Halberg | Dreamstime.com

www.gl-group.com/glrenewables editorial

To Our Readers

Our young, dynamic industry is looking ahead to a bright future – provided that we succeed in maintaining public and government support. To do so we must make wind power more af- fordable. In this issue of energize renewables you will find a number of suggestions that could cut the cost of wind energy significantly.

For example, DNV GL engineers can design and tune algorithms for the onboard control- lers of offshore wind turbines to optimise energy capture while minimising loading and fa- tigue. This will save plenty of money (page 30). Advanced computer-based modelling using FEA simulation cuts costs by supporting equipment design, installation, availability and compliance. There is no better way to navigate the intricacies of offshore structural engineering (page 16). But the industry must also learn to cooperate and share know-how to bring down the costs of building wind farms (page 12).

RV Ahilan These and many other promising new technologies and perspectives are what renewable energy experts discussed at the EWEA Offshore conference in Frankfurt, Germany. In particular, innova- tive, diversified financing concepts for offshore wind projects are opening new doors. Find out more on page 24. While hesitant governments spread a sense of uncertainty, the UK’s ambitious wind energy programme demonstrates how a young industry can benefit from vigorous govern- ment support. Read in “The Missing Link” (page 10) what needs to be done to stay the course.

Offshore wind has made great progress in Europe over the past ten years. In its report “10 Years: 10 Lessons”, GL Garrad Hassan, now part of the recently merged DNV GL Group, looks back at ten years of offshore wind and lessons learned. Read our summary on page 8.

In spite of the bumpy start of the German “energy turnaround”, the offshore wind energy market is developing at a breathtaking speed. The industry’s standards must keep pace with technology and practice. GL Renewables Certification recently published its new “Guideline for the Certification of Offshore Wind Turbines”. Minimising risks and earning the trust of investors, insurers, operators and authorities are the main purposes of our certification work (page 30).

DNV and GL have now become a single company, DNV GL. With our resources combined, we look forward to a great future as a new, stronger force serving our customers in the renewables sector. The renewable energy story continues to be an exciting one. I hope you enjoy this edition of energize renewables!

Yours sincerely,

RV Ahilan President GL Garrad Hassan, Director, Renewables Advisory, DNV GL

01/2013 3 contents 01/2013

42 44 SYNERGY MEERWIND ENVIRONMENT Driving down Independent cer- Credibility through costs by industry- tification for safe- a verified carbon wide collaboration ty and reliability footprint report 14

28 30 22 38 08 10 MAINTENANCE STRUCTURES DOCKING INTERVIEW REVIEW UK OFFSHORE Service battle Ensuring integrity A new logistics Mike Wöbbeking Viable industry: Leading position: for the US while minimising concept for about guideline a decade of the key factors market costs – a challenge installations developments offshore wind for success

4 energıze renewables

12 profileinbrief

In Brief: DNVGL – Energy

IN THE ENERGY INDUSTRY DNV GL delivers world-renowned testing and advisory services to the energy value chain including renewables and energy efficiency. Our expertise spans onshore and offshore wind power, solar, conventional generation, transmission and distribution, smart grids, and sustainable energy use, as well as energy markets and regulations. Our 3,000 energy experts support customers around the globe in delivering a safe, reliable, efficient, and sustainable energy supply. GL Garrad Hassan and GL Renewables Certification are part of DNV GL.

GL GARRAD HASSAN, one of the world’s largest renewable energy con- sultancies with a staff of 1,000 at 44 locations in 26 countries, offers a unique level of service expertise across the lifecycle of onshore and offshore wind, marine renewables, and solar energy projects. Addressing all technical aspects of renewable energy applications, GL Garrad Hassan serves manufacturers, operators, investors, project developers, authori- ties, and the supply industry, providing engineering, optimisation, measurement and inspection services and software products.

GL RENEWABLES CERTIFICATION is a leading certification body primarily focused on the certification of wind farms, wind turbines and their components as well as marine renewable energy. At the forefront of know-how in renewables technology, it is abreast of all the necessary stan­dards and requirements and takes a harmonised approach in ensuring that these are met. Manufacturers, banks and insurers around the world rely on the state-of-the-art service provided by 34 GL Renewables Certification. STABILITY ABOUT DNV GL: On 12 September 2013, DNV and GL merged to form A new tower DNV GL. Driven by our purpose of safeguarding life, property and the misalignment detection service environment, DNV GL enables organisations to advance the safety and sustainability of their business. We provide classification and technical assurance along with software and independent expert advisory services to the maritime, oil and gas, and energy industries. We also provide certification services to customers across a wide range of 16 24 industries. With our origins stretching back to 1864, our reach today is global. Operating in more than 100 countries, our 16,000 SIMULATIONS FINANCE professionals are dedicated to helping our customers make the world Computer-based Financial structures: safer, smarter and greener. modelling for more diverse and turbine design international

01/2013 5 6 energıze renewables future trends

Whether it is about feeding wind power into the grid, developing intelligent on- shore and offshore wind farm concepts or introducing innovative measurement and testing systems – GL Garrad Hassan provides solutions for tomorrow’s wind energy technology. Photo: inakiantonana | iStockphoto

01/2013 7 future trends experience

Horns Rev. The Danish wind farm has demonstrated the industry’s ability to learn.

A Decade of Offshore Wind – An Industry Grew up

Following some early setbacks, offshore wind power has acquired the experience and track record it needs to stand its ground. Policy uncertainties remain

In the autumn and winter of 2003, the land- formance. In the ten eventful years since its construction mark Horns Rev offshore wind farm in Denmark we’ve discovered just how misplaced assumptions were was in trouble. Serial defects in important tur- that offshore wind could be tackled in the same way as bine components came to light which threatened the viabili- onshore wind or offshore oil and gas. Offshore wind is off- ty of the project and, by inference, the future of the offshore shore wind and there is nothing else quite like it. wind industry. If the owner and turbine manufacturer hadn’t recognised the extent of the problems early and taken radi- The Cost Challenge cal remedial action, offshore wind might have been over be- We have learned the true value of marine spatial planning fore it really began. But since its eventual completion the in smoothing out the development process and preventing following summer, the 160-megawatt wind farm has per- expensive delays. Financing billions of dollars worth of cut- formed brilliantly and set the bench- ting-edge wind farm engineering requires an entirely new ABSTRACT mark for all subsequent projects. approach and, slowly but surely, the innovation needed to

The offshore wind industry has The Horns Rev story can be ensure the future of offshore wind is happening. Govern- learned from early mistakes and thought of as a metaphor for the ments looked on with dismay as costs rose inexorably when demonstrated its viability broader industry: painful early ex- conventional theory held that they should be doing exactly Politicians must support offshore wind more vigorously to reduce periences giving way to better un- the opposite. But there are now clear signs that we are over

its costs and stabilise the market derstanding and improved per- the hump and costs are starting to come down. Photo: DONG Energy/MEDVIND/Bent Sørensen

8 energıze renewables There is also now a much better understanding of the industrial goals and hurt supply chain players, especially unique demands of the technology. As new ways have those who invest boldly in the sector to gain “first mover” been found to manage contracting arrangements, breath- advantage. Independent developers, whose business mod- taking advances have been made in our understanding of el is built on a steady flow of new projects, are hurt more how to design a fully integrated offshore wind power sta- than utilities which have more diverse interests. The overall tion. “Construction risk” is no longer a term which strikes effect is a gradual disillusionment, especially among the terror in the hearts of financiers. From a shaky start, off- parts of the industry most vital to its success. Offshore wind shore wind has found its sea legs and a wiser, stronger projects cannot be mass produced. No two projects are the

industry is setting its sights on the future. Fixed offshore same and different approaches are still required from one wind has demonstrated that wind energy works at sea and, to the next. The best way to make sure that offshore wind with developments in Japan, Norway, Portugal and else- can continue to deliver large-scale, carbon-free and secure where, floating turbines are starting to make inroads into electricity generation is for governments to clearly and the mind-bogglingly big wind resource that is available be- realistically set out the role offshore wind will play in the yond the confines of shallow water. long term. Only then will supply chain companies have the

FLOATING confidence to invest in the innovation that will really push Waiting for Government Support TURBINES. performance up and costs down. A new concept But the single most important lesson learned is We all have a crucial role to play, too. Clearly, articulat- to take advan- that achieving cost reduction depends on build- ing the benefits of making the most of our fantastic natu- tage of stronger, more consistent ing plenty of wind farms. And to do so we need ral wind resources is vital to sustaining the political support winds on the the confidence of investors, developers, turbine needed for offshore wind to fulfil its potential. Offshore open sea. makers and everybody else in the supply chain. wind has a great story to tell and it is incumbent on those The fact that confidence is often undermined by policy un- who want to see it succeed to tell it. If we don’t, someone

certainty is the biggest threat offshore wind faces. else will. OFR Overcoming uncertainty will take more than warm words and overinflated targets. Unrealistic expectations for DNV GL EXPERT: offshore wind are damaging for governments, developers Oscar Fitch-Roy Strategy & Policy Studies and the supply chain. A failure to deliver the anticipated Phone: +44 117 972 98 78 capacity may jeopardise governments’ environmental and E-Mail: [email protected]

01/2013 9 future trends market

The Missing Link

The UK has been pushing its offshore wind energy capacity unlike any other country. The national gov- ernment’s industrial policy, mass production and sub- stantial domestic value-add are key factors for success

“Building an Industry” was the unofficial motto of 4,000 megawatts, are converting powerful sea wind to of this year’s offshore conference of the British electricity today. That is ten times the capacity installed in wind energy association renewableUK. It may Germany. So what industry is it they want to build? seem strange at first, considering the UK’s status as undis- puted world champion in offshore wind with the record Dependence on Imports numbers 20; 1,065; and 4,000: twenty offshore wind farms, The answer is surprisingly straightforward: a major portion comprising 1,065 wind turbines and a total rated power of the wind turbine components are imported. In fact, of

ABSTRACT

The UK leads the world in installed wind energy generation capacity Strong government support has been a key factor in accomplishing this To drive down costs, the nation will have to produce more components domestically

10 energıze renewables Turbine. The success of offshore wind energy depends on the political framework. Photo: Michael Halberg/Dreamstime.com

the power heads sitting atop every tower – highly relevant tional interest,” says Jörg Kuhbier, Chairman of the Board parts in terms of both prestige and economy – 100 per of the German OFFSHORE WINDENERGIE foundation. cent are imported from abroad. Here the supply chain has Offshore wind creates jobs and drives the economy. a wide gap that needs to be closed; a gap that clearly vio- This is why British politicians, whether centre, left, right or lates the principles underlying the British offshore initiative. green, are willing to go to extremes in support of British “The British have always viewed offshore wind energy and wind energy. However, this perspective raises expectations its vigorous expansion as an industrial policy project of na- which may rapidly lead to disapproval of the offshore

World Champion. 20 offshore UK wind farms with 4,000 MW installed capacity are in operation.

01/2013 11 future trends market

miracle if they remain unfulfilled. It is therefore im- ENERGIZE: The last offshore exhibition and confer- perative for the UK to generate as much value as possible ence in Manchester made quite an impression seeing inside the country. the government’s commitment to the offshore wind industry. Can you explain the background of this Two Sides of the Same Medal strong support by the British government? The motto makes another point: it alludes to the British DEN ROOIJEN: The UK government recognised the po- drive to develop offshore wind banks on wind energy as tential of offshore wind energy early on. As a country a large-volume business. Many large orders for turbines we are blessed with one of the best wind climates in will help this vision materialise. Economies of scale will not the world and we have lots of shallow seabed that is arise from 89 turbines but from 890. “Driving the costs suited for turbine foundations. down” and “building an industry” are two sides of the Also, the high-voltage transmission grid reaches out same medal. Production costs will not decrease significantly to the many existing and former industries on the coast, until turbines are manufactured in large series of hundreds so grid connection costs are reasonable. To develop this of identical machines, as planned for the Dogger Bank potential, legislation was introduced that encouraged

Round 3 project. JI development of offshore wind.

ENERGIZE: The UK is the world champion in using offshore wind. How did your country achieve this DNV GL EXPERT: Ian Finch position? Global Business Development Manager, Offshore Wind DEN ROOIJEN: Personally, I believe the success of our Phone: +44 117 972 9900 development has been the coordinated approach be- E-Mail: [email protected] tween the government’s financial support regime and our structured approach to seabed leasing. We have made sites available to the market in a systematic way, through leasing rounds. We have learned that it helps to identify suitable areas of seabed first, and then to tender these to the market for development. This allows strategic issues and stakeholders to be Leading Market identified right at the start, and we can work together In 2012 the growth in offshore wind was well above to find the best solutions for everybody. We are also the average growth rate of the onshore wind sec- quite serious about our tenders. So, as a developer, tor. Thirteen countries are operating offshore wind- when you win development rights to the seabed, then farms, eleven of them in Europe. The Top Five in you are in a pretty good position: you know what is- offshore wind are the UK, Denmark, China, Belgium sues need to be addressed in consenting and develop- and Germany. In 2012, the UK represented three ment, and you know the financial framework. quarters of the global offshore wind market.

12 energıze renewables Interview. Huub den Roijen heads the Offshore Wind unit at The Crown Estate.

construction expertise as well as top-flight universities and We make sites legacy talent from heavy engineering as well as our new high-value capability in electrical and control systems. This available is exactly the right springboard to grow a sustainable sup- ply chain. to the market ENERGIZE: What can The Crown Estate do in terms of in- creasing the local contribution? ENERGIZE: One of the main issues during the last ten DEN ROOIJEN: Economic benefit to the UK is an important years has been closing the supply chain gap. It is amaz- criterion for winning a CfD contract. These contracts for dif- ing to hear that from the world’s oldest industrialised ference are the new mechanism for financial support. They country. Can you comment on that? provide a fixed-price feed-in tariff to windfarm operators. DEN ROOIJEN: It is true that manufacturing of commodity At The Crown Estate we are working with the government items and highly labour or energy-intensive products has and developers to ensure that UK companies are placed in increasingly shifted from a UK base to overseas. Recent the best possible competitive position. This will make it eas- UK governments have underlined the importance of a bal- ier for developers to solve the supply chain puzzle. anced economy and have shifted the emphasis back to- We want UK companies to compete successfully for wards manufacturing, with a focus on high-value engineer- offshore wind business – not only in the UK but also in the ing and products. rest of the world, of course. We have very strong players For offshore wind specifically the sheer size and scale for example in steel and concrete fabrication, in manufac- of the elements that make up a windfarm, from turbines turing of gearboxes, generators, control systems, electrical to blades to towers and foundations, means that water- infrastructure – you name it. What we don’t have are major side production and assembly close to the final offshore turbine manufacturers. We believe that the opportunities of locations is generally the most cost-effective way of de- a continually growing market and a very dedicated govern- livering the infrastructure required. Linked with this is our ment and workforce will persuade manufacturers to set up world-renowned expertise in offshore oil and gas, offshore shop here in the UK.

01/2013 13 future trends collaboration

Flat-Out Rivalry Is A Fool’s Errand

With more than 2,000 offshore turbines in- The ability of the wind power industry stalled and generating electricity, the offshore to keep the cost of energy in check wind sector has come a long way since the is closely related to its willingness to Vindeby wind farm entered operation in the Baltic Sea in share know-how. It is time for competi- 1991. The industry’s ability to deliver power generation tors to overcome anxieties and engage capacity at scale, under hostile marine conditions, is no in a fruitful exchange of experience longer in doubt. But despite this considerable success, and best practice the vexed issue of cost remains, and a grand bargain has been struck with governments – we, the offshore wind energy community, deliver cost reduction and they sup- “How does one build an offshore wind farm port the market. If costs do not fall, there will be no cheaply and safely?” But instead of recognis- market. Cost is the enemy and to tackle it prop- ing that the answer would be much easier erly requires many things: innovation, invest- if we worked on it together, learning les- ment and a supportive policy landscape. sons from those who have gone before, we create silos, keeping our thinking Learning Our Lessons in our own companies and attempt But most fundamentally, it requires a change to do it alone, while occasionally STOP SQUABBLING. in mindset. We need to leave behind the ex- Many issues can trying to peek over our competi- am-room mentality where all the indus- only be resolved by tors’ shoulders to see what they try players are working on their own, working together. are doing. jealously shielding their answers from There must come a point in the inquisitive gaze of everyone else. time, as did in the oil and gas, We all know what the question is: power-generation and telecoms sectors, when we realise that flat-out rivalry is a fool’s errand. If we are not careful ABSTRACT this misguided approach might lead to higher pric- Cost reduction is critical for the long term sustainability of offshore wind. es, greater technical problems and offshore wind As long as the sector is overly knocking on the politicians’ door for more money. As protective of their experience, costs will remain stubbornly high an industry, we should have the confidence to acknowl- Industry wide collaboration is essential edge what has gone wrong to give us a better chance of to driving down costs avoiding the same mistakes. The cliché, “Those who do not

14 energıze renewables Best Practice. Sharing knowledge would benefit both the industry and its customers.

efits drive wind farms elsewhere to this substation size. Standardisation is never easy but offers real cost-reduction benefit, and the precedent shows what can happen when regulators and industry work together. There is great po- tential for further collaboration across borders. We all have to cut costs and the UK, Denmark, Belgium, Holland and Finland each have their own cost-reduction programmes. Surely the present situation will lead to unnecessary dupli- cation. If we could instead think in terms of comparative study history are condemned to repeat it”, rings particularly JAPAN. Ocean advantage and identify who is best placed to true in the offshore wind sector, especially with regard to depths, weather deliver the respective cost reduction measures extremes and the cabling problems that continue to dog the industry. We and coordinate them across Europe, we would remoteness of need to overcome our fear of ignominy and be more open best-suited have a much more effective approach. EU-wide

Photo: Michael Halberg | Dreamstime.com about what we are doing. onshore industry collaboration like this would be a sign Offshore wind is new and no one has ever done what locations are of true maturity. key challenges. we are trying to do. We will not get it right at the first Beyond Europe, the recent announcements attempt. The mature thing to do, the right thing to do, in Japan, the US and China show the huge global poten- is to discuss it, to collaborate so that we, as an industry, tial of this sector. While it is easy to talk about the benefits can make good on the global potential. Cooperation ap- of cooperation, we should not be in any doubt that such plies equally to benchmarking of performance. Yes, it is a combined effort will be hard to deliver. But these are nerve-wracking opening up your product to people who all things that those of us who want a bright future for may well be competitors. But everyone benefits. You know offshore wind can do for ourselves. We just need to take how you are doing and where you need to improve, and a deep breath, think about the bigger picture and start offshore wind as a whole benefits from improved standards talking to each other. This is the first step towards a truly and lower financing costs. Gas turbine manufacturers do it, mature cost competitive industry – one that is nearly within

so why can’t we? our grasp. PR

Embrace Collaboration DNV GL EXPERT: A great example of collaboration is provided by the recent Paul Reynolds Strategy & Policy Studies German standardisation of 900-megawatt substations and Phone: +44 7500 830 565

Photo: Andrew Parfenov/Yobidaba | Dreamstime.com | Dreamstime.com Parfenov/Yobidaba Photo: Andrew cables. It will be interesting to see whether the cost ben- E-Mail: [email protected]

01/2013 15 future trends simulations

Safer, Smarter, Greener through “Virtual Experience”

There is no better way to navigate the complexities and intricacies of offshore structural engineering than advanced computer-based modelling. Simulation tech- niques provide detailed insight into the properties of a ship or turbine design

Traditionally, the design and operation of ships Ensuring compliance with regulations and offshore structures have been based on ex- Ensuring high availability/utilisation perience. This is still true to some extent, but Promoting innovative designs and procedures increasingly we rely on “virtual experience” gained from dedicated simulations, particularly for young and innovative Today simulations play an important role in all phases of the industries such as offshore wind power (OWP). Advances lifecycle of offshore wind farms, including: in simulation and computer hardware technology have led Concept development and design to a multitude of applications that were either unthinkable Installation in the past, or approximated by more expensive and/or less Operation and maintenance accurate model tests. From the customer’s perspective, simulations serve to These phases are discussed in the following, looking at support business processes by: OWP installations, installation and maintenance support ships, and selected other equipment.

ABSTRACT

Advanced FEA simulation technol- ogy is extremely valuable for the offshore wind industry

Software. Advanced Simulation cuts costs by supporting equipment design, installation, modelling avoids the costs and availability and compliance as well risks of trial-and-error engineering. as condition-based monitoring

16 energıze renewables Model. Flow analysis for hull optimisation of an offshore supply and maintenance vessel.

Supporting Design, Ensuring Compliance design process and its results dramatically. OWP mainte- The OWP industry is a young and, by necessity, very inno- nance vessels are good candidates for formal hull optimi- vative industry. Innovation unlocks new riches but also in- sation where fuel efficiency, stability and seakeeping must volves risk as we venture into unknown technological ter- be reflected in the optimisation model to find CFD. The study ritory. Simulation allows us to build “virtual experience”, good trade-offs. of the interac- ensuring not only the feasibility but also the efficiency and CFD is applied in virtually every stage of an tion of liquids safety of an envisioned concept. This applies to both equip- offshore wind farm project. Naturally, the eco- and gases with surfaces requires ment and procedures. nomic viability of an offshore wind farm de- powerful For example, modern design practice employs CFD pends on the wind conditions, the ability of computers. (computational fluid dynamics) and formal optimisation to the wind turbines to convert the wind into en- find the optimal shape for a particular ship hull or the ro- ergy, and the complex interaction between the individual tor blades of a wind turbine. In numerous projects, para- turbines. CFD is employed for top-level analyses of entire metric shape variation, advanced optimisation models and wind farms, for intermediate-level assessments of individ- powerful computer hardware have shown to improve the ual turbines, and to take a closer look at individual

01/2013 17 future trends simulations

components such as blades, even a local blade pro- certainty factor in structural assessments. A detailed struc- file, on the lowest level. Traditional wind tunnel tests are tural analysis therefore usually requires certain additional increasingly supplemented or even substituted by virtual simulations to determine the load distributions (variable in CFD testing. space and time), including: OWP structures must be strong enough to withstand the most severe weather conditions. International and na- Long-term spectral distributions of wave loads for fa- tional regulations as well as classification society rules serve tigue analyses, based on linear seakeeping methods as guidelines for assumed worst-case scenarios, such as the Extreme wave scenarios, including freak waves, using highest wave to be expected in a particular region within a a free-surface RANSE (Reynolds-averaged Navier-Stokes 100-year period. Specifying such worst-case scenarios and equations) solver associated probabilities is important for risk-based design but will not be discussed here. In general, the simulation The state of the art in seakeeping simulations has advanced expert follows user specifications or common practice. In dramatically over the past ten years thanks to the advent of most cases, the assumed loads are the most significant un- simulation methods capable of handling arbitrary geome-

Simulation. Finite Collision. FEA element analysis of a analysis of a ship bolted connection on an ramming a wind off-shore wind turbine. turbine tower.

CASE STUDY Strong Connections

FutureShip was asked to determine found to exceed the allowable limit. risk assessment is required to obtain ap- whether the bolts joining the drive The affected bolt connections were re- proval for OWP installations. Formal risk train components (hub, main shaft, designed to ensure sufficient strength. assessment procedures based on FMEA frame, generator) on a new 7-mega- The OWP industry is under scruti- (failure mode and effect analysis) or watt offshore wind turbine design were ny by authorities and pressure groups similar approaches combine probabilis- strong enough. Accounting for bolt pre- alike. Both safety and environmental tic frameworks with simulations, espe- tension, gravity and design loads such impacts are subject to ever tighter reg- cially for the “effects” part of an FMEA. as bending moments at the rotor hub, ulations. Simulations play a vital role in Similar risk assessment studies are FutureShip performed nonlinear FEA ensuring compliance. They are widely performed for the cable connections simulations to study the ultimate and accepted by national authorities­ as “en- to investigate navigational risks for fatigue strengths of the bolt connec- gineering proof” of compliance in the ships caused by cable installation and tions. In some cases the stresses were approval stage. Frequently a formal maintenance.

18 energıze renewables CASE STUDY Close Encounters

To satisfy German approval requirements, FutureShip was asked to determine the ship collision risk for a planned offshore wind farm in the North Sea. Based on a vessel traf- fic analysis, FutureShip estimated the - prob ability of both powered and drifting ves- sels colliding with one of the wind turbines, accounting for environmental conditions such as wind and tidal currents as well as risk miti- gation measures. The computed potential collision frequency met the acceptance criteria of the German authorities.

Traffic Hazards. Wind farms in the vicinity of busy ship lanes pose a collision hazard. Vessel traffic analysis for an OWP risk

Photo: Centrill | Dreamstime.com assessment study (right).

tries, mooring and multi-body interaction, and of capturing construction solutions for tankers. Today, collision analyses all relevant physical phenomena, including breaking waves are regularly performed for ships with the “COLL” class and viscous effects. notation, as well as for offshore wind farms where authori- Finite-element analyses (FEA) for global strength assess- ties require proof of collision tolerance. ment are widely applied to ships, OWP structures and sub- systems (such as masts, blades, gear boxes, connections, Managing the Crucial Installation Phase etc.). In most cases these simulations use linear-elastic Special analytical requirements apply to the installation analys­is, evaluating the structure before the material reach- process of OWP structures. The transit phase may involve es its yield point. OWP structures frequently require a more heavy-cargo transport with exceptionally low freeboard. sophisticated approach, such as fatigue or collision analysis. Jack-up installation ships are most vulnerable just before or The latter plays a major role in the approval process. Ger- during touchdown of the jack-up legs. Dedicated simula- manischer Lloyd has broad relevant simulation experience tions are frequently requested for risk mitigation to deter- and was the first classification society to publish a standard mine the operational limits and issue operational permits for the evaluation and approval of alternative design and accordingly. Operability restrictions may have a nega-

01/2013 19 future trends simulations

Maintenance. Specialised SWATH service vessel from Abeking & Rasmussen docking at a wind turbine jacket leg.

tive impact on availability, an economic concern of paramount importance in OWP operations. Operational limits for installation and maintenance are specified based on sea states and vessel re­sponses deter- mined in seakeeping simulations. These analyses increas- ingly employ viscous CFD simulations that are capable even of simulating breaking waves. The best trade-off between accuracy and resource requirement is often achieved by CASE STUDY combining various approaches. Long-term

Successful Operation Measurements for Repair and maintenance of remote offshore wind turbines is expensive. Ensuring high availability is therefore a key ob- Better Simulations jective. It is achieved primarily by implementing three strat- A joint industry project investigated the loads on egies: “design for availability” (ensuring system robustness), wind turbines and tender boats during connection “monitoring for availability” (condition-based maintenance impact. Sensor equipment and a long-term data to avoid downtime), and simulation applying FMEA or re- acquisition system were installed on an operator’s lated formal risk assessment techniques to OWP systems tender boat. The long-term measurements delivered and subsystems in the widest sense, including operational reliable operating condition data, providing insight procedures. that helped to validate simulation models and guide Fatigue damage is a typical application scenario for FEA the design of an improved fender system. simulation. Using load spectra tailored to the wind farm area as input parameters allows engineers to determine the fatigue life of a structure. Unavoidable random varia- tions in structural fatigue can be accounted for by defining have proven to be highly effective in troubleshooting wide safety margins. This approach is well-suited for ana- vibration issues. lysing masts, blades, gearboxes and other key elements of an OWP turbine. Monitoring for Availability The ability to troubleshoot wind turbines quickly is In some situations, accepting degradation and planned essential for rapid design improvements, which are vital replacement of system components is more economical for the OWP industry to avoid propagating design flaws than designing for complete avoidance of replacements. and the associated costs. OWP structures are especially This may apply to both machinery and structures, where susceptible to vibration. When rotors are exposed to in- corrosion is often accepted as unavoidable. The condition homogeneous inflow and vortices generated at slender of these system components can be monitored within the masts they induce vibrations which may lead to material scope of a condition-based maintenance scheme to ensure fatigue. Combinations of measurements and simulations timely replacement and avoid unscheduled downtime.

20 energıze renewables Condition assessment schemes for maritime struc- invaluable asset for FutureShip’s engineering work. While tures are by no means a new concept. However, there is an simulation is an enormously powerful and versatile tech- emerging trend to combine condition monitoring systems nology, owning advanced simulation software alone is not with FEA models. This new approach makes it possible to enough. Rather, it takes expertise, experience and the right assess the residual strength of partially corroded structures. balance between level of detail and resources employed The same type of simulations forms the basis for risk-based (time, manpower) to use virtual modelling techniques suc- inspection schemes. cessfully. Only the right combination of software, hardware and expertise will unlock the true value these advanced en- Simulation and Measurements gineering methods can deliver. VB Simulation can be supplemented or even substituted by measurements. Detailed measurements are used to validate DNV GL EXPERT: simulations or calibrate simulation parameters. The steady Stefan Deucker FutureShip Engineering Services flow of feedback data FutureShip receives from field ser- Phone: +49 40 36149-8812 vices and its own dedicated measurement specialists is an E-Mail: [email protected]

Critical point. Jack-up platform in waves during touchdown.

CASE STUDY Steady Push-Ups

To determine the operational limits of an OWP in- and then performed seakeeping calculations using a stallation vessel during wind turbine installation op- commercial panel code to determine the overturn- erations, FutureShip investigated the limiting sea ing moments and design loads, and ultimately derive state conditions, design loads and induced stresses the operational limits. The computed loads were ap- for the legs and the jack-up system, especially during plied to an FEA model to assess the stresses induced the most critical phase, the semi-jacked condition. into the structures. The resulting operational limits FutureShip first established the drag coefficients for showed that the legs and jack-up system were strong the fully extended legs using viscous CFD simulations, enough to withstand the expected maximal loads.

01/2013 21 future trends logistics

Docking Turbines

The installation of offshore wind farms is expensive. Wärtsilä and Bugsier have developed a new logistics concept to separate the transport and installation activities

Perhaps more than in any other industry, the old is handled by the tug, which takes over the barge as a push- adage “time is money” is true for maritime tech- ing train. The installation dockship is named after the float- nology. And the reason is both elementary and ing cargo dock into which the fully laden barge is docked. elemental. During work at sea, any delay involves the risk Like a jack-up platform, the dockship stands firmly on the that the possible window of acceptable weather may elapse. seabed and is thus independent of wave motion. The barge is This in turn means that work would have to cease and one docked by the tug with the aid of steerable propulsors which, would have to wait for the next possible window, while keep- just like thrusters used purely for manoeuvring, are controlled ing costly equipment at the ready – all too often for an un- from the tug’s bridge. The installation dockship then com- known period. pletes the installation according to the standard procedure: The offshore experts of the ship and offshore technol- setting the tower in place, mounting the nacelle with hub, ogy group Wärtsilä and the German towage company and hoisting the rotor star. In the meantime, the transport Bugsier have developed an installation concept for offshore barge has long since left for the base harbour to fetch the wind turbines which, although it cannot extend the weather next batch of components. The key process is the docking window, can utilisze it much more efficiently. The core idea is and undocking of the barge. “Our goal is to ensure that the to separate transport and installation by deploying an “instal- process also functions reliably at significant wave heights of lation dockship”. The chief advantage of the new concept is two metres,” says Carsten Wibel. that it is then possible to commit the expensive installation vessel totally to its primary task. By berthing the transport Up to 50 Per Cent Time Saved barge aboard the dock-ship it also avoids the offshore dy- The time – and hence money – saved lies namic vessel-to-vessel transfer of components, which is a ma- ABSTRACT precisely in the separation of the tasks re- jor weakness of most other proposed feeder-vessel scenarios. Wärtsilä and Bugsier have quired for transport and installation. This al- developed a new installation concept for lows more efficient utilisation of a weather Separating the Tasks offshore wind turbines window than when the installation vessel “Three years ago, we started to develop the concept,” says Using the available has to perform not only the installation but weather window for the Bugsier project manager Carsten Wibel. “Much too much erection of wind turbines also the transportation of the wind turbine. time and money was being expended on transferring the saves time and money Model calculations carried out by components.” This is not the case with “J-LASH”, as the de- Bugsier and Wärtsilä indicate that consid- velopment team have dubbed the dockship concept. J-LASH erable time savings are indeed possible. An analysis of the – short for “Jackable Lighter Aboard SHip” – consists of three procedural steps showed that, with conventional installation elements: An installation jack-up, feeder barge and tugboat. methods, three offshore wind turbines can be erected within Transportation from the base harbour to the construction site a weather window of 98 hours. By applying the J-LASH con-

22 energıze renewables Changing Generations

The first generation of jack-up represent the current state of Despite their lack of firm platforms were not equipped with the art. support on the seabed, they are propulsion systems; they were soon The fourth generation, semi­ able to operate largely indepen- joined by cargo ships converted submersibles carrying the fully dently of wave action. The term to jack-up platforms – the second assembled wind turbine to the “fifth generation” for the J-LASH generation. Self-propelled jack-up site, is still in the conceptual design concept has not yet come into platforms, the third generation, and modelling stage. widespread use.

cept, 4.5 units can be installed in the same time – an increase an extremely low draught. It is therefore possible to load the of 50 per cent. If the working steps are analysed, it becomes barges in harbours that, owing to the shallow water, cannot clear the great amount of time needed for the third-gener- be served by the installation vessels of the third generation. ation installation units must be ascribed mainly to the two- The question remains, however, as to whether an installation fold jacking that is required in the base harbour and at the concept with fifth-generation vessels is financially viable when construction site. the fourth generation – semi-submersibles without a jack-up The transit time is a burden on rapid turnaround, all the – have not even been built yet. “We are currently engaged in more so because it ties up the most cost-intensive unit in the discussions with several customers,” comments Wibel. JI installation fleet – the installation vessel. J-LASH, on the other hand, remains on site and is “fed” by the transport barges. DNV GL EXPERT: In this way, J-LASH dedicates the weather window to the pri- Chris Garrett Offshore Engineering and Consulting mary task for which it was designed, and does not waste any Phone: +44 117 972 9775 time on transportation. Furthermore the feeder barges have E-Mail: [email protected]

01/2013 23 future trends finance model

Offshore Wind Finance: Strength through Diversity

With the dimensions of offshore wind farm projects increasing almost exponentially, innovative financing schemes are needed. Inspiration comes from overseas

In the cool, shallow waters, not far from the Recognising that the utility equity model has its limits, sugar beet fields of the Danish island of Lol- industry leaders and governments fret the utilities’ pockets land, sits a little wind farm called Vindeby. might not be deep enough to fund the ambitious deploy- With its eleven 450 kW turbines, Vindeby is unremarkable ment targets set by several European countries. However, but for the fact that it is Europe’s – and the world’s – first maturing technology and a better understanding of the as- and oldest offshore wind farm using balance sheet funding set class means there is good news in Europe which could from Elkraft, a Danish utility which well spread across the Atlantic. Since 2010, a more diverse ABSTRACT later became part of DONG Energy. range of offshore wind finance structures have started to Until recently, offshore wind Since Vindeby was built more than emerge (Figure 1). Institutional investors including pension farms were mostly financed by major utilities 20 years ago, much has changed funds such as PGGM and Japanese trading houses such as Financing structures are in European offshore wind. Tough Mitsubishi Corporation and Marubeni have made substan- becoming more diverse and engineering lessons have been tial investments. international learned, new technologies have To stay on track, Europe’s offshore wind business will been developed. The finance model has not changed near- need to find new sources of debt and state banks such as ly as rapidly. But changes are afoot. the EIB and KfW will remain a feature of the landscape for some time yet, but the entry of new sources of equity is a Good News in Europe welcome addition to the European sector. Of particular in- Non-commercial finance from multilateral funding organi- terest is the involvement of North American players in sev- zations (MFOs) like the European Investment Bank (EIB) and export credit agencies such as Japan’s NEXI may play a sig- nificant role in attracting senior commercial debt. But until recently offshore wind farm construction was funded large- ly by major utilities. While utility equity was ample to get early projects up and running, the scale and technical risk of big offshore wind, combined with fragile utility balance sheets has called its sustainability into question. European utilities are also reluctant to use project debt finance due to its impact

on their already strained credit ratings. Photo: London Array/Mark Turner

24 energıze renewables 01/2013 Array July 2013. farm, opera- tional since world’s largest wind illustrates thediversificationinfinancestructures. investment inEurope bysource from thestartof2011 London Figure 1.Achartofthecumulativeoffshore windCapEx 04/2011 06/2011 08/2011 10/2011 12/2011 02/2012 04/2012 06/2012 08/2012 10/2012 12/2012 02/2013 04/2013 06/2013 .

The “The entryofnewstakeholdersintotheoffshore windbusi This demonstrates how a diversity of new financing op financing new of diversity a how demonstrates This Tokyo-Mitsubishi UFJ and Siemens also committed to the Cape Wind project. Utilityfinancingisnotablyabsent. Cape Wind com financial the that recentprojects,demonstrating eral and most crucially reveals the belief that much of the en the on set firmly eyes waters, US in dropanchor to areset financed the Anholt wind farm off the Danish coast, which gineering experiencegainedinEuropean watersisdirectly decision reflects growing interest in the US offshore market growing seaboard. potentialalongtheeastern uses thesameSiemensturbinesproposed forCapeWind, this dependencyandunshackling thevastpotentialof tions isenablingtheUnitedStates toleapfrog theearly transferable totheNorthAmericancontext. the NorthSea,theirEuropean andJapanesecounterparts the Atlanticbefore gettingcomfortablewiththerisks. from thesea,”saidJens-PeterSaul.JustasNorthAmerican vestment in the Cape offshoreWind project. Having already ness willclearlyboostthemassivedevelopmentofenergy munity isnotwaitingforoffshore windto make itacross way, recently announcinga$ 200millionconditionalin PensionDanmark is perhaps an obvious first mover.first obvious Theiran perhaps is PensionDanmark European, utility-backed model of development. Breaking Meerwind Meerwind investors are getting comfortable with funding projectsinfunding with comfortable aregetting investors US Offshore –aDifferent Approach? broader UScapitalmarketsremoves apowerfulbarrierto Financing Crosses the Atlantic €1,200 Other seasonedoffshore investorssuchastheBankof PensionDanmark isoneofthecompaniesleading m m €1,320 Anholt m m

€850 NorthwindNV - - - - - m m customed to much larger financing deals. Projects such as Projects such deals. financing larger much to customed of comparableinvestmentsizetoalargeoffshore project. ed to develop an offshore industry of the size envisioned ownership and finance structures that have come an have that structures finance and ownership awfully longway, too. ance sheetsandfinancialmuscleare vitallyimportant. dles intheroad towards the USDepartmentofDefense (DOD)’s targetof54GWoffshore windby2030,butthe the growth ofUSoffshore. Ofcourse,there are otherhur than faced by the first European investors in North Sea North in investors European first the by faced than the current mechanismoftaxcredits. Thetypeofinvestor the $1.9billion,845MWShepherds Flatwindfarmare Europelastonshoreprojectsin for MW 23 of average the try knows all about scale. The average size of new pro year. Consequently, investors in the United States are ac momentum, wecanexpecttoseetechnologythatbears needed todevelopoffshore windfarmswhere strong bal prospects forfinancingare brightening. projects, the financial leap of faith is much less daunting less much is faith of leap financial projects,the wind farms.AsNorthAmericanoffshore windgathers by the DOD would be huge. But then the US wind indus jects installed in 2012 was well over 100 MW,dwarfing 100 over well was 2012 in installed jects little resemblance in1991.We toVindeby willalsosee large playersseekingtooffset sizeabletaxliabilitiesunder There isnoquestionthatthescaleofinvestmentneed For USinvestorscomfortablewithgiantonshore Furthermore, theUSmarketstructure isdominatedby ■ Utilityequity ■ Otherequity ■ MFOorECAprojectfinance ■ Commercialprojectfinance E-Mail: [email protected] Phone: +17037958103 Strategy &PolicyStudies Craig Houston DNV GLEXPERT: CG

€1,300 Butendiek

m m 25 ------

10 12 14 16 4 2 0 6 8

Cumulative CapEx from the start to 2011 in billions of euros operations

With experience gained over almost three decades, GL Garrad Hassan has an unsurpassed technical under- standing of renewable energy technologies, projects and markets. The maintenance and optimisation of turbines and farms are key to the ongoing financial success of a project. GL Garrad Hassan is a pioneer of many of these services. Photo: inakiantonana | iStockphoto

26 energıze renewables 01/2013 27 operations maintenance

Who Will Win the Service Battle?

Although the revenues from service contracts Following bumper are growing in importance everywhere with years for wind an expanding fleet of installed turbines, the US installation in the stands apart from other national markets due to its sheer US, the fight to scale. There are currently 45,000 installed machines and the dominate the market for O&M is anticipated to reach six billion US dollars operations and a year by 2025. maintenance (O&M) It is not only the size of the O&M market that stands market is reshaping out. As is widely accepted in many other industries, provid- the North American ing after-sales services can be seriously good business. For wind industry manufacturers of products such as automobiles and medical equipment, after-sales activity accounts for a disproportion- ate share of profits. A study by Deloitte of 120 manufactur- ers from a range of industries found that after-sales services accounted for 26 per cent of revenues, but 46 per cent of profits. Unlike in many European countries where turbine manufacturers are pre-eminent, O&M in the US is provided by a diverse mix of firms.

Hunger for Hardware

In the heat of the wind farm construction boom of the last decade – with more than 13 gigawatts of new capacity add- ed last year alone – turbine makers neglected the service market in favour of meeting the hunger for hardware. But recent weaker demand and a global oversupply of turbines has seen them reappraise the value of ABSTRACT O&M as a steady source of revenue. Re- Service. During the US wind O&M is as a turning to the market, they are finding turbine construction boom, steady source that things have changed in their ab- manufacturers neglected of revenue. the operations and sence. maintenance business While the manufacturers’ backs Other providers have since were turned, a crop of new firms occupied that market segment emerged offering service contracts to

28 energıze renewables 01/2013

Photo: Alvera | Dreamstime.com Some haveevengoneasfartoextendtheirservice er, themanufacturers holdthetechnologycards. ISPsare al of lovewithO&Minthefirstplace. owners, manufacturers chal facesomedauntinginternal other owners. enced anddiverseenoughtooffer adegree ofchoicethat ers (ISPs)–manyofwhichare regional orlocal–are experi selling “powerbythehour”rather thanequipment. ship oftheenginesattachedtotheir customers’aircraft and support theirproducts outsideofthewarrantyperiod,some global manufacturers maystruggletomatch.Atthesame than everbefore. Backingupawarrantylastingtenyearsor the companyahugedataresource todrawonwhendesign them torespond quicklyandavoidfailures aswellgiving time, frustratedbymanufacturers’ apparent unwillingnessto formance of its global fleet of aero engines 24/7, allowing 24/7, aero engines of fleet global its of formance US project owners. Now,providprojectowners. service US independent these value of intellectual property. Rolls-Royce monitorstheper yielded valuableexperienceincontrolling operationalcosts. ness model,are offering newturbineswithlongerwarranties maintenance market.Aero enginecompaniesalsoblurthe sharing about are increasingly cagey they that readyfinding mean feat,andisprobably amongthereasons theyfellout no is broken ones fixing of task tricky the for turbines new wind farmownershavetakenontheirownO&M.Thishas ing newproducts orupdatingoldones.Thisvastknowledge information withnew-foundcompetitors. boundary betweenproduct andservicebyretaining owner base, growing daily, servestodissuadeISPsfrom enteringthe lenges. Re-toolingacompanygeared uptobuildandsell The jet engine business provides a prime example of theprovidesof business example engine prime jet a The Alongside external competitionfromAlongside external ISPsandhands-on Wind turbinemakers,whilestopping shortofthisbusi Wind But, inasectorwhere knowledgeis(quiteliterally)pow ------costs, forafee,reduces riskbutmayhandthemanufacturer cent years,butthefactthatlong-termservicecontractsare other data-drivenpreventative maintenancetechniquesto any future benefit from improved O&M techniques. A do-it- A techniques. from improved O&M futurebenefit any ability anddrivedowncost,toeveryone’s benefit. accurately predict turbinebehaviour. Betterunderstandingof and analysis Scada in growingconfidence at hints available scale ISPssimplydonothave. service contractspresent somethingofadilemma.Fixing This article was first published in Windpower Monthly(July2013) This articlewasfirstpublishedin yourself approach or a flexible contract with an ISP is riskier is ISP an with contract flexible a approachor yourself turbineO&McostsintheUSmayhaverisenre Wind nimble firms of all types to innovate and bring forward bring new and innovate to types all of firms nimble small- that something heft, financial serious moredemands wits, thestakescouldnotbehigher. ways ofdoingthingsisclear–butintheimpendingbattle wind farmowners’response tothisdilemma.Thescopefor what ishappeninginsideaturbinepromises toimprove reli but allowsownerstoshare insavingsifcostsfall.Thefuture Long-Term ServiceContracts landscape oftheUSwindindustrywillbedeterminedby For wind farm owners, however,owners, farm fixed-price wind long-term For E-Mail: [email protected] Phone: +441179729878 Strategy &PolicyStudies Oscar Fitch-Roy DNV GLEXPERT: O&M isanticipatedtoreach 45,000 machines $6 billionayearby2025 installed sofar

OFR

29 - - operations structures

The support structure for an offshore wind tur- signed to support what is now the biggest example of rotat- bine is a significant contributor to the total pro- ing machinery the world has ever seen, operating in some of ject cost of an offshore wind farm, typically con- the harshest environmental conditions the planet has to of- tributing up to 30 per cent to the overall capital expenditures fer. With billions of pounds of infrastructure at stake, struc- (CAPEX). Optimisation and cost savings in the areas of sup- tural integrity is paramount. But with the COE issue ever- port structure design, fabrication and installation may there- present, over-design is equally to be avoided. Engineering fore yield sizeable reductions in the overall cost of energy innovation may yet hold the key to resolving this tension. (COE) for offshore wind – a key metric in the long-term vi- A cursory assessment may lead one to think that the ability of the industry. Commercial-scale offshore wind farms traditional oil and gas sector has already addressed all of may eventually contain hundreds of individual structures, de- the major design challenges faced by the offshore wind in-

Jacket. Optimising the design, fabrication and installation of the support structures can reduce the capital expenditures.

Figure 1. Integrated numerical model of an offshore wind turbine.

30 energıze renewables Offshore Wind – Onboard Intelligence

The cost of offshore wind energy must come down to maintain public and government support. High-volume production and improved structural engineering, combined with advanced numerical modelling and robust turbine control algorithms harbour great potential

dustry today. Indeed, most of the body of knowledge and 1 0.9 experience relied on by the offshore wind structural de- 0.8 ■ Fully integrated signer has been derived directly from the pioneering work 0.7 ■ Fully integrated with advanced control 0.6 of oil and gas colleagues over many decades. Clearly, it is 0.5 good practice for the offshore wind industry to rely on and 0.4 Cost fraction draw from such expertise – few emerging industries have 0.3 0.2 the time required or the need to re-invent the wheel. 0.1

[normalised to fully integrated jacket cost] [normalised to fully integrated jacket 0 Nevertheless, while rightly acknowledging a debt to Fabrication Forging Casting Overall cost

these traditional offshore sectors and seeking to exploit Figure 2. Normalised cost comparison. Advanced vs what is held in common, it is important also to keep sight “standard” turbine control. of the key differentiators between the technologies. For ex- ample, offshore wind turbines tend to be unmanned struc- tures operating in relatively shallow waters, with their de- For the wind turbine, things are a little more complex. sign driven by fatigue loading. An offshore wind turbine Onboard control algorithms process measured data that support structure generally experiences a much greater pro- come from sensors distributed within the turbine, then portion of loading from the wind compared to more tra- make real-time changes to blade pitch and rotor speed ditional oil and gas structures. Furthermore, the offshore which, in turn, further modify the forces on the structure. wind turbine and support structure will typically display This feedback arrangement can be used to good effect to greater dynamic response owing to high levels of structur- regulate the energy captured by a wind turbine when sub- al flexibility, and more non-linear response, due primarily to jected to turbulent wind field conditions. And, just as sig- the nature of the aerodynamic loading on the rotor blades nificantly, it is used to mitigate damaging loading of the and the action of the turbine’s onboard control systems. structural components. An analogy is found in the difference between a punch- Cerebral structures bag and a professional boxer. The One of the most interesting differences between traditional ABSTRACT former doesn’t know when it has

oil and gas and offshore wind structures is the fact that the Structural designers face the been hit, and even if it did it could latter has a brain. The more traditional structure will be challenge of ensuring structural not do anything to change the fact. integrity while minimising cost described as exhibiting “passive” response – a large wave Not so the boxer, who has learnt Control algorithms optimise hits it and Newton’s laws tell us all we need to know about energy capture while minimising to duck and defend – to display fatigue and extreme loading

Photo: alpha ventus how the structure reacts. Simple cause and effect. “active” response. In other

01/2013 31 operations structures

words, an oil rig may be bigger and stronger, but an 1.0e +14 ■ Integrated analysis offshore wind turbine has the potential to “box clever”. ■ Integrated analysis with advanced control )s] 2 1.0e +13 Reducing the Cost ) (N/m 2 Which is good news for offshore wind structural designers 1.0e +12 facing the dual challenge of ensuring structural integrity

while minimising cost. GL Garrad Hassan engineers have Auto spectral density 1.0e +11

been at the forefront of numerical modelling of, and control [CJ5 mbr115 insp 1][(N/m algorithm design for, offshore wind turbines stretching back to the very inception of the industry. In this time GL Garrad 1.0e +10 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 Hassan has developed sophisticated time domain simula- Frequency [1/s] tion tools which are able to describe the complex interac- Figure 4. Auto-spectral density of the nominal stress time tion between the behaviour of the wind turbine and that of history for the saddle inspection point. The 0P and 3P con- the offshore structure supporting it. These models take ac- tributions are greatly reduced by the advanced IPC control. count of the combined wind and wave loading experienced by the integrated system and the details of its response. algorithm design targeted at reducing the fatigue loading Armed with such simulation capability, GL Garrad Has- imposed upon an offshore “jacket”-type structure by the san control engineers are able to design and tune control wind turbine. The control algorithm design incorporated algorithms which simultaneously target optimal energy cap- nacelle acceleration feedback and individual pitch control ture of the turbine while minimising fatigue and extreme (IPC) to achieve the fatigue load reduction. Nacelle acceler- loading of its support structure. Given that the majority of ation feedback introduces a collective pitch response out of cyclic loading typically comes from the turbine rather than phase with the tower motion to introduce additional tower the waves, the onboard control system has great potential fore-aft damping during turbine operation. to reduce the overall loading envelope of the structure, and 1P and 2P IPC loops modulate individual pitch demands hence its cost. A recent study by GL Garrad Hassan assessed at once and twice per rotor revolution respectively in re- the benefit available through the use of advanced control sponse to blade root load input signals. One of the effects of the 2P IPC action is to reduce the torsional fatigue loading transferred to the jacket support structure. Figure 1 provides 10 5 a graphic of a generic 5 megawatt-turbine on a jacket sup-

5 port structure in circa 40 metres water depth. Assuming a 0 set of realistic external site conditions, two jackets were de- 0 − 5 signed: one using the advanced control features described above and one without. In this particular example the sup- − 5 −10 Inspection point 1, crown Inspection point 1, Inspection point 1, saddle Inspection point 1, Nominal joint stress [MPa] Nominal joint stress [MPa] Nominal joint stress [MPa] port structure cost reduction resulting from the advanced

−10 −15 control strategy was of the order of 10 per cent, see Figure 2. 0 100 200 300 400 500 600 0 100 200 300 400 500 600 Time [s] Time [s] The principal reason for the cost reduction was the abil- ■ Integrated analysis ■ Integrated analysis with advanced control ity of the 2P IPC control to reduce the torsional loading

Figure 3. Time history analysis of the nominal stresses calculated at transmitted from the wind turbine tower base into the jack- two inspection points (saddle and crown) at critical joint locations. et sub-structure. Figure 3 gives an example of stress time

32 energıze renewables Design. Embracing innovation will help strengthen the industry.

histories in critical joint “hot-spots” of the jacket, for the Of course, it would be remiss to present such control two control strategies. Figure 4 shows the same hot spot innovation as a panacea for offshore wind structural design stresses in spectral format. It is clear that the use of the – many limitations do exist. An offshore wind turbine con- advanced control has removed the very large load cycles trol system can do little to mitigate breaking-wave loading evident in the baseline time history, hence reducing the fa- on an offshore structure located in a shallow water site, or tigue damage in the critical joints. ice loading in the Baltic or the Great Lakes. Likewise, parallel avenues of innovation must continue Clever but Not Omnipotent to be pursued. Our understanding and modelling of the GL Garrad Hassan continues to research the application turbine, the sub-structure and the environment in which of advanced numerical modelling and robust control sys- it operates (wind, sea and soil) will continue to improve. tem design to improve the design of offshore wind support High-volume fabrication techniques will be required to structures. As well as the study above, encouragement has bring down cost. Ultrasonic peening techniques may offer also been found from early-stage research into the relaxa- vastly improved material fatigue behaviour. Probabilistic tion of wind turbine frequency constraints and the applica- design methods will help reduce conservatism in structur- tion of forward-looking LIDAR. Indications to date are that, al design. Contracting arrangements will evolve to more with careful design and a willingness on the part of the in- efficiently leverage the technically optimal solutions on dustry to innovate, such advanced control design features offer, not just the solution favoured by procurement de- have a significant role to play in delivering structural integ- partments. rity and reduced cost of energy for offshore wind. Today, we cannot but acknowledge that the cost of off- shore wind energy is higher than society would like it to be.

Quantity. High- But we remain encouraged that our industry’s ability to in- volume fabrication novate and improve is as great as it has ever been. GMC will cut costs.

DNV GL EXPERT: Graeme McCann Head of Loads Analysis, Turbine Engineering Support Phone: +44 117 972 9937

Photos: alpha ventus E-Mail: [email protected]

01/2013 33 operations misalignment detection

Keeping Things Straight

Offshore wind turbine towers and their foundations are exposed to enormous cyclical forces with potentially damag- ing long-term effects, such as tower misalignment. GL Garrad Hassan helps Initial state customers monitor tower inclination

Seafloor

It is a perfectly plausible scenario: a structure 5

stuck in a sandy sea bottom and exposed to 0 Tower inclina- cyc­lical wind, tidal and wave forces for years -5 tion

after 1 million may eventually wiggle itself free, or at least lose its firm -10 load cycles footing and begin to lean. Depth below seafloor [m] -15 A wind turbine with a leaning tower is exposed to M [unit – MNm] after 1,000 load cycles -20 stronger wear and tear of bearings and gears. That is pre- after applying the mean load, 30 MNm, and 2 load cycles cisely what owners and developers of offshore wind farms -25

-30 ABSTRACT in the North Sea are afraid of. In fact, observations in some existing -35 Various approaches work together 0 1 2 3 4 to establish a more solid scientific offshore wind farms have revealed Horizontal shifting [cm] basis for future wind turbine unexpected settling and displace- foundation engineering ment processes affecting the grout- Simulated load: GL Garrad Hassan offers a new tower misalignment ed connection between the under- 20 detection service water structure and the tower. 30

The Leaning Tower Syndrome M [unit – MNm] t

But offshore wind energy is a relatively young technology Forecast. Computer that hasn’t been around long enough to gather long-term simulation confirms the basic experience with this phenomenon. And the North Sea’s fitness of a model for long-term deformation predictions, in sandy bottom is a tricky basis for wind turbine foundations: this case the increase of tower the combination of sand, water and cyclical loads is a real inclination proportionate to

challenge to engineers trying to predict the long-term be- Nors/Depositphotos; Graphics: Fraunhofer Institute Photo: Tracy the load cycle.

34 energıze renewables haviour of wind turbines and the soils they are anchored in. eration sensors in the nacelle. These devices are normally So how can operators know whether their wind farms are part of the wind turbine control system. They measure the in danger of the “Pisa syndrome”? dynamic behaviour of the structure and shut the turbine There are various approaches to improving the prediction down under certain conditions. GL Garrad Hassan’s system of soil and foundation behaviour under cyclical loads, and to is portable, standalone and uses its own accelerometers to minimising the leaning-tower effect. They all work together determine the tower inclination. The results of the assess- to establish a more solid scientific basis for future wind tur- ment are presented to the customer in an inspection report. bine foundation engineering. There are several alternative delivery models for this The first approach is to choose the tower foundation tower inclination measurement service: GL Garrad Hassan type that is best suited for the tower height, water depth can perform a periodic inspection using its mobile sys- and seafloor conditions at a given site, i.e. a gravity, mono- tem. The licence for this service is also available for main- pile, tripod or jacket foundation, or a combination of these tenance companies who can run an automated analysis concepts. Tripod and jacket foundations rely on technology using the software provided. Customers­ who wish to im- borrowed from oil and gas platforms, but the changing wind plement a continuous vertical tower alignment monitoring loads and wind directions acting on wind turbines, the lever programme may purchase the hardware­ for permanent in- action on the tall towers and the vibrations caused by the stallation. And finally, GL Garrad Hassan offers its concept 5 interplay of forces complicate the load situation significantly. to manufacturers of offshore wind turbines­ as a service or

0 The second approach is the thorough study of the me- maintenance test that may be integrated­ into the turbine

-5 chanics involved, applying finite-element computer modelling control system.

-10 techniques and using lab simulations on scale models to ana- lyse and predict the long-term interaction between the turbine The Early Bird -15 foundation and the surrounding soil. Several institutes have Every wind turbine owner wants to protect its investment, -20 conducted such studies and provided valuable information. and every operator wants to ensure the maximal availabil- -25 The third approach consists in the systematic collection ity of every single machine throughout its 20-year service -30 of on-site data on the mechanical behaviour of specific off- life. Detecting potential problems as early as possible helps

-35 shore wind turbine towers and foundations so the operator avoid costly breakdowns and repairs and lengthy downtime. 0 1 2 3 4 can take preventative action when a tower starts leaning. Furthermore, the North Sea is a highly sensitive natural envi- ronment, and parts of its German coastal region form a con- An Ounce of Prevention servation area where a wind turbine average would result in GL Garrad Hassan has been working with research a major environmental disaster. GL Garrad Hassan’s tower 20 30 institutes and other stakeholders for years to gather the misalignment detection service is a simple procedure that required expertise and provide effective assistance for delivers accurate results, thereby contributing to high opera- t the prevention of problems caused by leaning wind tur- tional efficiency and peace of mind. NH bine towers. The result is a new service offering: a patent- ed method that uses existing, “on-board” equipment to measure and assess the wind turbine tower loading and DNV GL EXPERT: alignment. Nils Heining Acoustics & Inspections The method, which is suitable for both onshore and Phone: +49 48 56 901 59 offshore wind turbines, relies on data gathered by accel- E-Mail: [email protected]

01/2013 35 36 energıze renewables certification

Certification of wind farms, turbines and their components is state of the art and a must around the world. GL Renewables Certification offers project and type certification. Photo: inakiantonana | iStockphoto

01/2013 37 certification guidelines

Minimising Risks, Earning Trust

Mike Wöbbeking, GL Renewables Certification’s Head of Certification Body, about guideline developments and offshore innovations

The offshore wind energy market is developing MIKE WÖBBEKING: We revise our guidelines every five to at a breathtaking speed. Turbines, substations seven years to account for the latest technical develop- and offshore sites are increasing in size and ments and processes. The offshore wind industry is devel- are being placed in more challenging environments. There- oping extremely rapidly. Turbines continue to increase in fore the industry must remain vigilant and work to stand- size, new tower designs are introduced, and installations ards that keep pace with the rapid developments in tech- advance into deeper waters. The size of wind farms increas- nology and practice. To ensure that offshore wind farms es as well. We are involved in over 50 offshore wind farm ABSTRACT are built to standards which are state of projects. The new guideline incorporates all the additional the art, GL Renewables Certification (GL experience we have gained over the years. GL RC has published a new issue of its offshore RC) recently published its new “Guide- wind turbine certification line for the Certification of Offshore ENERGIZE: What in particular is new? guideline The new version incorporates Wind Turbines, Edition 2012”. WÖBBEKING: The new guideline delivers a fully integrat- recent developments in ed design and analysis concept for offshore wind turbines, technology and standards ENERGIZE: GL RC has published a covering every aspect of development from the blade tip Certification and third-party assessment are prerequisites new certification guideline for through to the foundation and the power export cable. It for project approval, offshore wind turbines. What were reflects major developments such as increased turbine sizes, financing and insurance the reasons? deeper waters as well as load mitigation using advanced,

38 energıze renewables posing new challenges, for example with re- Released. gard to stability and mooring safety require- The new “Guideline ments. Similar structures are well known in the for the Certification of Offshore Wind offshore oil and gas industry but have to be Turbines, Edition 2012”. adapted for unmanned operation, installation

Confident. Mike Wöbbeking explains the of wind turbines and deployment in large numbers in wind revised guidelines. farms. We also developed and included options for risk- based certification of innovative designs. intelligent control systems. As a consequence, control sys- tem examination and testing are now part of the guideline. ENERGIZE: How does risk-based certification work in The new version also contains a number of innovative ana- practice? lytical methods for factors such as the effects of cyclic loads WÖBBEKING: Our method allows innovative concepts not on piles under compressive and tensile stresses. In addition, yet covered by existing guidelines to be included in the cer- the guideline addresses load stability and mooring safety tification process. In such a case the certification body must requirements for floating wind turbines. cooperate very closely with the designer and also the owner Another new element is floating wind turbines which of the innovative structure or component. Following the de- are planned for installation in several parts of the world, sign preview (called “Phase I”), in which the innovative Photo: Kimson1972 | Dreamstime.com

01/2013 39 certification guidelines Photo: Alpha-Ventus

Alpha Ventus. Commissioned in April 2010, the wind farm feeds an estimated 220 Gwh per year into Germany’s utility grid, enough to supply 50,000 households with electricity. In the harsh offshore environment, safety and long-term structural stability are core concerns.

design and possible challenges in terms of guidelines WÖBBEKING: All of GL Renewables Certification’s guide- are agreed, a preliminary analysis in qualitative terms (Phase lines and technical notes are discussed by our Wind and II) is performed. In this process the scope of the analysis is Marine Energy Committee prior to publication. The Com- first defined, whereupon the relevant hazards are identified mittee is composed of representatives of the relevant stake- applying a mutually agreed method, and ranked. Casualty holder groups, including public authorities, wind turbine scenarios are developed based on the ranked hazards for component manufacturers, engineering consultants, in- use in the quantitative analysis (Phase III). In the subsequent stitutes, universities, technical associations and insurance refinement and construction phase (Phase IV), the design re- companies. It is important for us to cooperate closely with quirements and risk mitigation measures resulting from the the industry in the development of our guidelines. analysis are implemented, analysed and tested. Then the sys- tem is commissioned and monitored during the installation ENERGIZE: Why is certification important, especially for (Phase V) and operation phase (Phase VI). offshore wind installations? WÖBBEKING: Minimising risks and earning the trust of in- ENERGIZE: How was the guideline developed? vestors, insurers, operators and authorities are the main WÖBBEKING: The guideline was originally compiled jointly purposes of third-party assessment as part of the certifica- by our own team and the Wind and Marine Energy Com- tion process. As wind turbines as well as wind farms con- mittee. In March 2011 we launched a new project to revise tinue to grow in size, winning the approval of financing the existing GL offshore guideline of 2005 to incorporate banks, insurance companies and the authorities depends new aspects and lessons learnt. All chapters and sections more than ever on successful reliability and safety assess- of the existing edition were reviewed and revised, and new ments of such products and projects. These assessments are information was adopted to account for new concepts, de- carried out along with the component type, turbine, and velopments and solutions in technology and certification. complete offshore wind farm certification process, evaluat- The rules were harmonised with other existing guidelines ing the reliability, safety, strength and fatigue properties of and standards and our own, revised onshore guideline the equipment to ensure safe operation. MD which had been released shortly before. About 60 engi- neers worked on the new guideline, which was finally pub- lished in December 2012. DNV GL EXPERT: Mike Wöbbeking Vice President GL Renewables Certification ENERGIZE: Who is the “Wind and Marine Energy Commit- Phone: +49 40 36149-3307 tee” involved in the development of the guideline? E-Mail: [email protected]

40 energıze renewables Selected Offshore Reference Projects

GL RC is involved in more than 50 offshore projects worldwide including:

Alpha Ventus Amrumbank West Baltic I Bard Offshore I Borkum Riffgrund I + II Dan Tysk Dudgeon EnBW Baltic 2 EnBW Hohe See FINO FINO 3 Global Tech I London Array Meerwind Northwind

To view a complete list of offshore reference projects, go to www.gl-group.com/ glrenewables.

Dan Tysk. The barge transporting the 3,000-tonne sub­ station to the wind farm is fitted with several air chambers that are partly filled

Photo: Vattenfall/Jorrit Lousberg Photo: Vattenfall/Jorrit with water.

01/2013 41 certification meerwind

Managing Risks of Offshore Wind Parks

The 288-megawatt offshore wind farm “Meerwind” is on course. GL Renewables Certification is playing an important role in making this project safe and reliable

The Meerwind offshore wind farm, consisting the wind turbines, the offshore substation as well as assets of the Meerwind Süd and Meerwind Ost sec- such as cabling within the wind farm are integral parts of tions, is located in the German Bight 23 kilo- the project certification process. Handling such a complex metres north of the island of Heligoland. When completed, assignment not only requires extensive knowledge and ex- the site will comprise 80 wind turbines, each with a rated perience but also excellent project management skills. power output of 3,6 megawatts. The turbines, which will be certified by GL Renewables Certification (GL RC), will Industry Best Practices be connected to an on-site transformer platform tied into “Meerwind successfully passed all three BSH releases. As a the shoreside grid. Meerwind will be one of the first opera- next step we will issue the project certificate as soon as all tional commercial offshore wind farm projects in German the turbines are in operation and assessments are finished waters and is to be completed by the end of 2013. successfully,” explains Robert Grohe, the responsible Pro- GL Renewables Certification was contracted as an in- ject Manager at GL Renewables Certification. “The project dependent, accredited certification body to certify the en- has been realised applying industry best practices, with spe- tire Meerwind project, including full third-party assessment cific improvements such as accounting for higher waves. and certification of everything from Furthermore, the installation phase was optimised by in- ABSTRACT site conditions and site-specific de- stalling monopoles and transition pieces in wintertime.” “Meerwind”, one of Germany’s first commercial sign through to surveillance of all im- GL RC is involved in the majority of all offshore pro- wind farms, will be commis- portant project stages. Manufactur- jects in Europe. With the rapid growth of the wind energy sioned early 2014 ing surveillance included inspection industry and the increasing size of onshore and offshore The entire project is certified by GL RC as an independent, of 51 different production facilities. wind farms, the financing banks, insurance companies and accredited certification About 120 GL experts are in- authorities insist on thorough reliability and safety assess- body

volved in this project. Apart from ments of these projects. These assessments are part of the Photos: WindMW

42 energıze renewables Manufacturing Process. Construc- tion with installa- tion of the first monopiles started in September 2012.

certification process for components, turbines and entire wind farms. Wind turbine certification in- cludes reliability, safety, strength and fatigue eval- uations to guarantee safe operation. Third-party assessment, a crucial aspect of the certification process, minimises risk and boosts the confidence of in- vestors, insurers, operators and authorities. Pro- ject certification by independent certification bodies is required by the German authorities for wind farms located in the German exclusive

economic zone (EEZ). MD

DNV GL EXPERT: Robert Grohe Concrete Structures and Geotechnics Phone: +49 40 36149-7055 E-Mail: [email protected]

North Sea. The location of “Meerwind” is one of the most promising in the emerging offshore wind business in Germany.

01/2013 43 certification carbon footprint

Reducing Your Carbon Footprint

A certified carbon footprint is by no means an attestation of environmental idealism. It contributes significantly to a company’s public and financial appeal

Trend. A credible carbon footprint report shows the com- mitment to re- duce greenhouse gas emissions (GHG).

Sustainability has entered the main stream. sation, measured in tonnes of CO2 equivalents as an ab- There is a general trend across all industries solute and relative value (e.g. per dwt, per product or per towards seeking competitive advantage by site square foot). To support carbon reduction initiatives, adopting a green business agenda. An improved “carbon GL Systems Certification is introducing a new service line footprint” is one of the key ingredients of a corporate an- based on the ISO 14064 standard, nual sustainability report, as it provides a quantified value ABSTRACT which specifies the principles and for a company’s environmental impact on for example cli- A well-designed organisational requirements for quantification and mate change. Especially in highly competitive markets, this carbon footprint inventory reporting of greenhouse gas emis- attracts investor capital indicator is today an important differentiator. sions. GL Systems Certification has The organisational carbon footprint reflects the total developed an effective There are several reasons for verification approach

amount of greenhouse gases (GHG) emitted by an organi- organisations to invest in carbon Photo: Auris | Dreamstime.com

44 energıze renewables measurement/management and reduction. These include investor transparency, client green goals, potential govern- mental and cost reduction pressure. A global survey con- ducted by the Harvard Business School in 2011 shows the increasing interest of investors in the greenhouse gas bal- ance of a company. Respondents showed that most par- ticipating investors view climate change issues as a material investment risk/opportunity across their organisation’s entire invest- ment portfolio. The fact that high-profile compa- 0.8 °C nies such as Wal-Mart and Apple have APPROXIMATE AMOUNT made attempts to not only reduce their OF GLOBAL WARMING own environmental impact, but those OVER THE LAST 130 of their suppliers, shows the significance YEARS of a carbon footprint compilation. In the UK, telecommunications giant BT has recently introduced a scheme to encourage their vendors to reduce carbon emissions during the production, delivery, use, and disposal of products and services supplied to BT. The new scheme has three expectations that vendors must adhere to. Initially, each vendor has to demonstrate that it has implemented a policy to address the challenge of climate change. Secondly, vendors should be actively measuring and reporting their carbon footprint. Lastly, a vendor must implement “challenging targets” to

Organisational Carbon Footprint Seven Stages of Analysis

Stage 1 Stage 2 Stage 3 Stage 4 Stage 5 Stage 6 Stage 7 Establish Establish Identify GHG sources Define Determine Third-party Report organisational operational (and sinks) for the quantification corporate carbon verification of carbon boundaries boundaries chosen scopes methodologies footprint carbon footprint footprint

01/2013 45 certification carbon footprint

reduce emissions and report on the progress. “A well- deadline for the first inventory was December 2012; inven- designed organisational carbon footprint inventory that tories must be updated every three years. delivers credible, transparent key performance indicators Likewise, greenhouse gas regulations are being re- will attract investor capital without revealing sensitive in- leased by the financial sector. By April 2013, all companies formation,” says Geraldine Findlay, Carbon Product Man- listed on the London Stock Exchange will be required to ager, GL Systems Certification. Furthermore, she adds, “car- submit annual sustainability reports including their carbon bon footprinting helps businesses by pinpoint- footprint in order to continue trading. It will be one of the ing the right areas for investment and hotspots first mainstream exchanges in the world to make reporting where reductions in carbon and costs can be mandatory as part of the UN’s Sustainable Stock Exchang- made. This can also include the entire supply es Initiative along with others from Johannesburg, Istanbul INFO. chain.” With environmental awareness and cli- and Mumbai. “It is highly advisable for organisations to in- Direct link to mate change high on the agenda of many gov- troduce carbon monitoring and management systems soon- GL’s Sustain- ability ernments, it is likely that organisational carbon er rather than later to avoid having to do so under pressure and Carbon footprint reporting and other, similar environ- at a later time,” Geraldine Findlay points out. Services mental regulations and initiatives will potential- webpages. ly become legally binding in the future. Getting a Head Start with GL For example, in the United Kingdom in In addition to the organisational carbon analysis, GL’s Car- 2010 the UK government launched the Carbon Reduction bon Footprint Service also includes seminars and training. Commitment (CRC). This is a mandatory reporting pro- The process of the carbon footprint inventory consists of gramme aimed at large non-energy-intensive companies to five stages, with an optional 6th stage of “third-party veri- incentivise them to reduce their greenhouse gas emissions. fication” and a further optional 7th stage of “reporting In France, the “Grenelle II” requires companies with 500+ carbon footprint” (see diagram). employees to calculate their GHG inventories according to First, the company defines the goals and boundaries modalities defined by a decree published in July 2011. The of the GHG inventory (steps 1–2). Once this is complete

GL Environmental Services

GL offers a range of sustainability and Windmade label verification For more information on these and carbon services, many of which can be Corporate social responsibility (CSR) other environmental services please combined and built upon to increase Clean development mechanism visit the GL Sustainability and Carbon corporate environmental awareness (CDM) and voluntary emission Services website: and introduce carbon management: reduction schemes (GS, VCS)

Organisational carbon footprint World commission on dams (WCD) WWW.GL-GROUP.COM > MARITIME >

Product carbon footprint and Water footprint services MANAGEMENT SYSTEMS CERTIFICATION >

lifecycle assessment Training courses SUSTAINABILITY AND CARBON SERVICES Photo: Monkey Business Images | Dreamstime.com

46 energıze renewables Seminars. Carbon footprint seminars can be booked online through GL Systems Certification (E-Mail: [email protected]). In addition, GL hosts a new type of conference called “Green Wednes- day”, where business professionals from different industries meet to share knowl- edge on green subjects such as CSR and the green supply chain.

the company experts collect the 93 % the ISO 14064 standard and is free of material misstate- SHARE OF GLOBAL relevant data and with this compile WARMINGS HEATING ments. Once the verification is complete the company can the greenhouse gas inventory (steps THE OCEANS publish its verified carbon footprint with confidence that it 3–5). In stage 6 the audit is undertak- will stand up to public scrutiny. en. During this stage, the GL auditors will “The carbon footprint helps to bring a different per- conduct on-site interviews, evidence checks spective to the business and strategic decisions,” concludes and recalculation of figures to ensure that the GHG inven- Geraldine Findlay. “Investment that leads to lower emis- tory is consistent, robust and in line with the ISO standard. sions will enhance cost efficiency and competitive advan- If the company wants to assure prior to the audit that tage. Avoiding this investment is tantamount to maintain- no material discrepancies are to be expected, it can ask ing an unnecessarily high carbon output, which will ulti- the auditors of GL Systems Certification to do a pre-audit mately drive up costs. Carbon accounting is going to be

(“readiness review”), in which a first check of the most im- an integral part of every corporate balance sheet.” GD portant parts of the inventory will be done. Another advan- tage of this is that it reduces the extent of the main audit. If during the audit non-conformities are identified, they DNV GL EXPERT: will be discussed with the client. Then, the audit report and Geraldine Findlay GL Systems Certification final verification statement will be created. In this it will be Phone: +49 40 36149-2492 stated if the GHG inventory of the company is in line with E-Mail: [email protected]

01/2013 47 oil&gasgl group’sxxxxxxxxxxxxxxxxxx renewables business segment projects in brief

GL RC CMS – New Guideline Released CEPRI Strategic Cooperation Agreement on PV Inverter Testing hamburg GL Renewables Certification has published its new “Guideline for china The China Electrical Power Re- grid adaptability testing, and power out- the Certification of Condition Monitor- search Institute (CEPRI) and GL Garrad put character testing. NESC operates ing Systems for Wind Turbines”. This Hassan have signed a memorandum of mobile PV testing platforms and is guideline was compiled in cooperation understanding (MOU) on strategic coop- charged with the development of with its Wind and Marine Energy Com- eration in the area of photovoltaic (PV) the test standard and PV power stations mittee and covers the most important inverter measurement and testing. The for China. requirements for the development, agreement will see CEPRI’s National Ener- The two parties have also agreed to installation and operation of condition gy Solar Center (NESC) and GL Garrad cooperate on client projects, where re- monitoring systems (CMS). “Currently Hassan cooperate in the field of grid-con- quested, maintain open communications almost all condition monitoring systems nected performance testing including on technical matters, and offer informa- are operating independently from the low-voltage ride-through testing, voltage/ tion and advice on the development of control system and the drive train is frequency response testing, active/reac- European, Chinese and international monitored almost exclusively,“ says Dr tive control testing, power quality testing, standards and directives. Karl Steingroever, GL RC’s expert for CMS. “Future condition monitoring systems will be partly or fully integrat- ed into the control system and include the monitoring of the entire wind tur- bine. In this context the definition of interfaces between the systems is play- Photovoltaics. ing a major role.” A solar power plant on a hill of Jinzhou, DNV GL EXPERT: Karl Steingroever, GL Renewables Certification north-eastern China. Phone: +49 40 36149-7440

E-Mail: [email protected] | Dreamstime.com Photos: Hsc/Mike Watson/Vwvwvwvwv

GL GARRAD HASSAN Guide for Landmark Offshore Wind Operations and Maintenance

bristol GL Garrad Hassan recently published Phillips, Head of Strategy and Policy at GL anyone with an interest in a major new UK the “Guide to Offshore Wind Operations and Garrad Hassan. “From the likely scale of the industry.” The UK offshore wind O&M servic- Maintenance”, which was jointly funded by future market to logistical strategies for ac- es are expected to grow to £1.2 billion per The Crown Estate and Scottish Enterprise, and cessing turbines at sea and approaches to year by 2020 and continue on as the offshore gives a clear account of the relevant concepts, contracting, the guide is essential reading for sector expands. O&M expenditures make up trends and players in the offshore wind op- some 25 per cent of the total kilowatt-hour erations and maintenance sector. Guide. costs over the entire life of a turbine, but “This document gives new entrants to the Covering UK represent a much lower share than conven- sector everything they need to develop a offshore tional thermal power stations which are reli- picture of offshore wind O&M,” says Joe wind O&M. ant on a fuel source.

48 energıze renewables Rules for Certification and Construction. Our latest brochures, rules and guidelines are available on request. Order forms are available on the Internet: www.gl-group.com > Rules & Guidelines

GL GARRAD HASSAN Accelerating GL RC Tropical Cyclones – new Technical Note for the Cost Reductions Certification of Wind Turbines

bristol An ambitious project to bring fresh china GL RC has published its new thinking to the design of offshore wind tur- “Technical Note for the Certification of bines has recently been launched by GL Gar- Wind Turbines for Tropical Cyclones”, a rad Hassan. Adopting an open-minded ap- supplement to GL RC’s Guidelines for the proach, Project FORCE (turbine optimisation Certification of Wind Turbines and ad- FOr Reduced Cost of Energy) will focus GL dresses the question how cyclones are Garrad Hassan engineering expertise on the influencing wind turbine designs. design of low cost offshore wind turbines in An increasing number of onshore the seven- to ten-megawatt range. New tech- and offshore wind parks are proposed in nologies to be considered include rotor de- cyclone-affected areas Properly designed sign and innovative control systems which wind parks should be able to withstand Cyclone. Strong weather reduce structural loads at the same time as the cyclones that are likely to affect conditions threaten wind parks. regulating turbine power. them within their lifetime. Photo: NASA The UK government’s Offshore Wind Cost Recent tropical cyclones such as ty- its new Technical Note, GL RC provides Reduction Task Force showed that offshore phoon Usagi, which hit the Honghaiwan detailed information to wind turbine wind can achieve a levelised cost of energy of Wind Farm in coastal Shanwei City, designers and manufacturers on this £100 per megawatt-hour by 2020 and The Guangdong, demonstrated the potential important issue. Crown Estate’s Cost Reduction Pathways pro- of extreme weather to impact upon wind The Technical Note can optionally be ject identified “echnology acceleration” as park sites. The lack of clear guidance for applied within the certification proce- one route to achieving significant cost reduc- categorising the risk a site faces of being dure and defines the additional design tions. GL Garrad Hassan’s Project FORCE ad- hit by a cyclone and the extreme variabil- requirements to be considered for type dresses the challenge of cost reduction, focus- ity with which such storms effect wind and project certification as well as re- ing in particular on the use of new and inno- farm structures, mean that developers quirements for site assessment. vative technology in offshore applications. are left with the uncertainty as to the The Technical Note can be ordered: The results of the project will be made avail- fitness of their developments to deal www.gl-group.com/en/certification/ able to the industry later this year. with extreme weather conditions. With renewables/CertificationGuidelines.php

GL RC Setting the Standard for Training

hamburg GL RC certifies training providers offshore industry is highlighted by figures ployed in offshore wind will rise to 170,000 according to its standards, which set out the recently announced by the European Wind in 2020, a fivefold increase from 2010. “The fundamental prerequisites for efficient Energy Association (EWEA). The association demand for safety training is increasing with training, such as proper organisation of the estimates that the number of people em- the expansion of the offshore wind indus- training course, careful documentation and try,” confirms Reinhold Heller, Expert for high-quality teaching equipment and mate- Boom. Certification of Training Systems at GL RC.

rials. The “Certification of Training Pro- Demand DNV GL EXPERT: grammes and Training Systems in the Re- for safety Reinhold Heller, GL Renewables Certification newable Energy Industry” has recently been training is Phone: +49 40 36149 7931 updated. The importance of training in the rising. E-Mail: [email protected]

01/2013 49 Photo: Mike Watson | Dreamstime.com Photo: Mike Watson service dates at a glance

Conferences & Fairs 2014 IMPRINT

energize renewables, issue no. 01/2013, November 2013 Frequency MARCH energize renewables is published twice 10. – 13.03.2014 a year Published by DNV GL, Hamburg EWEA Editorial Director Olaf Mager (OM), Networking. Europe's Communications Managing Editor Steffi Barcelona, Spain premier wind energy confer- www.ewea.org ence and exhibition. Gößling (SGG) Authors of this issue Volker Bertram (VB), Monika Dippel (MD), APRIL Geraldine Findlay (GF), Oscar Fitch-Roy (OFR), Nils Heining (NH), Craig Houston 02. – 3.04.2014 (CH), Jörn Iken (JI), Graeme McCann Hamburg Offshore Wind Market. Experts (GMC), Jeremy Parkes (JP), Paul Reynolds Hamburg, Germany discuss the (PR) Cover photo Volker Schlichting/ perspectives. Depositphoto.com Design and production MAY printprojekt, Schulterblatt 58, 20357 05. – 08.05.2014 Hamburg, Germany Layout and prepress AWEA Las Vegas. Lohrengel Mediendesign Translations The nexus of wind energy Eugen Klaußner, Andreas Kühner Printed Las Vegas, USA professionals at Mandalay by Media Cologne Kommunikationsmedien www.windpowerexpo.org Bay Convention Center. GmbH, Luxemburger Straße 96, 50354 Hürth, Germany Reprint © DNV GL 2013. SEPTEMBER Reprinting permitted on explicit request – 23. – 26.09.2014 copy requested. All information is correct WindEnergy Hamburg Hamburg. The new to the best of our knowledge. Contributions event just after the Hamburg, Germany leading maritime by external authors do not necessarily www.windenergyhamburg.com fair SMM. reflect the views of the editors or of Germanischer Lloyd Enquiries to DNV GL, OCTOBER Communications, Brooktorkai 18, 20457 Hamburg, Germany, Phone: +49 40 36149- October 2014 7959, Fax: +49 40 36149-250, E-Mail: China Wind Power China. Huge [email protected] Beijing (tbc) investments in n/a Wind power. Subscription service: For address changes and orders please send an NOVEMBER e-mail to [email protected]

11. – 13.11.2014

Renewable UK Insights. Manchester, UK Europe’s most improtant market

www.renewableuk.com for wind energy van den Dries Photography/Depositphotos.com; pdphoto.org; WindEnergy Beggerly; renewableuk.com Hamburg; Brian Jeffery Photos: Ewea; Teun

50 energıze renewables Training

TRAINING COURSES – DATES 2013/2014

Wind Farm Design & Wind Farm Design & Verifying and Optimising Introduction to WindFarmer WindFarmer (Advanced) Wind Power Performance 27 Nov. 2013 São Paulo, BR 25 – 26 Nov. 2013 Chennai, IND 20 – 21 Nov. 2013 Mexico City, MEX Advanced Use of WindFarmer 27 – 28 Nov. 2013 Arnhem, NL Tidal Bladed Software 15 – 16 Jan. 2014 Bristol, UK 26 – 28 Nov. 2013 Bristol, UK 13 Feb. 2014 Bristol, UK

For more information on these courses, see: www.gl-garradhassan.com/training GL Garrad Hassan 45 MainStreet gl-garradhassan.com North America Region Suite 302 E-Mail: info.usa@ Fax: +16039248805 Phone: +16039248800 USA Peterborough, NH03458

CEMEA gl-garradhassan.com Germany 26129 Oldenburg Region Marie-Curie-Straße 1 E-Mail: info@ Fax: +4944136116889 Phone: +4944136116880 Peterborough

UKIIS gl-garradhassan.com Region Silverthorne Lane St Vincent’s Works E-Mail: Fax: +441179729901 Phone: +441179729900 UK Bristol BS20QD info@ Zaragoza

Bristol

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Certification GL Renewables gl-group.com Germany 20457 Hamburg Brooktorkai 18 E-Mail: Fax: +494036149-1720 Phone: +494036149-0 glrenewables@

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