Ballast Nedam Offshore-On the-move

On the move

From design to maintenance: an all-in approach

Heavy lift vessel Svanen: the jewel in the crown

Drilled concrete monopiles

With contributions by Göran Loman and Gijs van Kuik

Ballast Nedam Offshore

Ballast Nedam Offshore On the Move

The offshore wind energy market is exciting and highly dynamic. Financial developments, technological possibilities and the political climate together play a significant role in the construction of wind turbine farms. Over the next few years, the northern European wind energy market will witness the completion of many new projects. Ballast Nedam, a Dutch company of international acclaim has been a civil and marine contractor for more than a century, while Ballast Nedam Offshore has been operating in the European market for well over ten years.

At the time, the establishment of Ballast Nedam Offshore was the direct result of initiatives taken by Ballast Nedam to promote sustainability through practical and feasible applications and solutions. Its investments in offshore wind energy form part of a wide range of activities focusing on sustainable energy concepts for the benefit of civil engineering projects, mobility and real estate.

Ballast Nedam Offshore offers its clients the convenience of a one-stop shop, culminating in the turn-key provision of a foundation. We also offer assistance with project development, including financing and permits, design, construction and ongoing maintenance. To be able to offer this comprehensive package, Ballast Nedam Offshore closely cooperates with other Ballast Nedam companies, such as Ballast Nedam Engineering, Ballast Nedam Funderingstechnieken (Foundation Technologies), Ballast Nedam Beheer (Operations and Maintenance) and Ballast Nedam Concessies (Concessions). Since 2008 we have offered our clients one clear point of contact for the construction of offshore wind farms: Ballast Nedam Offshore.

We welcome clients at any point in the chain. We can help them arrange the necessary funding, we can carry out maintenance work (also with respect to wind farms built by other firms) and we rent out our heavy lift vessel (HLV) ‘Svanen’. In short: we do it all. As yet, Ballast Nedam Offshore is the one and only European contractor to combine all the activities necessary for the construction of offshore foundations.

In this magazine we describe Ballast Nedam Offshore’s current position and expertise, and present our goals for the future. In a European energy market where offshore wind energy is expected to be a significant force by 2020, we are more than ready to apply our broad experience in this area and create new successes; for ourselves, but chiefly for our partners and clients, long-standing and new.

Marcel van BergenDirector Ballast Nedam Offshore

Preface

Table of ContentsInterview with Director Marcel van Bergen and Commercial Manager Edwin van de Brug 4 Göran Loman, Project Manager at Vattenfall: Kriegers Flak Foundation Study 7 Heavy lift vessel Svanen: ready to handle the next generation of monopiles 8 Innovation: the prefabricated drilled concrete monopile & one-lift concept 10‘Ideas simply present themselves, usually on a lazy Sunday afternoon’ 12 Collaboration: complete and integrated solutions for offshore wind farms 14Director Marcel van Bergen: ‘Quality through cooperation in the chain’ 16The road to a certified design 18 Low-maintenance offshore wind farms 22History focus 24Gijs van Kuik (EAWE): ‘The Netherlands has got exactly what it takes’ 26

2009Offshore wind farms: Offshore Windpark Egmond aan Zee, Princess Amalia Wind Farm Total number of wind turbines: 96, each with a capacity of 2-3 megawatts (MW)Combined capacity: 228 MW CO2 reduction: 316,000 tonnes per annum North Sea surface area: 44 km2 Enough power for: 225,000 households

2020Total number of wind turbines: 1,000 – 1,500 Combined capacity: 6,000 MW CO2 reduction: 10 million tonnes per annumNorth Sea surface area: 1,000 km2 Enough power for: 25 per cent of all Dutch households

OFFSHOre WinD enerGy in THe neTHerLanDSCurrent situation and objectives for 2020

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An interview with director Marcel van Bergen and commercial manager Edwin van de Brug shows Ballast Nedam Offshore as a reliable and innovative company with a broad compass of services and products. Although the official trade name ‘Ballast Nedam Offshore’ only entered the market last year, the company has developed a wide-ranging experience in the construction of solid foundations, both on land and at sea.

Ballast Nedam carried out its first projects as far back as 1877. More recent projects include the Zeeland Bridge in the Netherlands, the King Fahd Causeway linking Saudi Arabia to Bahrain, the Storebaelt Bridge in Denmark and the Confederation Bridge in Canada – all of which are not only intrinsically challenging and innovative, but have international appeal as well. It was during the process of constructing bridges that the idea for the heavy lift vessel Svanen was born: the Ballast Nedam Offshore flagship. Edwin van de Brug takes up the story: ‘Ballast Nedam offers significant flexibility for innovations. Of course, not every new plan proves to be a success, but you need to have the guts to initiate it. This place truly is a breeding ground for new ideas. At the end of the 1980s, for example, we said to ourselves that what we really needed was a specific and highly specialised heavy lift vessel for the construction of the Storebaelt Bridge. And look at us now. We’ve been working with the HLV Svanen very successfully since 1991.’

Stable, reliable, safe and dependableWhere other operators use jack-ups when laying foundations, making them larger and higher to create a stable basis, Ballast Nedam started thinking ‘outside the box’. The company searched for a new solution, and found one. Thanks to its dimensions, its gross weight (over 13,000 tonnes) and its catamaran shape, the HLV Svanen has incredible stability. Indeed, no ballast is required when hoisting loads, and the calmer sea between the ship’s two floats makes for a safe and reliable working area. Because the ship has basic rigging, a large capacity as well as redundancy, the installation platform is stable and extremely reliable. Over the last few years, the HLV Svanen has not been out of action for a single day of repairs. ‘Nearly one hundred foundations have been laid, without any vessel downtime. That’s very good news for us and for our customers, because offshore time is expensive,’ says Van Bergen.

Short production timesThe Ballast Nedam Offshore work method has another advantage. Nearly all assembly work on the foundations can take place in advance: on land and in a controlled, stable environment. This greatly contributes to the overall quality of the product and shortens production times, since only two assembly activities remain to be carried out at sea. And what is more, these activities are much less weather-dependent.

a dynamic marketVan Bergen and Van de Brug are highly enthusiastic about HLV Svanen, Ballast Nedam Offshore and the offshore wind energy market. Van de Brug: ‘We entered this market at a very early stage. The first wind farm had been constructed in Sweden in the early 1990s, and as early as 1994 Ballast Nedam laid the foundations for the Lely Wind Farm, which was followed by the Offshore Windfarm Dronten. For the first time, we used monopiles as a basis for the turbines for both farms, and this has since become the standard in offshore wind. Surely no mean feat, and a fact we are very proud of!’ Van Bergen continues: ‘Now, more than 10 years later, the market has matured. It has become an interesting and exciting market with a great deal of activity, where a lot is happening at the moment. The political climate, financial developments and technological possibilities all play a part in whether or not projects are carried out. We know that in the northern-European market around 4-5 projects will be realised each year over the coming period. But the question is: which ones will they be? This depends on many factors. For instance, currency exchange rate fluctuations in non-euro countries such as the UK may well threaten the feasibility of proposed projects, as this may lead to certain market vulnerabilities. On the other hand, Germany is currently catching up, which opens up new opportunities.’

a solid foundation for wind energy

DireCTOr marCeL van berGen anD COmmerCiaL manaGer eDWin van De bruG aT baLLaST neDam OFFSHOre

‘Ballast Nedam offers flexibility for

innovations’


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anything is possibleBallast Nedam Offshore focuses on the European market. And this is no problem whatsoever, thanks to the company’s extensive experience and thanks to its specialist sister companies. Ballast Nedam Offshore offers clients a complete package, culminating in the turn-key provision of a foundation. The company can also take care of project development, including financing and permits, design, construction as well as ongoing maintenance. With its 36 turbines, the ‘Egmond aan Zee’ wind farm is one example.

Van Bergen: ‘We can jump on board at any point. Sometimes our clients just want us to provide consulting services during the development stages. Given our extensive experience in the market, we can often provide the exact data they need in order to finalise a project’s financing and get it off the ground. Clients may also call us in for our equipment. In short, we do it all. And since we operate across the entire chain, our clients always do business with people who can see the complete picture, even though we are only brought in for part of the entire project. A huge advantage.’

a single contact point for wind energyIn order to provide this all-in package, Ballast Nedam Offshore works with other Ballast Nedam companies such as Engineering, Funderingstechnieken (Foundation Technologies), Beheer (Operation and Maintenance) and Concessies (Concessions). It is extremely convenient for clients to have a single point of contact for the construction of offshore wind farms: Ballast Nedam Offshore as a one-stop shop. Van de Brug: ‘We ensure full support, coordinate the offer and can refer people quickly.’

Constructability‘Ballast Nedam Offshore combines all the activities required for the construction of offshore foundations, and performs the necessary calculations. Thanks to the close collaboration between our company’s designers and structural engineers, we can always guarantee clients that we are genuinely able to build what we design. That’s what we call constructability’, says Van Bergen. When designing, Ballast Nedam Offshore also bears in mind a park’s expected service life of 20-30 years, and its maintenance needs. Sometimes this means higher initial design or construction costs, but nevertheless results in a smaller overall price tag in the long run.

an affordable alternative to coal, gas and oilIn the near future, Ballast Nedam Offshore hopes to use its innovations to reduce the costs of offshore wind energy even further, so that it becomes an increasingly affordable alternative to coal, gas and oil. Thanks to the current approach to logistics in the construction process, meaning that as much work as possible is done on land, the number of offshore days (and therefore the costs involved) has been reduced considerably. In fact, Ballast Nedam Offshore’s designers are now looking for an even smarter solution, involving the foundation and mast combined as one element and made as one single piece to be installed in a single procedure. It’s sure to be another exciting chapter in our continuing story of development.

‘Ballast Nedam

combines strengths’

Kriegers Flak is a shallow area in the southern Baltic Sea, located in the economic zones of Denmark, Germany and Sweden. This chapter deals with the project in the Swedish part, owned by Vattenfall. The company is the largest Nordic wind power generator, and one of the biggest players in Europe. Although much of its production takes place onshore, Vattenfall also has an ambitious offshore programme.

The Swedish Kriegers Flak project plans to include 128 turbines, each with a capacity of 5 MW, in water that is 17-42 metres deep. Annual production is expected to amount to 2.6 TWh. The type of foundation to be developed has not yet been decided upon. Possibilities include different kinds of gravity based structures, monopiles, tripods and jackets in steel or concrete, or combinations of these.

Foundation evaluation As part of the project development effort, Vattenfall has carried out an extensive evaluation of various types of foundations. Consultants and manufacturers participated in a design and evaluation project specifically tailored to an area like Kriegers Flak.

The work was based on an actual site assessment for the region (geology, wind, waves, currents, ice).

The main purpose of the study was to evaluate the different kinds of offshore foundations suitable for 3-5 MW turbines and for water depths of 20-40 metres. The study was also meant to develop possible improvements (in terms of cost, manufacturing, installation and maintenance) of existing foundation concepts as well as possible new ones.

Foundation concepts The following concepts were studied: a gravity based concrete structure, a conventional steel monopile, a drilled concrete monopile, a steel jacket and a concrete tripod.

The gravity based concrete structure has been used in many offshore projects, such as Vattenfall’s wind farm Lillgrund in Öresund. The technique has been tried and tested and found to be competitive in deep waters such as Kriegers Flak. The project included the development of a floating structure that could be towed to the site, where it was submerged. The steel monopile studied is another concept that has already been used in many projects (for instance for Vattenfall’s wind farm at Horns Rev). This concept, too, can be considered tried and tested.

The drilled concrete monopile presented a new concept, developed by Ballast Nedam, and was found to be very compatible indeed. As a result of high investment costs, the cost per megawatt highly depends on the total number of foundations in the wind farm, but in a large farm such as Kriegers Flak the drilled concrete monopile remains a very interesting and promising concept. Since this application is relatively new, it may need some more development and evaluations before it can be regarded as proven.

In the foundation study, major improvements were made to the steel jacket, for instance by reducing the nodes and thus the amount of welding needed. For this type of steel foundation, a concrete transmission piece was developed: one example of measures that can reduce the estimated costs.The concrete tripod was another new concept. Because this structure is very large (adapted for water depths of 35-40 metres), special attention was paid to manufacturing and transport.

next movesAt present, various licences are being obtained for the Swedish section of Kriegers Flak, and information about the site assessment is being gathered. This part of the process is expected to be concluded during 2009, after which the detailed design for the procurement is scheduled. Allowing a year for procurement and several years for delivering the first foundations, turbines and grid system, installation works could start in 2012 or 2013, although Vattenfall’s profitability requirements may cause some delays here.

Kriegers Flak Foundation Study

Göran Loman

Project Manager at

Vattenfall

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Heavy Lift vessel Svanen: ready to handle the next generation of monopiles

innOvaTiOn

As a part of its offshore working method – producing prefabricated elements on land and installing them at sea – Ballast Nedam requires specific heavy lift equipment. One of Ballast Nedam Offshore’s great strengths is the special equipment it can deploy in support of its projects. And the jewel in their crown is the Heavy Lift Vessel Svanen.

When the Zeeland Bridge was constructed, existing floating sheerlegs were used, but for the King Fahd Causeway in Saudi Arabia the Ibis lifting ship had to be specially developed. This was done by Ballast Nedam. The vessel lifts from its centre of gravity, which significantly reduces the movement of the hoisting load. On the basis of this principle, the self-propelled heavy lift vessel Svanen was designed and built for the Storebaelt Bridge in Denmark. To meet the heavier demands for the Confederation Bridge, HLV Svanen was then enlarged and its lifting capacity further increased to an impressive 8,700 tonnes.

at home in new wind farmsAlthough originally designed for assembling prefabricated bridges, including the installation of concrete gravity-based foundations, this self-propelled catamaran is equally at home in new wind farms, positioning the huge submerged monopiles on which the turbine towers stand. Its lifting capacity is more than sufficient for today’s monopiles, which weigh up to 600 tonnes, and its massive dimensions guarantee a stable platform for offshore ramming work. In fact, the Svanen is ready to handle the next generation of monopiles, which will support 5-7 MW turbines weighing 600-800 tonnes and stand in up to 40 metres of water.

monopile installationBallast Nedam invented, engineered and installed the very first monopile foundations for offshore wind turbines. These monopiles were installed at the Lely near-shore wind farm in 1994 and the Dronten near-shore wind farm in 1996. Both wind farms are situated in the IJsselmeer lake in the Netherlands. Although their dimensions are relatively small by today’s standards (with diameters of up to 3.70 metres and a maximum weight of 89 tonnes) their design and installation principles differed little from the approach used today.

The Svanen’s almost unlimited lifting capacity means that it can handle the installation of monopiles for generations of wind turbines to come. Ballast Nedam has developed an ideal installation method to suit the actual situation of a particular offshore wind farm, its foundation design and related base harbours.

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Ballast Nedam Offshore On the MoveWork method in briefThe floating monopile is upended by the Svanen using a proven work method and is positioned on the seabed within Svanen’s guiding frame. The monopile settles several metres into the seabed, after which the drilling machine is installed inside the monopile. Drilling starts and the monopile is continuously lowered to the required depth. At this point the drill is removed and the drill fluid hardens. The ice cone is placed and grouted on the top of the monopile.

Drilling equipmentThe drilling machine, including the cutter head is designed to drill through the various soil layers. The diameter of the cutter head is extendable. This enables the machine to drill inside and under the monopile. It excavates in two directions and is able to crush boulders in front of the cutter head.

CostA cost estimate for a continuous fabrication and installation process for 128 foundations resulted in the following costs per MW: • 3.6MW≈ €500,000 Euro • 5.0MW≈ €400,000 Euro

ConclusionsThe concrete monopile for offshore wind turbine foundation is technically feasible. •The vertical drill method using the Svanen is technically feasible. •From an economic perspective, the concept is highly competitive. •

One-LiFT COnCePTBallast Nedam has developed a sound and solid installation method based on the deployment of the reliable HLV Svanen.

The need for suitable and efficient equipment for installing increasingly large and powerful turbines demands the development of new concepts that will enable the offshore wind energy sector to contribute to European renewable energy targets.

The HLV Svanen’s large turbine installation method enables the pre-assembly and initial commissioning of the complete turbine in sheltered conditions prior to its actual installation. Once the turbine is ready for installation, it is collected by the HLV Svanen, which then transports the turbine to the offshore installation site. At the site, the Svanen facilitates a safe and rapid operation to complete the installation cycle of the large wind turbine.

revolutionary steps in risk mitigationPerhaps the greatest advantage of the one-lift concept is not the effect on actual installation costs, but rather the fundamental fact that the one-lift concept is actually possible and feasible; that the entire commissioning and testing process can be completed onshore and that we have reduced the number of weather, wave and wind-sensitive operations to be held offshore. This presents a truly revolutionary step in risk mitigation, with a corresponding reduction in overall costs.

innovationTHe PreFabriCaTeD DriLLeD COnCreTe mOnOPiLeFor Vattenfalls research project entitled ‘Foundation Concepts Kriegers Flak Wind Farm’, Ballast Nedam Offshore and MT-Piling (a 50% Ballast Nedam subsidiary) have developed a new foundation concept: the Drilled Concrete Monopile.

The drilled concrete monopile concept is highly innovative. It consists of the installation of concrete monopiles with the help of a drilling method based on the horizontal tunnel-drilling methods Ballast Nedam uses onshore.

background The drilled concrete monopile concept was developed for a number of reasons. First, concrete monopiles are inexpensive compared to steel monopiles: concrete is less vulnerable to price fluctuations. Second, the concrete market has unlimited manufacturing capacity and a wide range of suppliers. Third, underwater noise can be prevented, reducing the environmental impact of installation. And finally, the method can be used for various soil types, even where boulders are present on the seabed.

DesignAt Kriegers Flak concrete monopiles are designed for 3.6 and 5 MW WTGs in water with a depth of 30 metres. The top of the monopile is +3.5m MSL, including a concrete ice cone.

Dimensions 3.6 MW 5.0 MW

Outer diameter (mm) 6,500 6,900

Wall thickness (mm) 500 700

Pile length (m) 61 64

Weight (tonnes) 1,450 2,200

FabricationThe monopiles are made of pre-cast reinforced concrete ring elements and are fitted with a steel cutting shoe to ‘cut’ through the soil, creating an overcut. This overcut is filled with self-hardening drill fluid. The monopiles are transported by floating them to the offshore site.

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During the design stages of a new project, the preparations for the actual installation at sea will have already begun. It is during this stage that Ballast Nedam Offshore project manager Jurjan Blokland takes the lead. Blokland: ‘Working offshore costs a fortune. Every day that you can save through efficient preparation is a fortune saved.’ In between projects, which usually take place in the summer, there is time for R&D initiatives. Project manager Blokland talks about the importance of thorough logistic preparation and the enterprising spirit at Ballast Nedam.

‘When work has to be done at sea, it is vital in operational terms to make sure that you can always do what you need to do. You have to be ready. The most important element here is the logistic process: the trick is to prevent delays and to eliminate any problem areas early on. You can’t just wait for events to unfold and see what happens, because you will find that you have let time slip through your fingers. Sometimes observers say that “the work went well, because the weather conditions were favourable.” We say: “Things went quickly, because our production levels were high whenever the circumstances permitted.”’

Working with a passion for the seaBlokland: ‘Working at sea depends on having all the right people in all the right places: those who work on land, the subcontractors, and staff on the Svanen. At Ballast Nedam Offshore we work with people we know well. Sometimes they hail from one and the same team, such as Ballast Nedam Funderingstechnieken (Foundation Technologies), where they demonstrate the same passion that they show in their work on the wind farm. When the pile-driving boys come aboard, they add a lot of energy, which we appreciate very much. It makes a world of difference.’

innovation from innate enthusiasmR&D does not take place in a separate department at Ballast Nedam Offshore. Blokland: ‘Ideas often come to us spontaneously, sometimes completely removed from our immediate working environment. Ideas emerge from what may be termed innate curiosity and enthusiasm. Sometimes I start the sawing and hammering process at home. But a good scale model showing the technical basis for the idea is not enough – the new concept also needs a solid financial basis. Still, a scale model is extremely important, because plans in the offshore sector really need to be presentable. Once something becomes tangible, ideas come alive. Everybody looks at the model and makes comments, and that’s when an idea becomes a joint project.’

‘We strive for the best solution’Blokland: ‘We consider many issues at Ballast Nedam Offshore. If we see any reason to do so, we determine whether we can develop existing ideas any further. This holds for large-scale innovation projects for the future as well as for short-term solutions. The key idea here is that we can always define two solutions: the easy solution and the best solution. Needless to say, we go for the best solution. And this works.’

‘Solutions should be kept simple’‘We’re not sending rockets to the moon’, Blokland continues. ‘Our work is relatively simple. You need to remain flexible, and not make things needlessly complicated. Solutions should be kept simple and elegant, because these are often the best.

‘ideas simply present themselves, usually on a lazy Sunday afternoon’

For example, we have built a hydraulic mini-robot that can automatically screw on bolts underwater, which means that we don’t need a diving team when there is no time to bring one in. Still, most innovations aren’t developed during the installation process – at that time we’re too busy managing the work and the people doing it. It is mostly the effort you make during preparations that is decisive in the success of a project, not the effort during the work itself or afterwards.’

non-standard workBlokland: ‘We are a group of people who think outside the box and put our backs into our work. We do everything, and this is what makes Ballast Nedam truly unique. We’re not afraid to leave the beaten track and break new ground, and we are used to being confronted with critical and sometimes even unexpected questions. As a company and as a team, you need the guts to take responsible risks. For us, it’s practically standard that our work is never standard.’

‘Working offshore costs a fortune. Every day that you can save

is a fortune saved.’

‘Preparation is the key to a project’s success.’

‘We do everything.

That’s what makes

Ballast Nedam unique.’

JurJan bLOKLanD, PrOJeCT manaGer aTbaLLaST neDam OFFSHOre


Ballast Nedam has achieved many wide-ranging successes with the operation of roads and buildings through long-term concession type contracts, and with a network of natural gas service stations. Given that entrepreneurship and risk appetite are anchored within the culture of Ballast Nedam, three years ago the company decided to develop this concept into an independent business unit: Ballast Nedam Concessions. ‘Because we have all of the ingredients for offshore wind, it was a natural step for us to start getting involved with the development and financing of wind farms’, says Dirk Alma. Alma is an investment manager within this young Ballast Nedam business unit, responsible for private concessions including offshore wind energy.

‘Ballast Nedam Concessions’ strength is that we combine all of the activities in which Ballast Nedam excels, from the start of the chain to the end. Starting in the developmental planning stage, we analyse and coordinate issues such as safety, feasibility, maintenance, operation and life-cycle costs. We take these aspects and

create concrete, feasible business cases, after which we take care of the project financing. Close collaboration with our sister companies creates complete and integrated solutions for offshore wind farms. Ballast Nedam Concessions does this independently for itself as well as in collaboration with or by order of its partners.’

a constant search for synergyAlma: ‘Our investment managers and project managers at Ballast Nedam Concessions work with our legal and financial experts to ensure that the business case is solid. To this end, we monitor the entire chain of activities closely during the entire project, including design, construction, management and financing. Using financial models spanning periods of 25 years or more, we produce a clear overview of the consequences of our actions and decisions. This understanding, in combination with the experience of our sister companies and partners, is the key to the way we create synergy – between the foundations and the turbines, design and construction, design and operation, as well as synergy between risks and ways of financing. This is what enables Ballast Nedam to develop better-quality business cases, generating added value for all parties involved in the project.

High commitmentBallast Nedam Concessions is utterly committed to its projects. Alma: ‘We want to invest in wind farms ourselves, and therefore benefit directly from good-quality, long-term results. We could decide to sell our share in a wind farm after a few years, but that’s not our grounding philosophy. In principle, we remain bound to a wind farm for the duration of the entire contract period, just as with concessions for other types of projects.’

more space for wind farmsAlma: ‘Offshore wind energy is a burgeoning science, still full of questions that we need to answer. For example: what are the effects of pile-driving under water? This issue is still very unclear, and together with advisers we examine matters closely.

With our sister companies, we also examine the technical possibilities for alternative working methods in order to solve problems. Another thing that we look at is the layout of the North Sea – if you take a map of the North Sea and draw in the oil platforms, sand extraction areas and shipping routes, you’ll see that there is little room left for wind farms. Given the government’s major objectives concerning the realisation of wind energy, we are searching for opportunities to free up more space. There is a myriad of opinions, and together with other parties Ballast Nedam is promoting the importance of wind energy.’

Subsidies for offshore wind energy location Permit procedures for wind farms are often long and complex. Alma: ‘Various authorities are puzzling over new elements for which they need to find solutions. They have to deal with political decision making and with new issues involving public participation and legislation.’ In addition, there is sometimes a lack of clarity regarding subsidies. Alma: ‘For the time being, wind energy cannot do without government subsidies which are put out to open tender in various ways.’ Whatever it may turn out to be, with all its years of experience in tendered projects, Ballast Nedam excels in organising and winning these types of contracts. Alma: ‘Although tendering is specialisation in its own right, it is one which Ballast Nedam understands well. And we plan to draw from our experience to create new successes.’

‘Ballast Nedam Concessions creates

synergy’

‘We draw from our experience to create

new successes’

Dirk Alma,

Investment Manager at

Ballast Nedam Concessions

Collaboration: complete and integrated solutions for wind farms

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THe GunFLeeT SanDS WinD FarmThe Gunfleet Sands wind farm is located off the east coast of England close to Clacton-on-Sea. Ballast Nedam installed 32 wind turbine foundations in the farm, in water ranging from 0.5-10 metres in depth. Thirty-two transition pieces were also transported and installed. The HLV Svanen was used to transport the monopiles and transition pieces. Ballast Nedam and MTH cooperated in installing the foundations and transition pieces with the help of the Svanen and its marine crew.

Gunfleet Sands annually generates green energy for around 120,000 households. The construction of Gunfleet Sands contributes greatly to the UK’s objective for 2010: emitting 20% less CO2 than in 1990.

Location: Clacton-on-Sea (UK) No. of turbines: 48, each with a 3.6 MW capacityCapacity: 172 MW Foundations installed: 2009


‘Quality through cooperation in the chain’

Ballast Nedam Offshore supplies a truly unique product. Wind turbines at sea must be able to withstand strong winds from any direction, waves, dynamic forces, currents and sometimes even ice. All of this is reason enough to set high standards for the production of individual components, in order to guarantee the quality of the whole. Director Marcel van Bergen explains Ballast Nedam Offshore’s approach.

Ballast Nedam Offshore evaluates its suppliers on the basis of quality and safety. ‘Our experiences with the supplier play a large part in the assessments, which is why we also call in the purchasing experience of Ballast Nedam Infra Projects, given that they are used to purchasing for large international projects,’ says Van Bergen.

The best solutionSometimes a supplier is also a sister company – this is one way in which Ballast Nedam Offshore builds on its own foundations. Van Bergen: ‘But we can’t supply everything ourselves. The production of steel monopiles, for example, is a field all of its own.

Although we regularly collaborate closely with the same partners, we always remain alert and look out for new parties in the external market. We want to keep abreast of the newest developments and we always strive to find the best solution for our customers.’

Helpful role in start-up companies‘In order to promote variety in solutions, we also participate in various R&D programmes and input our knowledge at the base. We are also regularly involved in start-up companies that wish to enter the market. Thanks to our experience with the process of wind farm realisation from start to finish, we can play a helpful role for companies that develop new products for offshore wind turbines’, says Van Bergen. ‘In this manner, Ballast Nedam Offshore also looks at quality aspects from the outset and increases clients’ options.’

monitoring on the shop floorVan Bergen: ‘In order to guarantee quality, we ensure that the schedule of requirements is clearly set out on paper. Although some clients have lots of experience with such things, others do not and in that case we can take their wishes and convert them into a clear schedule. We also play a monitoring and participatory role with regard to our suppliers. In doing so, we do not refer only to procedures that have been put down in writing – the inherent risks are too great. We regularly visit our suppliers to monitor quality directly on the shop floor.’

‘We always strive to find

the best solution’

Marcel van Bergen,

Director at Ballast Nedam

Offshore

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Ballast Nedam Engineering is trying to take advantage of the imminent scaling-up of offshore wind energy, which will require increased turbine energy outputs. This calls for heavier turbines with stronger foundations. Maarten van der Veen and Patrick van Os both work on the design of wind turbine foundations; Van der Veen as engineering manager at Ballast Nedam Offshore, and Van Os as engineering manager at Ballast Nedam Engineering. Van der Veen: ‘The design of the drilled concrete monopile will enable us to enhance our competitive position.’

The foundation design for modern wind turbines is usually based on the monopile construction; it has proven to be a cost-effective design for most of the wind farms that have so far been erected. The structure consists of a hollow steel tubular pile that is driven into the sea bed, on top of which a ‘transition piece’ is placed. This is also a tubular pile that includes various facilities, such as an entrance in the form of a boat landing, equipment for attaching the electric cables, and the connection to the wind turbine tower.

Various types of foundation constructions are available, depending on the location, water depth and the type of turbine. Van Os: ‘In the preliminary stages we produce a rough design and perform an approximate check of the functionality and dimensions, keeping in mind the sea bed conditions, the type of turbine and the loads involved. Thus, we can obtain a rough idea of what the design will ultimately look like. Sometimes it turns out that the standard design is not suitable and that we need to come up with a new construction.’

Concrete constructionBallast Nedam is encountering increasing competition as far as the existing steel monopile construction is concerned. For Ballast Nedam the choice for a drilled concrete monopile is a logical one. Van der Veen: ‘The market motivation is the price of steel – concrete foundations should be cheaper. Environmental concerns also play a role here. Pile-driving at sea is viewed as problematic for underwater wildlife, but a drilled pile eliminates vibrations. Concrete piles create far less noise in comparison to driven steel piles.’ Van Os adds: ‘We are experts in the vertical drilling of piles into the seabed. Furthermore, thanks to the Svanen we are currently the only contractor able to lift the concrete monopiles.’

Creating support for new designBallast Nedam has carried out a concept study of the concrete monopile as proposed for the wind farm to be built by Swedish energy provider Vattenfall off the coast of Sweden and Denmark. Van der Veen: ‘Vattenfall has announced that our draft design of the drilled concrete monopile is the most realistic of all submitted designs, and also the one that best satisfies their sustainability requirements in terms of price.’ Van Os: ‘Vattenfall is interested, but has not yet given us an actual commission to start building.’ Van der Veen continues: ‘We also need to generate more support for this new concept. We need people to believe that we are truly equal to the task, and that the risks are manageable. We are currently working on getting our design certified, and an independent certification agency is performing the evaluation. In due course we plan to enter the market with a certified design for a drilled concrete monopile.’


The road to a certified design

Maarten van der Veen,

Engineering Manager at

Ballast Nedam Offshore,

and Patrick van Os,

Engineering Manager at

Ballast Nedam Engineering

‘The drilled monopile

creates far less noise in

comparison to a steel

monopile’

‘We are closely involved

in the execution as well

as the remainder of the

process’

-

baLTiC i OFFSHOre WinD FarmThe Baltic I wind farm will be built in the Baltic Sea, approximately 16 kilometres north of the German Darß€ peninsula. Water depths vary from 16 to 19 metres, and the farm will consist of 21 Siemens 2.3-93 turbines and 1 offshore transformer station. Ballast Nedam is responsible for the design and installation of the foundations as well as for the installation of the transformer station.

The foundations for the wind turbines will consist of a 240-tonne monopile and a 200-tonne transition piece. The foundations of the transformer station comprise a 415-tonne monopile and a 1000-tonne transition piece. The trans-former station itself weighs 850 tonnes.

The design has been completed, and installation will commence in Q2 2010.

Location: Darß (DE) No. of turbines: 21, each with a 2.3 MW capacityCapacity: 48 MWFoundations installed: 2010 (scheduled)

20

‘We are on top of the action’Competing operators usually purchase designs from specialised engineering firms that are not associated with contractors. Van Os: ‘At Ballast Nedam everything is tightly interwoven, giving us a strong position in the market. We take the functional requirements (partly from the customer) together with the engineering requirements and turn them into a design for a wind turbine foundation. We write reports and make drawings and calculations. We approach the design from a technical perspective and, simply put, look at how we can create a foundation with the required strength. The strength of Ballast Nedam Engineering is that we are technically well-equipped. We are experts in the field, and very much on top of the actual installation and the rest of the process.

Van der Veen: ‘I operate as the client’s point of contact. I supervise the project through all of its stages, including the design stage. I examine the project from an engineering perspective and consider issues such as the type of equipment we need, how transportation will take place and which problems we may run into. I then inform Patrick about the matters we need to take into consideration in the design, and we formulate the best choices to make.’

Sums and sketchesCalculations form a large part of the design effort. Van Os explains: ‘The foundation is stressed by wind and waves. If a pile were to become stressed due to fatigue, it could collapse. This system needs to be calculated carefully. We need to make the foundation strong enough for it to be able to cope with the stresses involved. Once this calculation is complete and the calculations for the steel piles have been made, they form the basis for the design of the foundation. The resulting sketches are then sent to the steel manufacturer, where they are incorporated into construction drawings.’ Van der Veen: ‘Variations can occur during manufacture or installation. There are always many different parties involved, such as the turbine supplier and the cable supplier, who each have their own requirements. Considering certain variations means that we have to go back to the designers for new calculations to see whether the design will still work.’

applying for projectsProjects don’t simply fall into one’s lap. Ballast Nedam Offshore writes formal applications for available projects on the market and draws up offers for these tenders. An offer may concern a new design, or an evaluation of an existing design. Contract forms vary considerably from client to client. Van Os: ‘A particularly nice project is the Baltic I wind farm off the German coast on which we are currently working very hard. It will be the first German offshore wind farm commissioned by EnWB, a German energy provider. Although we consulted the client on the design at an early stage, many aspects remained unclear. Subsequently an actual contract was put out for the design and installation of the wind farm. EnWB intends to handle the production themselves.’

Securing a strong position: the complete construction of the first Dutch wind farm ‘Projects involving both design and construction offer the greatest possible scope’, says Van der Veen. ‘This means that we can offer clients a complete package – we take care of design, installation and management. Still, we also welcome clients for installation work only, or to rent the Svanen, for example. Starting in 2001, we completely built the Netherlands’ first wind farm off the coast of Egmond aan Zee, which at that time constituted a very special project. I must admit that initially we were still rather wet behind the ears back then and really had to rack our brains, but in Egmond we were able to build on our experience, which has allowed us to secure a strong position in the offshore wind energy market.’

OFFSHOre WinDParK eGmOnD aan ZeeThe Egmond aan Zee wind farm is the first offshore wind farm built in the Netherlands. Its 36 turbines are located 10-18 kilometres off the coast, at a local water depth of 16-22 metres. Ballast Nedam organised the project management, design, manufacture and placement of the monopile foundations and installation of the turbines and cables. HLV Svanen was used to install the foundations.

The construction of the complete Egmond aan Zee wind farm was carried out in collaboration with Vestas, a Danish wind-turbine manufacturer. Ballast Nedam and Vestas together handed this turn-key wind park over to the client.

The Egmond aan Zee wind farm provides green energy to around 100,000 households, reducing CO2 emissions by 140,000 tonnes per year.

Location: Egmond aan ZeeNo. of turbines: 36, each with a 3 MW capacityCapacity: 108 MW Operation commenced: 2006


‘Every supplier has

their own needs’

‘Our experience

has won us a

strong position’

, o

22 23

Ballast Nedam has its own means to provide civil management and maintenance for offshore wind farms: pioneering work within the market. Together with its partners, Ballast Nedam Beheer (Operations and Maintenance) continuously searches for improvements and innovative solutions. As a separate management organisation, we have the time to devote proper thought to innovation within the fields of management and maintenance. Our objective is to build low-maintenance offshore wind farms’, says Vincent Leenders, project manager at Ballast Nedam Beheer (Operations and Maintenance).

Leenders: ‘Offshore maintenance costs are high. Ballast Nedam continuous awareness of a range of relevant issues in the early project stages prevents problems and the stops costs from spiralling during the operations and maintenance stages. This means that our clients stand to profit significantly. Thus, it is extremely convenient that Ballast Nedam can offer a complete range of services: design, construction, operations and maintenance.’

Partners’ knowledge: an indispensible factor‘We maintain long-term relationships with our partners,’ says Leenders. ‘They are important to us, because they possess valuable knowledge and experience in their specific fields of business. Together we investigate how we can make our work more effective, efficient and safe. We want our partners to feel that they are a part of the wind farm. We can achieve great things by applying the knowledge that they have, knowledge that has to be nurtured, shared and developed, so that together we can continue to create innovative solutions.’ Ballast Nedam Beheer (Operations and Maintenance) works exclusively with independent specialists certified for offshore activities. ‘These are people who regularly take training courses on rescue techniques and the dangers of working offshore. Moreover, everybody has passed a medical examination qualifying them for offshore work and all employees know the rules laid down for a wind farm environment.’

effective coatingLast year, Ballast Nedam Beheer (Operations and Maintenance) studied possible improvements in the maintenance of the coating work on wind turbines. ‘We work with professionals, but there is always room for improvement. The maintenance of the coating must be carried out as effectively as possible. Together with the team leader, we investigated where improvements could be made without neglecting safety aspects. The working method has now been modified; next year we will start reaping the benefits. The coating manufacturer may also become involved. If durability and workability can be increased, it will mean fewer visits to the wind farm, allowing us to work more effectively,’ Leenders explains.

eye for detailsPoints for improvement and innovative ideas are always shared among Ballast Nedam’s departments and sister companies. Operations and Maintenance maintains close contact with Ballast Nedam Engineering, Ballast Nedam Offshore and Ballast Nedam Concessions. Leenders: ‘Within the group, we know where to find each other. Knowledge gained during the operations and maintenance stage is passed on to the designers and ultimately reflected in our product, allowing us to raise its level higher and higher. We have a sharp eye for detail and strive for a maintenance-free wind farm. This makes Ballast Nedam truly unique. At other companies, knowledge is often lost to a certain extent, simply because there are various different parties working on one and the same wind farm.’

Strong network position Ballast Nedam Operations and Maintenance is a management organisation – it employs no welders or painters.

‘As a separate ma-nagement organi-

sation, we have the time to devote proper thought to innovation

within management and maintenance’

‘Companies that leave their management to us can rest assured.

It’s what we call one-stop shopping’

Low-maintenance offshore wind farms

The organisation consists of managers with a technical background. Leenders: ‘We always listen to our customers carefully. The primary role of Ballast Nedam Operations and Maintenance is to put our clients’ minds at ease. We hold a strong position in our network and have positioned ourselves well within the offshore wind energy sector. Our partners are loyal and highly dedicated to our common cause. We complement each other well: they engage in the professional ‘hands-on’ work on the shop floor, while we concentrate on operating as a management organisation. In the end the synergy is reflected in our product.’

Stringent safety requirements‘Our safety policy is strict,’ says Leenders. ‘We only deploy people with the necessary knowledge and experience to carry out maintenance work at a wind farm. For example, all the rope access companies we do business with have an IRATA certification, which stems from a certain level of safety. Everybody needs to be well aware of the risks run on open sea, and those risks are carefully evaluated. Together with our clients, we are doing all that we can to keep improving procedures and operations.’

Companies may rest assuredLeenders: ‘In the future, large-scale maintenance (such as the replacement of a damaged boat landing) will involve interaction between Ballast Nedam Engineering, Offshore and Operations and Maintenance. I will gladly pass on relevant tasks to Ballast Nedam Offshore. Our organisations are complementary and can adapt quickly and expertly. After all, we are the only company in the Netherlands to possess all the required knowledge and experience ourselves. Companies that leave their management to us can rest assured. It’s what we call one-stop shopping.’

vinCenT LeenDerS, PrOJeCT manaGer aT baLLaST neDam beHeer (OPeraTiOnS anD mainTenanCe)


24

1982 - 1986The King Fahd Causeway is a dam bridge, 25 kilometres in length, connecting Saudi-Arabia to Bahrain. In technical terms it is constructed in the same manner as the Zeeland Bridge, but its scope is much larger. Ballast Nedam created the Ibis - a crane ship with a capacity of 1700 tonnes - especially for the transportation and installation of the Causeway’s pre-fab elements and foundations.


History focus

1989 - 1992Ballast Nedam designed the Svanen especially for the construction of the Storebaelt Bridge, which links the Danish islands Fyn and Sjaelland. The bridge’s pre-fab elements were so large and heavy that a floating crane was needed, the Svanen, to lift the 6,200-tonne components – nearly four times the capacity of the Ibis, Svanen’s predecessor.

1962 - 1965In the past, Ballast Nedam built a number of highly notable bridges. The most impressive of these (in terms of scope and complexity) were built offshore, of which the Zeeland Bridge is a fine example. Over five kilometres long, this concrete bridge was the longest bridge in Europe. The entire construction consists of pre-fab concrete elements that were attached to each other from the water up. To carry out the construction work, a floating sheerlegs crane was used with a 600-tonne lifting capacity.

1993 - 1997Just like the Zeeland Bridge, the King Fahd Causeway and the Storebaelt Bridge, the Confederation Bridge belongs to the category of mega-structures. The construction of the Confederation Bridge required the use of elements that were larger and heavier still, and so the Svanen was modified accordingly.

Following its transformation, the heavy lift vessel now has a capacity of over 8,700 tonnes and is exact to within a few millimetres. The Svanen is now over 100 metres high.

The Svanen was designed to transport and install pre-fab elements and foundations, and its capabilities are also put to full use in the construction of new wind farms. The floating crane drives giant-size monopiles into the sea bed, on top of which the wind turbine towers are then attached.

25

26


Gijs van Kuik is President of the European Academy for Wind Energy (EAWE). ‘Europe,’ he says, ‘is progressing nicely in the field of wind energy – Spain, Germany and Denmark in particular are making major investments in this area. The Netherlands is keeping pace with most countries, just behind the front runners. This comes as no surprise, since the Netherlands is but a very small part of Europe. Still, not so very long ago we ranked among the top ten European countries with the highest percentage of wind energy compared to the total electricity demand. I believe that we need to work ourselves back into this top ten.’

Favourable conditionsThe Netherlands has particularly good conditions for raising wind energy to new levels. ‘The future,’ says Van Kuik, ‘lies mainly in the offshore generation of energy with the help of wind turbines. The North Sea is shallow, making it extremely suitable as a location for wind farms.

The Netherlands has a formidable electricity infrastructure, and we have relatively large amounts of wind. In addition, the government has compiled a number of plans for the development of offshore wind energy. Still, it takes an incredibly long time before existing plans are carried out. In this respect, bureaucracy is working against us.’

realistic objectivesIn Germany, it’s a very different story. The German government pursues highly stimulating policies where sustainable energy (such as wind energy) is concerned, which means that supply goes up and prices come down. According to Van Kuik, wind energy funding in the Netherlands leaves a lot to be desired. ‘Nevertheless,’ he says, ‘there are still considerable opportunities open to the government. And it must be admitted that their objectives are sound and realistic: the plan is that by 2020, wind energy will supply one quarter of our energy needs.’Van Kuik: ‘We are not lacking in knowledge or expertise, and we have everything it takes to develop wind energy to the point where it can supply one quarter of our energy needs. The Netherlands currently has a share in nearly all offshore wind farms being built in Europe. The Dutch concrete drilled monopile has shown promising results, and we are making quite a contribution to the installation and maintenance of offshore wind farms.’

Permanent activity on the north Sea Studies have shown that by 2050, the Netherlands should be able to supply 40-50 percent of its energy needs using wind power, which Van Kuik says ‘would be a marvellous achievement. First and foremost, I remain concentrated on 2020 and the objectives formulated by the Dutch government. Permanent activity is needed in the North Sea to realise these objectives. At present, the construction of offshore wind farms regularly comes to a standstill, and this is something we simply cannot afford. We are a prime location for the generation of offshore wind energy, and we need to make full use of our potential if we want to reach our goals.

‘The netherlands has got exactly what it takes’

‘The Netherlands needs

to make full use of its

potential’

rHyL FLaTS OFFSHOre WinD Farm

Rhyl Flats itself is an area of shallows directly along the coast of Rhyl. The actual wind farm is located further away from the coast, to the west of Rhyl Flats. Ballast Nedam and MTH cooperated in installing the foundations and transition pieces with the help of the Svanen and its marine crew.

The tubular pile foundations used for Rhyl Flats weigh 230 tonnes, and the transition pieces 180 tonnes. The tubular piles were floated onto the Svanen, and pontoons were used to transport the transition pieces.

Location: Rhyl (UK) No. of turbines: 25, each with a 3.6 MW capacityCapacity: 90 MW per year Foundations installed: 2008

Gijs van Kuik,

President of the EAWE

Ballast Nedam Offshore Ringwade 713439 LM NieuwegeinPO Box 14513430 BL NieuwegeinThe Netherlands

Telephone: +31(0)30 285 37 27Fax: +31(0)30 285 48 41Internet: www.bn-offshore.comE-mail: [email protected]

Ballast Nedam on the moveThis is a publication of Ballast Nedam Offshore. Copy and editing: EPP public relations. Translation: Metamorfose Vertalingen, Taalcentrum-VU. Photography: Marc Heeman (portraits), Ballast Nedam image database. Printing: Vandenberg drukwerken.

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Ballast Nedam Offshore-On the-move