The Eco Wisper mount on a hinged tower that has been lowered to access the 20-kW turbine. The 30 blades are said to rotate almost without noise.

Renewable Energy Solutions Australia (RESA) is the owner of what it calls the world’s most advanced silent wind turbine for mid-sized applications, about 20kW. The turbine features a 30-blade design that is almost silent and up to 30% more efficient than traditional 3-bladed designs. The Eco Whisper Turbine stands 21.1-m high and can produce high energy in low or high winds with a footprint of only 21 m². In comparison, the same output from solar panels would require 250 m².

Following two years of development and testing in Australia, the turbine is ready. It’s first commercial installation is in Tullamarine. The turbine was a finalist in the 2011 Australian Cleantech Awards and was recently awarded a $250,000 commercialisation grant from the Australian government.

The Eco Whisper Turbine can offset medium to large energy requirements. It is suited to commercial, manufacturing, and industrial sites and other applications. It also works on and off grid application with a particular focus on remote communities and diesel replacement.

Other plusses are that it collects wind more efficiently and there are no turn away losses, it delivers more energy from more common wind speeds than three bladed designs, and it performs well in all wind conditions (lower start up speed compared to competitors)

Eco Wisper Turbines

Windpower Engineering & Development

The onshore turbine is similar to the 6 MW offshore unit. LM Wind Power supplies the wind industry with operations from 13 manufacturing facilities worldwide, and more than 140,000 blades produced since 1978.

LM Wind Power’s 73.5-m blades became the first 70+ meter working blades to be installed when Alstom inaugurated the largest offshore wind turbine in the world on March 19 at Carnet in the Loire-Atlantique region of France.

The impressive composite structures have been developed specifically for Alstom’s Haliade 150-6MW wind turbine in a close collaboration between the two companies to boost energy capture while keeping loads down. The innovative blade design has already been through several rounds of testing before being installed on the turbine in France.

“It was great to see LM blades mounted on the newest and biggest turbine in the world as well as see the excitement this technological leap has made in the offshore world,” says LM Wind Power VP Sales & Marketing Ian Telford. “Our technology lets us design and manufacture relatively lighter glass fiber and polyester blades for the length, but above all, the company has proven ability to handle the industrialization of these blades, which is not easy.”

Alstom’s Haliade 150-6MW turbine has been EDF-EN / Dong Energy’s choice developed in response to a call for tenders launched by the French government that aims to install 3 GW of wind turbine power off French shores by 2015. Depending on the results of the tenders, Alstom and LM Wind Power plan to establish a blade manufacturing facility in Cherbourg with capacity to produce up to 100 sets of 73.5 meter blades per year. Production is planned to start in 2016.

LM Wind Power
www.lmwindpower.com

Windpower Engineering & Development

The company has developed products that meet low VOC requirements and have short curing times, which means more efficient production. And we’re currently working on other exciting projects for wind towers.” All this means lower production costs for wind turbine and tower manufacturers. A key element of the company’s strategy is a willingness to customize products for the wind industry and offer onsite technical support.

Hempel’s product portfolio for wind turbines consists of products based on epoxy, polyurethane, zinc silicate and polyaspartic, as well as a range of waterborne anti-corrosive products. Besides adhering to industry standards, the company’s protective coatings are durable, provide ultra-violet (UV) stability, and are abrasion-resistant.

Hempel
hempel.com

Windpower Engineering & Development

As wind-turbine manufacturers seek additional ways to reduce costs and improve performance, greater focus has turned to improving modeling techniques as a way to reliably predict wind-turbine behavior prior to expensive prototyping and testing. In particular, better-designed wind-turbine blades are more effective and they create significant savings for the tower and drive train, major components in the overall system. In this regard, they reduce the initial and operation costs of the entire system, increasing overall competitiveness.

A wind turbine blade as modeled in VABS appears in the Siemens NX8 CAD user interface.

Originating in the aerospace industry for composite helicopter rotor blades, VABS software recently gained the attention of the wind industry for its capabilities in realistic modeling of wind-turbine blades. The program offers users a powerful, general-purpose cross-sectional analysis tool to calculate sectional properties, including structural properties (tension center and neutral axis, centroid, elastic axis and shear center, shear correction factors, extensional/torsional/coupling/bending/shearing stiffness, principal bending axes pitch angle, modulus weighted radius of gyration) and inertia properties (center of mass and gravity, mass per unit span, mass moments of inertia, principal inertia axes pitch angle, mass weighted radius of gyration). Using VABS for efficient, high-fidelity design and analysis, two to three orders of magnitude in computing time can be slashed relative to 3D FEA analyses, and without a loss of accuracy.

Available from AnalySwift, VABS, which now in version 3.6, implements various beam theories based on the concept of simplifying the original nonlinear 3D analysis of slender structures into a 1D nonlinear beam analysis using a powerful mathematical method, the variational asymptotic method. VABS models structures for which one dimension is much larger than the other two (i.e., a beam-like body), even if the structures are made of composite materials and have a complex internal structure. It takes a finite-element mesh of the cross section including all the details of geometry and material as inputs to calculate the sectional properties, including structural properties and inertial properties. These properties are needed for the 1D beam analysis to predict the global behavior of the slender structure. The 3D pointwise displacement, strain, and stress distribution within the structure can also be recovered based on the global behavior of the 1D beam analysis.

Enabled by VABS, analysis can be done as efficiently and simply as conventional beam analysis, without losing accuracy compared to more complex and time-consuming 3D FEA. Users can confidently design and analyze real structures with complex microstructures due to this unique, efficient, high-fidelity feature of VABS. For example, structures as complex as real composite rotor blades with hundreds of layers can be easily handled by a laptop computer.

The screen shot is of the NX 8 interface.

VABS is implemented using finite element techniques with a general element library that includes all the typical 2D elements such as 3, 4, 5, 6-noded triangular elements and 4, 5, 6, 7, 8, 9-noded quadrilateral elements. Users are free to choose the type of elements, and different types of elements can be mixed within one mesh, if necessary. This flexibility lets VABS model beams of any shape.

The program can also deal with arbitrary layups. For instance, users can provide one parameter for the layup orientation and one parameter for the ply orientation to uniquely specify the material system in a global coordinate system. Nine parameters can be used for the ply orientation when a ply is highly curved and the ply angle is not uniform within an element.

There is no requirement that the beam reference line be the locus of cross-sectional area centroids. VABS can calculate the centroid for any arbitrary cross section, and users can choose their own reference line for the convenience of the 1D global beam analysis. Furthermore, it can deal with isotropic, orthotropic, and general anisotropic materials.

According to Dr. Dewey Hodges, an expert in rotorblade modeling and FEM, and Senior Advisor to AnalySwift, “Because VABS is based on an asymptotic approximation of 3D nonlinear anisotropic elasticity, for a comparable set of variables it will always give results that are at least as good as the best engineering approach to beam modeling.”

A design-driven preprocessing program, PreVABS, generates high-resolution finite element modeling data for VABS. It can model sophisticated cross-section configurations for various composite blades. It also significantly reduces intensive modeling efforts for generating 3D FEA models, which is either time consuming or impractical, especially during the preliminary and intermediate design phases.

Commercialized by AnalySwift, VABS was originally developed at Georgia Tech and later significantly enhanced at Utah State University. Developers, users, and academic publications have extensively verified its accuracy, with continuous development spanning over 20 years. Several wind-turbine manufacturers, national labs, U.S. Army, and others are using VABS. Evaluation licenses of VABS and PreVABS are available at no cost through AnalySwift.

The program can be quickly and conveniently integrated into other environments such as computer-aided design software, multidisciplinary optimization environments, or commercial finite-element packages. Additionally, a VABS interface for the widely used Siemens NX Advanced FEM software is now available from MAYA HTT.

AnalySwift LLC
www.AnalySwift.com

Windpower Engineering & Development

The new 2.75-103 wind turbine generator also sports an improved electrical system and has been fitted with 50.2-meter rotor blades of GE’s design. Compared to the 2.5-100 model, the blades used on the new unit are capable of increasing the annual energy output by more than 9% at a wind speed of 7.5 m/s.

A major U.S. turbine OEM says it has a contract with a leading German project developer, Energiekontor AG, for four wind-power generating projects comprised of 41, 2.75 MW-103 wind turbines. Using a proprietary 50.2-m blade GE’s 2.75-103 wind turbine provides a larger blade swept area giving wind developers greater energy capture and improved project economics. The new units will boost GE’s contribution to clean and efficient energy production by generating some 250 million kWh of electricity a year

The 41 wind turbines will be manufactured in Salzbergen in Lower Saxony. The turbines will feature a 98.3-meter-high tower and a rotor diameter of 103 meters to capture more energy.

“GE is meeting the project’s strict noise control regulation requirements by using optimized trailing-edge serrations on its 2.75-103 range wind turbines. The technical design of these high-performance wind generators with their low noise emission levels is one of the main reasons we have chosen GE as our project partner,” said Peter Szabo, Energiekontor’s managing director.

Energiekontor also signed a service agreement with GE including an extended spare parts and servicing contract for maintenance, routine inspections, and remote monitoring, along with manual resets to be undertaken by on-site service technicians and technical measures for troubleshooting and fault rectification.

GE
www.ge.com

Windpower Engineering & Development

The show was hosted by a London-based company. I find there’s just something about the British accent that adds an extra air of pleasantery during the registration and moderation. A representative from Make Consulting started things off by touching on a hot topic: the extension of the PTC. The company says it expects the credit to be renewed, probably for another year, after the November elections. This is an opinion I also heard at the ABB event earlier this week. I have to say it makes sense, as it’s a shame clean energy has become an area of political division when what it really needs is bipartisan support. But I suppose, in this political climate, we should be thankful just to have it renewed in the nick of time.

Make Consulting also noted that many of the turbines online today are becoming outdated. Even 5-years-old models are starting to be considered old-fashioned and could benefit from upgrades or repair—though it’s hard to know how much value doing so holds for availability, and financing isn’t easy.

All about predictive maintenance
Stuart Cameron from Romax Technology discussed a point I’ve heard often lately in the wind industry. He encourages the shift from reactive to predictive maintenance. Out of reactive, preventive, and predictive maintenance, predictive offers the best balance of failure and maintenance costs. Cameron says predictive maintenance offers up to 50% cost reduction over reactive maintenance. This is especially helpful with turbine drivetrains and gearboxes because the industry is seeing an increasing failure rate in these components. Moventas agrees, stressing condition monitoring and understanding what went wrong the to help prevent problems. The representatives also noted that performing maintenance tasks together as much as possible is important to saving time and money.

A bit on blades
The same is true for blade maintenance. Getting up-tower is time consuming and costly, so it makes sense to performance as much maintenance as possible while you’re up there. Wind Energy Solutions (WES) gave a great presentation on blade predicaments and encourages predictive maintenance as well. The company representative recommends starting a database on blades at the end of the warranty and deciding when to do maintenance ahead of time (probably during the non-productive season). He also suggests keeping to a periodic maintenance schedule. For blades, things to check for include rotor and aerodynamic imbalance, which are often due to installing blades at incorrect angles. He says the biggest aging issue with wind blades is leading-edge erosion. The problem can be fixed little by little with protective tapes or coatings.

WES says scheduled maintenance makes common sense because it increases availability, reduces large repairs by focusing on fixing smaller ones first, reduces crane and mobilization cost, and increases aerodynamic efficiency. However, due to lack of data to support cost savings, the WES representative says he has a hard time convincing operators that this is the way to go. The second biggest problem is lightning damage, which can be rectified through lightning-system testing. There are also problems with icing, but without any effective solutions. “If I had the solution, I’d be making some big money,” as he puts it.

There were many other informative sessions including some on improving gearbox reliability, collecting data to improve availability and more. I’d say the conference was definitely worthwhile, and so was my trip to Dallas. But now it’s back to Cleveland for me. After a week away, I’ve learned a lot. But I think I’ve had enough of hotel rooms for awhile.

Windpower Engineering & Development

Wind turbine blade manufacturer GBT USA (Global Blade Technology) announced in mid-September 2011 it would be opening a production plant in the U.S. has seen quite a bit of growth in the last four months. In that short time, GBT USA has secured two major blade production projects on the floor and is gearing up to start production on more. The company says it has increased the size of its U.S. team to include engineers, team leaders, and production staff. It expects to see the first blades rolling out the doors in April 2012. The Evansville, Indiana facility will have the space to produce molds and wind turbine blades in excess of 80-m long in a 45,000 ft² production floor.

Global Blade Technology
www.gbtholding.com

Windpower Engineering & Development

Building upon the recently developed sizing technology applied to Advantex SE2020, the HiPer-tex W2020 is also engineered for epoxy polymer systems used in resin infusion or prepreg processes.

3B’s technological expertise and manufacturing know-how delivers a high modulus glass with outstanding mechanical properties providing significantly greater strength and strain-to-failure than traditional E-glass. The HiPer-tex W2020 offers these properties in a typical unidirectional laminate (average glass volume fraction 60%):

• 54 to 56 GPa E-modulus
• 55 to 60 MPa transverse tensile strength
• 10 times longer lifetime in fatigue resistance versus traditional E-glass

Compared to blades manufactured with traditional E-glass, HiPer-tex W2020 achieves up to 10% weight saving for the same blade design and length. Alternatively, blade length can be extended by up to 6% while maintaining the same weight but offering up to 12% more energy output.

The material offers better wet-out therefore a more consistent laminate quality. A significantly improved resin-matrix adhesion provides higher shear strength and substantially greater interfibre strength when compared with existing high modulus fibre glass.

Onur Tokgoz, 3B wind energy global business leader: “3B is collaborating with the whole value chain in the wind industry sector to bring to market new cost competitive and high performance reinforcements which further push the limits of glass fibre-rotor-blade designs.”

3B-the fibreglass company
www.3b-fibreglass.com

Windpower Engineering & Development

Fibersim assists with support for conceptual designs, defining detailed laminates, simulating ply layup and generating manufacturing data feeds to verifying quality.

Fibersim software version 2012 reduces risk throughout the wind energy, aerospace, and automotive industries by optimizing design and manufacture of innovative, durable, and lightweight composite structures. The software, developed by Vistagy, was acquired by Siemens on December, 2011. Fibersim 2012 reduces uncertainty in the performance of composite parts by defining, communicating, and validating required fiber orientations throughout a product’s development, ensuring it meets specifications. By eliminating design interpretation errors, the new release reduces the risk of producing over-engineered parts that behave unpredictably, or are heavier and more costly than necessary.

The software assist with support for conceptual designs, defining detailed laminates, simulating ply layup and generating manufacturing data feeds to verifying quality. Fibersim works with industry-leading, 3D commercial CAD systems. A few benefits of Fibersim 2012 include:

• ·         Increased confidence in the way manufactured composite parts perform by providing a new Spine-Based Rosette. It allows defining fiber orientations along a path that can be validated throughout a development cycle. Maintaining fiber orientations in manufactured parts—whether an airframe stringer, an automotive C frame, or a 60-m wind turbine blade.
• ·         In 2010, the software introduces advanced material and process simulations for multilayered materials, including non-crimp fabric and ply forming simulations. Fibersim 2012 builds on these capabilities to simulate a greater number of materials and manufacturing processes used with the first-ever Spine-Based Simulation for parts produced using steered-fiber methods. Steering fibers along the path of a wind-turbine-blade mold will cause localized buckling and deformation. Identifying these issues early in the design cycle allows making decisions to ensure expected part strength in a timely and cost-effective manner.
• ·         The recent version allows the exchange of Multi-axial Material and Core data for the communication of two critical design components between analysts and designers. Accurate analysis of part stiffness and strength necessitates the inclusion of multi-axial and core materials commonplace in aerospace, automotive, and wind energy designs.

• The software simplifies composite development with intuitive tools for design and documentation for engineers with different levels of composites experience. The most challenging and time-consuming design task is capturing drop-off specifications for regions of varying thickness. Fibersim 2012 introduces Stagger Editor, a visual drag-and-drop method for capturing those specifications. Large panels, such as wings, have a significant number of different drop-off profiles. The Stagger Editor makes it easy to develop the profiles and reduce design errors.

Siemens PLM Software
www.siemens.com/plm.

Windpower Engineering & Development

“The HSP-7401 primer and AUE-50000 Series topcoat sets a new standard for efficiency and will significantly increase blade protection and durability while also lowering production and life-cycle costs,” says  Dave Chapman, PPG global marketing director, commercial coatings.

The coating series was developed through extensive global testing against a wide range of blade coating standards and specifications. The polyurethane primer and topcoat components were designed together. Using up to 60% less applied film than conventional polyurethane multicoats, they provide outstanding adhesion and flexibility. HSP-7401 primer delivers outstanding adhesion to the composite substrate, the primary attribute required in wind turbine blade finishing. It is quick-drying and may be topcoated in as little as 30 minutes.

AUE-50000 is an extremely erosion-resistant, weather-resilient polyurethane topcoat that offers the smoothness and protection from environmental attack elements required in wind blade applications. The system is also VOC-compliant to 420 g/l. The two components balance performance properties that deliver long-term, low maintenance asset protection in any operating environment including challenging desert and offshore situations. PPG has been producing coatings for wind turbine blades for more than 30 years.

PPG Commercial Coatings
www.ppgcommercialcoatings.com.

Windpower Engineering & Development