Vestas has launched its patented Large Diameter Steel Tower (LDST), a solution to increase the tower height for its 3 MW turbines to over 140 meters and increase power production at low-wind sites. On a typical site with a mean wind speed of 6.5 m/s, Vestas claims the LDST will boost annual energy production by up to 8% at a hub height of 137 meters for the V126-3.3 MW, compared to a hub height of 117 meters for the conventional steel tower. As Vestas explains, increasing the tower heights means more force exerted by the wind on the base of the tower, and typically, this requires the use of thicker steel plates. However, the company says the LDST instead increases the diameter of the bottom section, using little extra steel and reducing production costs.
“Vestas’ product development strategy is to continue to optimize our technology in order to lower the cost of energy for our customers,” comments Vestas Chief Technology Officer Anders Vedel.
GE has introduced its new, five-legged space frame tower for multi-megawatt wind turbines. The company says the new product enables towers up to 139 meters to be built in locations that were once difficult to access.
“The space frame tower helps our customers go taller in new locations, further enabling the growth of wind energy,” says Cliff Harris, general manager of GE’s renewable energy business in Europe. “This next innovation in wind turbine technology is a stepping stone toward towers taller than 150 meters in Europe.”
GE is introducing the space frame tower with its new 2.75-120 wind turbine and has demonstrated it in a full-scale turbine at the company’s prototype site in Tehachapi, Calif. The company explains that the lattice tower is assembled at wind farm locations and then wrapped in an architectural fabric to provide familiar solid structural aesthetics.
According to GE, the tower’s five legs offer additional down-tower space, allowing for storage within the turbine and making it easier to perform maintenance, site organization and balance of plant. Furthermore, the company says the tower has a “maintenance-free” bolting system.
The Azimut project, a Spanish initiative aimed at developing a 15 MW wind turbine by 2020, has completed its applied research activities undertaken during the last four years.
The EUR 30.3 million project brought together 11 Spanish companies, coordinated by Gamesa, which include Acciona Windpower, Alstom Wind, Acciona Energia, Iberdrola Renovables, Ingeteam, Imatia, Ingeciber, Digsilent Iberica, Tecnicas Reunidas and Tecnitest.
Gamesa says that upon the project’s completion in December 2013, the different companies have obtained important results in key areas – including new technologies, testing processes and models, and a new Web application – to help with the development of a 15 MW machine.
Alstom has announced an upgrade to its ECO122 wind turbine from 2.7 MW to 3 MW, as well as a new partnership to develop higher towers for less windy sites.
Following measurements taken over a two-month period on an initial ECO122 unit installed in Wieringermeer, Netherlands, ECN1 has certified the machine as a 3 MW turbine.
Alstom has also signed a global partnership with Freyssinet to develop a 119-meter concrete tower specifically designed for its ECO122 wind turbine. This new tower will be made of 11 concrete sections, the lowest measuring 7.2 meters in diameter, for the base of the structure.
This partnership is in addition to a previously signed memorandum of understanding with Max Bogl Wind AG3 to develop a 139-meter tower for the ECO122. Alstom says it will offer its customers both high-tower options, which are suited to harness the stronger winds found at higher altitudes.
Siemens has uprated its D3 onshore platform wind turbines from 3 MW to 3.2 MW. The new SWT-3.2-101, SWT-3.2-108 and SWT-3.2-113 machines will enter serial production by the end of this year.
The turbines will be available with 101- and 108-meter rotors for IEC class IA sites and a 113-meter rotor for IEC class IIA sites. Siemens notes that the 3 MW version will remain available for project sites with lower wind speeds.
The company says improvements in the turbine control system and increased efficiency through the use of stronger magnets are the key factors that allowed Siemens to get more power out of the D3 drivetrain.
Research Leads To
Flexible Blade Tips
LM Wind Power is leading a four-year research project to develop turbine blades with flexible tip lengths – a technology concept the company says has the potential to reduce the cost of energy by 8%-10%.
Supported by the Dutch Ministry of Economic Affairs, the project brings together a consortium of partners including the Dutch University of Twente and the Energy Research Centre of the Netherlands. The project aims to optimize individual wind turbines to their maximum performance by extending the rotor diameter with variable tip lengths.
“The cost of wind power, especially offshore wind power, needs to go down to compete with other energy sources, and we are committed to making that happen,” says Roel W. Schuring, LM Wind Power’s vice president of engineering. “This project with our Dutch partners aims to help wind farm developers and wind turbine manufacturers to design wind farms better and to get the most from each turbine. This will improve annual energy production and reduce cost of energy. The potential is huge.”
LM expects the flexible tips to be manufactured separately and assembly to be done on- or near-site. The new rotor blade will also be a universal solution that can be adapted to various turbines and applied in every wind farm, LM adds.
Leine Linde Systems GmbH has announced its new ADSR product, a slip ring for wind turbines that has an integrated diagnostic system for analyzing condition and predicting remaining service life.
Pitch slip rings, which supply the rotor hub with voltage, signals and data, are subject to wear, and Leine Linde says the ADSR’s diagnostic system continuously monitors the contact systems and other key functions of the slip ring, enabling condition-based maintenance.
The ADSR’s integrated sensors measure vibrations, the level of voltage and current, revolutions, internal and external humidity, and temperature. The company says the information and warning messages sent via the diagnostic system are displayed by an LED on the slip ring and made available using network interfaces. Maintenance personnel can use a browser-based Web monitor to view the current status, as well as reports and analyses.
Romax Technology has been selected by the U.S. Department of Energy (DOE) as the lead mechanical engineer in a consortium project to develop an innovative drivetrain design that could be scaled for large turbines and ultimately reduce the cost of wind energy.
The DOE’s National Renewable Energy Laboratory (NREL) is running the $3 million project, and the consortium also includes CREE, DNV, the DOE’s Oak Ridge National Laboratory, GE Wind and Vattenfall Windpower. Romax says the team’s concept will scale to ratings as high as 10 MW.
According to the company, Romax’s gearbox design will consist of a single, planetary stage that reduces part numbers by eliminating higher speed gear stages and investigates the use of planet journal bearings for minimizing planet stage size.
Romax explains that its involvement in the project started in 2011, when it was selected to be part of an NREL team that competed against six other groups to conduct a study of advanced drivetrain technologies. The team was one of two awarded funding for a follow-on phase to build a prototype and demonstrate the commercialization of the technology.
“After successfully completing phase one, phase two will give us the opportunity to fabricate and test a megawatt-scale prototype drivetrain to prove our design innovations,” says Christopher Halse, Romax U.S. engineering manager. “The drivetrain will be tested in the NREL’s 2.5 MW dynamometer and will utilize the NREL’s newly commissioned Controllable Grid Interface to replicate the loads wind turbines undergo in the field.”
3TIER, a renewable energy assessment and forecasting company, has announced the public release of wind and solar annual averages from its global datasets as part of Google’s Map Gallery launch.
Through its collaboration with Google, 3TIER says it aims to improve access to wind and solar resource information by making it freely available to both researchers and the general public in Google’s platform.
“At 3TIER, our belief is that better information empowers smarter decision-making,” says Pascal Storck, 3TIER’s global director. “Google’s mission to organize the world’s information and make it universally accessible and useful is well aligned with our goal, and we are thrilled to be a part of this launch.” w
Products & Technology
Vestas Unveils Tall Tower...
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