Earlier this year, when Xinjiang Goldwind Science & Technology, one of the five biggest wind turbine manufacturers in the world, set up subsidiary Goldwind USA in Chicago, it did not simply send corporate minions to do things the way they are done in China.
“When companies have done that in the past, without exception, those plans have gone totally awry because there are cultural and business differences and project requirement differences,” said Scott Rowland, the Goldwind USA Vice President of Engineering and one of the North American team’s first hires.
Instead, Rowland said, Goldwind has hired people who have participated in and know the North American market “and then they give them the tools necessary to support their success,” he explained. “Goldwind’s perspective toward the North American team is ‘Tell us what you need to be successful and we’ll support you,’ rather than ‘Here’s our way of doing business and our policy manual, now go forth and use them.’”
The result is both growing business momentum for Goldwind USA and more than half of the subsidiary company’s incipient installed capacity being sourced domestically. “There’s been a lot of brand awareness built over the last six months,” Rowland said.
The biggest differentiator of Goldwind technology is the permanent magnet direct-drive (PMDD) generator. It is an advance on the basic wind turbine gearbox that uses electronics rather than gears to convert the mechanical energy of the wind into the electrical energy it sends to the grid. A direct-drive generator eliminates heavy gears and so reduces a turbine’s weight and moving parts. In doing so, it significantly reduces shipping and building costs, maintenance requirements and reliability issues.
“Fundamentally, the design traces back to some academic work around identifying problems with turbine design,” Rowland said. Six years ago, he continued, Goldwind engineers listed the places where traditional turbines had liabilities and unfavorable performance attributes “and looked to design a turbine that didn’t have those.” In addition to the PMDD, Goldwind has also developed innovative power supply conversion and pitch drive technologies, Rowland stressed.
Its 1.5-megawatt turbine is presently Goldwind’s flagship machine, with 1,900-plus erected worldwide representing over three gigawatts of capacity. “What I tell people about Goldwind,” Rowland said, “is that it’s the largest, most established turbine manufacturer that you’ve never heard of.”
Goldwind’s newer, 2.5-megawatt turbine is part of commercial operations in China but is not yet available in international markets. “The 2.5 [megawatt model] will probably have full specifications and customer information packages available in the first quarter next year, but, realistically, first deliveries to the international market of that machine will be late third quarter or early fourth quarter.”
PMDD technology allows Goldwind to scale up its turbine’s power capacity without adding proportional weight. While it has a taller tower and a greater rotor diameter and swept area, “We were very careful to design the 2.5-megawatt machine such that it could be handled and erected by the same equipment that is in common use in the international industry for the current crop of 1.5 megawatt machines.”
The result is a new, more powerful Goldwind turbine that -- like direct drive machines built by ENERCON and Siemens -- can be erected with a 400-ton crane. The 2.5-megawatt class turbines from manufacturers still wed to gearbox technology require 600-ton cranes, Rowland said, and that entails significantly higher transportation and installation costs.
"A direct drive system eliminates all the gears," Sandy Butterfield, former Chief Engineer of the National Wind Technology Center (NWTC) at the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) explained recently. "Now you're reduced to only two bearings or maybe one bearing that supports a large diameter rotor,” Butterfield, who is now head of startup Boulder Wind Power which aims to build its own direct drive machine, added. “Just from a parts-number-count standpoint, you have a much more reliable machine."
“The elegance of this machine is its simplicity, not its complexity,” Rowland said. Though not true of competitors’ turbines, “you can literally take that same machine,” Rowland said, that is manufactured for Inner Mongolia, “and move it to Minnesota and put it in a field out there, change some software settings, and have it operating.”
A Goldwind 1.5-megawatt turbine with PMDD technology that was erected for research and development purposes in the Bohai Sea in 2007 is still “doing the job it’s designed to do, producing power from wind.” Rowland said the gear-free drive train is key to its durability and reliability. “It’s really a testament to the fundamental premises of the design choices made,” he said. Goldwind is incorporating what it has learned from the Bohai Sea machine into the design of a 5-to-6-megawatt turbine it intends to eventually supply to offshore wind developers as that market ramps up.
“If you look at where a lot of the more recognized turbine manufacturer names are heading in terms of new announcements of prototypes, new acquisitions of companies in order to expand their technology base, you notice a very strong convergence over the last few years,” Rowland pointed out. “Collectively, these design choices represent the machine that Goldwind designed about six years ago,” he said. "We share their opinion that this is the right way to go. It’s kind of nice to hear your competitors say you’re on the right track.”