Wind Power

Amir Mikhail: Wind Industry Engineering Leader

Issue 3 and Volume 2.

Mikhail’s career has centered around the wind power industry. Turbine designs created under his leadership helped grow Zond, the pioneering wind energy company, into the industry-leading position it now enjoys as part of GE Energy. More recently as senior vice president of engineering at Clipper Windpower, Mikhail plays a key role in building that company to its No. 2 position among U.S.-grown wind manufacturers.

“I began working with Clipper from Day 1,” says Mikhail, who spoke from corporate headquarters in Carpinteria, Calif.

Besides his leadership roles at both Zond and Clipper, Mikhail also holds what many count as a coveted low employee number from the National Renewable Energy Laboratory. His employee number is around 750, virtually a pioneer among the thousands who followed since he worked at the Colorado-based laboratory in the early 1980s.

Mikhail’s career also included time as chief engineer at Zond where he helped that company grow and become first Enron Wind and later GE Energy Wind. After leaving Enron Wind in 2000 Mikhail followed former Zond CEO James Dehlsen to upstart Clipper Windpower. There, he became principal engineer and was one of the company’s first employees. Clipper may be best known for designing and building the 2.5 MW Liberty wind turbine, more than 500 of which are deployed. Having launched that product, Mikhail is now leading engineering design work for a 10 MW machine known as “Project Britannia” planned for Europe’s offshore wind market.

Mikhail earned a B.S. in Aerospace Engineering and Mathematics from the University of Cairo and an M.S. and Ph.D. in Aerospace Engineering from Georgia Institute of Technology. While at Georgia Tech in the early 1970s, the U.S. faced its first energy crisis, the result of an OPEC-imposed oil embargo. The crisis prompted creation both of the Department of Energy and the Solar Energy Research Institute, which became NREL. The crisis also prompted Mikhail to focus his research on techniques to extrapolate wind speeds along the surface of the earth, similar to methods used for the boundary layer on aircraft wings. Models he helped develop were used to evaluate and plan some of the earliest wind farm projects.

One notion that came from his research was the idea that greater geographic diversity of wind resources can help improve grid stability by increasing the size of electricity balancing areas. One problem with today’s grid is its highly balkanized nature, Mikhail says. Enlarging balancing areas to encompass larger amounts of wind generating resources makes sense. “I am talking about hundreds of thousands of megawatts of wind capacity,” he says. At present some 2 percent of U.S. electrical load is supplied by wind. The geographic diversity models Mikhail worked on 35 years ago become crucial as wind penetration levels reach 20 to 30 percent of total generating capacity. Mikhail’s earlier models have been reconfirmed by the Department of Energy’s 20 percent by 2020 study, which indicates wind can supply 20 percent of U.S. demand by 2020. Such levels are emerging in places like Texas and the upper Midwest.

Following his work at Georgia Tech, Mikhail joined the federal renewable energy laboratory. In 1984, however, the Reagan Administration cut federal funds for renewable energy, the laboratory suffered layoffs and Mikhail weighed his options.

“I felt that if I really believed in the viability of renewable resources and in having less dependency on foreign oil that I should work in private industry” where the vision was actually happening, Mikhail says. He left NREL to work as an engineer in California’s wind industry, then joined Zond in 1989 as engineering vice president.

Zond was not immune to the federal funding cuts. But Mikhail says the company survived because its management “had the solid belief that wind is not a tax shelter industry but is here to stay.”

One of his first projects was to improve the efficiency and reliability of the 50kW to 150kW, Danish-manufactured turbines that were the mainstay of the U.S. wind market. At the time, wind blade failure was a problem. Zond became a turbine blade maker and began replacing blades on the over 2,000 turbines the company managed and serviced. It also built one of the largest wind farms at the time, the 78 MW Sky River Project.

But Zond didn’t want merely to import machines and build wind farms. Instead, it saw an opportunity to develop a home-grown U.S. manufacturing base. With a grant from NREL, Zond in 1994 built a prototype 50kW wind turbine, one of the first to use an airfoil for its blade rather than an airplane wing-based design. The turbine also used an integrated gearbox housing, which included a large-scale variable pitch rotor. Such innovations helped drive down the cost of wind-derived electricity from 30 to 40 cents/kWh in the early 1980s to the current 6 to 8 cents/kWh, Mikhail says.

Zond introduced a 750kW machine in 1996, which helped “put us on the map as a high-growth wind turbine company,” he says. That machine’s success attracted a $100 million investment from Enron, whose backing led to a five-fold growth surge between 1997 and 2000. Mikhail left Zond in late 2000 (a year before Enron’s collapse and the renamed Enron Wind’s sale to GE Energy) to follow Jim Dehlsen to his newly formed company Clipper Windpower.

Clipper pursued an NREL program whose goal was to develop a low wind-speed turbine. Its objective was to develop a technology capable of generating electricity more efficiently from lower quality wind resources. Clipper won a $9 million grant and began work developing what would become its Liberty turbine, a 2.5 MW machine with a variable speed system that replaced traditional doubly fed induction generators with a permanent magnet generator. Mikhail says the permanent magnet offers a low-voltage ride through that can prove helpful in avoiding the sort of cascading power failure that hit the northeastern U.S. in 2003.

One ongoing sore spot for the wind energy industry has been the failure rate of wind turbine gearboxes. “The gearbox has been an Achilles heel,” Mikhail says.

One reason is the enormous force it must endure. A wind turbine gearbox must convert high torque and low RPM energy from the blades to a lower torque at a higher speed to spin the generator. Mikhail says the high bending loads that result from the turbine rotor can affect gearbox teeth contact patterns. As a result, a gearbox can see as much metal fatigue over the course of a year as a family car sees in its lifetime.

Clipper built its own gearbox test-bed so now each of its gearboxes is tested, which has improved the company’s quality control efforts. The turbine also featured a multiple generator or “quantum drive” design that includes two instead of three gearbox stages. This allows for a more intense distribution of torque, which helps reduce the generator’s overall size and weight, crucial in driving down costs.

Clipper began testing a prototype 2.5 MW machine in 2005. Following the Liberty turbine’s certification in mid-2005, Clipper went public with a listing on the London Stock Exchange’s AIM. “We raised enough money to start a manufacturing facility in Cedar Rapids, Iowa,” Mikhail says. The first Liberty sales took place in 2007 and the company now has more than 500 of the turbines deployed in the field.

Not without incident, however. While the technology was solid, the company encountered startup problems caused mostly by component supply chain quality issues. This led to what the company told shareholders were “two significant and expensive remediation programs.”

But that didn’t deter Clipper or Mikhail from starting to plan the company’s next-generation technology. The latest design challenge is a 10 MW machine aimed at Europe’s offshore wind market. Original plans called for building a 7.5 MW machine, but that quickly escalated to a 10 MW machine for reasons having more do with economics than corporate hubris, Mikhail says. After all, 70 percent of a land-based turbine’s cost is made up of the turbine. The rest represents balance of plant. Offshore, the ratio flips. Britannia’s goal is to increase turbine size while minimizing costs for undersea cable, foundations and towers.

In 2008, Mikhail and 15 engineers from Clipper and its network of consulting engineering firms began design work for Britannia, which will include a 72-meter blade, longest in the world. The gearbox will include Liberty design elements, including a compact design to reduce weight as well as a variable speed drive. The machine is due for delivery in mid-2012 to help meet a market demand that could reach 35,000 MW in the U.K. alone.

Looking back at his 35-year career, Mikhail says he gains the greatest satisfaction from the team of engineers and consultants he has helped put together, starting at Zond and now at Clipper. Those engineers form the core of U.S.-grown large-scale wind manufacturing.

“We are responsible for the only two U.S. OEM wind manufacturers,” he says. In part, it’s important for wind power to win market share from coal- and nuclear-based generation and also to help reduce U.S. dependency on foreign oil, he says. But, from his vantage point atop the wind industry’s engineering “family tree,” Mikhail says it’s also important to have indigenous U.S. manufacturing. “That’s the most satisfying part.”