Suzlon spends $100M to fix cracked-blade problem

Pune, India's Suzlon Energy (BOM:532667) said today it completed a nearly two-year program to upgrade its 2.1-megawatt turbines after two U.S. customers discovered cracks in late 2007.

The $100 million effort resulted in Suzlon redesigning the blades and replacing those still in the field, Duncan Koerbel, chief reliability officer for Suzlon in North America, told the Cleantech Group today. But the problems also resulted in a new set of tests that increase the loads on blades, he said.

"We came out of this with a much more rigorous testing standard that exceeds industry requirements," Koerbel said. "We raised the bar."

In 2008, Suzlon held more than 50 percent of the Indian market for wind and 12.3 percent of the global market thanks to its acquisition of Germany’s REpower Systems (see Suzlon Energy looks to lower debt, after REpower purchase). Suzlon says it was the third-largest wind turbine supplier in 2008.

However, news of the cracked blades took a toll on the company, with Suzlon's shares falling 83.9 percent in 2008 (see Wind giant Suzlon sells off 2 percent stake). The company announced in March 2008 that it planned to spend $25 million for a retrofit to fix the cracked blades (see Suzlon to spend $25M to fix wind turbines). The cost increased to $100 million, which was provided in fiscal 2008-09. 

Suzlon tapped Navigant Consulting for a root cause analysis, which determined that the S88-V2 blade design had a weakness in the transition area, a high stress point that is about 6 meters (20 feet) from the root of the 43-meter blade. The weakness caused cracking in 179 of the 1,251 blades, a failure rate of about 14 percent. 

"We introduced a new product and moved it into the field, and began to see some cracks develop," Koerbel said. "Not everything made in the manufacturing world is identical, and some products might be stronger and other ones might be weaker."

That design passed the industry standards from German wind energy certification organization Germanischer Lloyd (GL), which is why Suzlon has now developed more stringent tests for its products, Koerbel said, declining to say whether he thought the rest of the industry would follow.

"We don’t make policy. It's up to them if they adopt that across the industry or not, but I can speak for Suzlon, and we will adopt that internally," he said.

Suzlon addressed the problem by adding three plies of fiberglass to the exterior of the blade, including over the transition area, and one ply of fiberglass to the interior of the blade. The redesign reduces the stress and strain on the transition area, Suzlon said.

Suzlon retrofitted the 1,251 blades (417 sets) in the field and worked with GL to test and certify the V2 blades according to international standards. Each blade weighs 7 metric tons (15,650 pounds).

The problems initially slowed orders for Suzlon, opening the door for competitor General Electric to revive its Indian wind turbine business after a four-year hiatus (see GE brings back wind business in India with better subsidies).

Koerbel said the ordeal could help Suzlon gain customers' trust because of the quick reaction and thorough investigation.

"When you have issues with any product, customers remember you for how you solve the problem," he said. "From our perspective, our customers are very pleased. We did a very thorough job. You only want to repair these things once."

Suzlon has since introduced a new version of the S88-V2 blades, the S88-V3. Those blades are being used in a 63-MW wind farm that was dedicated today in Arizona. Suzlon said the Dry Lake Wind Power Project is the first commercial-scale wind project in the state (see Iberdrola, Salt River in wind power deal).

Madrid-based Iberdrola Renewables developed and owns the wind project, which uses 30 of Suzlon's turbines. Under an agreement with utility Salt River Project, the wind farm is expected to generate power for 15,000 homes.

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