October 12, 2009
Suzlon completes blade retrofit program
- All turbines with retrofitted blades delivering consistent performance
- Program sets new benchmarks for blade testing and validation
- No additional retrofit costs in FY2009-10
Pune: Suzlon Energy Limited (SEL), the worlds third leading* and Indias largest wind
turbine manufacturer, announced the completion of its worldwide program to
strengthen and reinforce all Suzlon blades of the V2 type on its ">S88 2.1 MW turbine
fleet.
Instances of blade cracks were first discovered in late 2007 during the operation of
some of Suzlons S88 wind turbines in the United States. Suzlon responded
immediately and launched a detailed root cause analysis and identification process,
followed by extensive testing of the solution and a comprehensive retrofit operation to
safeguard and enhance 1,251 (or 417 sets) of S88-V2 blades around the world a
commitment of approximately USD 100 million, already provided in FY2008-09.
Said Mr. Andy Cukurs, Chief Executive Officer of Suzlon Wind Energy Corporation: We
are happy to report the completion of the program in September, 2009. This project
has been a priority effort for us, and our Technology and Project teams have worked
hard to complete this project within the shortest possible time. After receiving the first
report of cracks in the S88-V2 blades, we immediately undertook a root cause analysis
to identify the problem, devise a solution, and resolve the issue in a timely and costeffective
manner. We believe we are the custodians of our customers investment and,
in keeping with our commitment to our customers, decided to retrofit the entire S88
V2 fleet and replace the few cracked blades at our own cost to eliminate any possibility
of further issues, no matter how small the chance.
In parallel with strengthening the S88-V2 blades, Suzlon also introduced the nextgeneration
S88-V3, which is consistently delivering and exceeding performance
standards at windfarms around the world. One of Suzlons S88 turbines produces
enough energy to power approximately 500 average American homes.**
Speaking after the completion of the retrofit program, David A. Drescher, Vice
President - John Deere Renewables, said: We are pleased that Suzlon has completed
the replacement of the blades in our S-88 fleet and is addressing other product
support requirements.
Speaking on successful completion of the S88 type certification with the modified blade
design, about the testing protocol applied Christian Nath, Vice President -
Germanischer Lloyd, said: Analysis that implies the effect of 3-D loading and design
was used for the verification of the modified blade design. Testing beyond the normal
scope of IEC 61400-23 was applied to prove the designs feasibility."
The Retrofit Process was carried out in a multi-stage process detailed below:
Root Cause Analysis and Identification
Working directly with its customers, Suzlon engaged Navigant Consulting, a
leading international consulting firm, to conduct an extensive Root Cause
Analysis (RCA) examining all primary and secondary contributing causes to the
blade crack issue.
? The RCA team concluded that the S88-V2 blade design, while designed and
tested to industry standard certification guidelines, had a weakness in the
transition area about 6 meters (20 feet) from the root of the blade. The
blades measure 43 meters (142 feet) long and weigh 7 tonnes (15,650
pounds).
? At the completion of the program, only 179 blades of the total fleet of 1,251
blades developed cracks. However, Suzlon upgraded the entire fleet in support
of its customers.
Design Solution and Testing
To resolve the blade cracking issue, Suzlon added the following to the S88-V2
blade:
Three additional plies of fiberglass to the blades exterior in the transverse
direction. These plies extend over the entire blade surface in the transition
area.
One additional ply was added to the interior of the blade.
The new reinforced S88-V2 blade has lower stress and strain level in the
transition area, preventing cracks from forming.
Suzlon worked with Germany-based Germanischer Lloyd (GL), an
internationally-recognized wind energy certification organization, to test and
certify the V2 blades according to international standards.
Through this process Suzlon has developed a new level of blade testing for all
its blades by putting increased loads into the test process which exceed current
industry standards, raising the bar in product design and testing for the
industry as a whole.
