First wind turbines with polyurethanes from Covestro

COVESTRO has put into operation its first wind turbines with wind blades made using polyurethane infusion resin. The successful installation marks the latest milestone in Covestro’s mission to commercialise polyurethane infusion resin as a key material that will help to shape the new generation of longer, stronger wind blades demanded by the wind power industry.

The spar cap and shear web of the 55.2 metre-long blades for the 2MW wind turbine were fabricated with polyurethane infusion resin from Covestro. Covestro developed the polyurethane infusion resin solution for wind blade manufacturing to meet the growing demand for taller, longer wind blade designs that can stand up to the stresses that taller turbines can face. The development process involved the participation of Covestro R&D teams around the world and is enabled by close collaboration along the value chain including blade manufacturers, turbine manufacturers, glass-fibre producers, machine suppliers and blade designers.

“The successful installation of the pilot turbine in Northeast China is recognition of the strengths of our polyurethane infusion resin and demonstrates that it is ready for use in operational wind blades. We hope that this gives a strong signal to our industry partners to manufacture and install longer, stronger wind blades,” said Julien Guiu, Vice President Industrial Marketing APAC, Polyurethanes Business Unit, Covestro.

New turbine blades must undergo extensive independent testing to obtain all relevant certificates. To meet the demand for wind blades that can operate for long periods in harsh conditions, Covestro thoroughly tested the performance of the wind blades used in the turbines. They successfully passed the static test and fatigue tests both edgewise and flapwise.

Wind turbine rotor blades are typically made out of fibreglass reinforced resin through vacuum infusion technology. The successful use of polyurethane composite for manufacturing large-scale wind turbine rotor blades suggests that the polyurethane resin itself features superior mechanical properties and anti-fatigue performance. There are also benefits to production processes in the wind blade factory, with a faster curing process and better processing properties that can deliver higher levels of productivity.

In addition to the installation of its own commissioned wind blades in Northeast China, Covestro also partnered with one of China’s leading wind turbine manufacturers to develop another 2.2MW turbine with 59.5 metre-long blades, whose spar cap, shear web and blade root were fabricated with Covestro’s polyurethane infusion resin. The turbine has been installed in South Central China.