The wind industry has long worried that shortage of main components -- particularly gearboxes and bearings requiring high quality steel, as well as castings -- would limit growth for the foreseeable future. But BTM's findings suggest that an aggressive ramp-up by both established and new suppliers is loosening bottlenecks for all but a few components.
BTM notes that top manufacturers Vestas, Suzlon and Nordex are already beefing up their worldwide in-house production capacity of turbine blades and highlights expanded capacity by independent blade companies. There has also been increased global production capacity for power converters and transformers, castings and forged items -- particularly in China and South Korea. Through 2012, BTM foresees a surplus of electric generators, power converters, power transformers, blades and -- by a thinner margin -- gearboxes.
Still, the consultancy stresses that gearbox availability will hinge on boosted output of bearings. It estimates that only 30%-40% of potential suppliers are able to provide large bearings for generators, rotor shafts and gearboxes. The most vexing shortage is for pitch slewing bearings, and although suppliers SKF and Schaeffler are rapidly raising production capacity and new suppliers are coming online, BTM expects no easing "within the next two years." The situation is exacerbated by scarcity of high quality metal alloys used in the bearing rings.
There will be just enough casting capacity this year, but supply will tighten toward 2012 unless manufacturers ramp up capacity, BTM says. It adds that producers of forgings are often located far from customers, resulting in supply imbalance: in 2012, BTM expects demand to drastically outpace supply in Europe and the Americas, with the reverse true in China and South Korea. Meanwhile, many suppliers currently struggle to deliver drive shafts for turbines larger than 3 MW.