GOLD Euros M-EU167 81.6-metre blade for Mitsubishi SeaAngel
German blade developer Euros shipped a test blade for the 7MW Mitsubishi SeaAngel (167-metre rotor diameter) to research institute Fraunhofer IWES in 2013. Runner up in this category last year, the firm has since received a GL design assessment certificate in June 2014, making the Euros M-EU167 the world's first 80m-plus (offshore) certified blade to pass all static and fatigue certification tests, the latter dynamic test being equivalent to 25 years of offshore operation.
In scaling-up from industry standards of 55-60 metres to 81.6 metres, the design team had to consider aspects from manufacturing to transport and logistics and long-term upkeep, all of which have been achieved.
Structurally, the blade incorporates four (2x2) load-carrying reinforcements or spar caps, each made of carbon-reinforced-epoxy-laminate, plus lightweight core-filler material designed for the aerospace industry. The blade mass comes in at a favourable 32.5 tonnes.
For manufacturing, Euros used a modular segmented mould, subdivided into root, middle and tip segments. This allows the company to serve the market with custom-made blade lengths, root-bolt diameters, and additional features on demand.
Two additional blade sets have been built: one for an onshore prototype in Scotland, the second for a floating offshore project near Fukushima in Japan.