Six years after installing its first 3MW AW3000 in Spain, Acciona Windpower has produced the AW125/3000, a low-wind version for IEC IIIA sites. After a slow start for turbine commercialisation and manufacturing ramp-up, Baron reported record global sales during the past 12 months, amounting to more than 500 turbines.
By the end of 2013 AW3000’ combined capacity was around 175MW with another 800MW planned in 2014. Around 120MW of the current installed base is for the AW116/3000, spread over Spain, the US, Canada, Poland and Brazil.
High-speed
The AW3000 comprises a "conventional" non-integrated high-speed geared drivetrain with a main shaft supported by two bearings, and a 12kV doubly-fed induction generator. According to Baron, this voltage level, compared with common much lower levels, might eliminate the need for a medium-voltage step-up transformer for wind projects located close to the project substation. He estimated lifecycle-based net present value (NPN) benefits to be generally in the EUR30,000-50,000/MW range, with significant impact on project returns.
The use of concrete is really successful in markets with local-content rules such as Brazil, where steel is also expensive. In the US, Acciona has had success with the shorter steel tower.
Shear
Speaking about tower selection, Baron said: "An interesting steel tower variant is a four-section design with a 87.5 metre hub height, which offers favourable economics, especially for sites with lower wind-shear values. Our tower portfolio now also includes a 120-metre steel tower option for the AW116/3000 and the new AW125/3000."
When asked about taller concrete towers and/or a switching to concrete-steel towers for greater hub heights, Baron said: "We are able to produce taller tower concrete towers but haven’t fully developed this option yet. Wet are particularly interested in developing this for northern Europe and Scandinavia. Tall concrete-steel hybrid towers is another option we are looking at."
