GOLD Siemens SWT-3.3-130
This is, in essence, the latest evolution of the direct-drive 3MW SWT-3.0-101 turbine introduced in 2009. The SWT-3.3-130 has been developed specifically for the midand low-wind, land-constrained German market, and a prototype has been installed in 2015.
Data from the product launch indicates that it is expected to generate around 16GWh annually at sites with 8.5 metres per second (m/s) wind speed, and around 10GWh at 6.5m/s (both average wind speeds at hub height).
A notable feature is the fitment of the latest in-house designed load-reducing aero-elastically tailored B63 blades. The extra 100kW in power rating over the previous 3.2MW model, and especially the use of a much larger, slower-turning rotor, necessitated a substantial upgrade to the generator and the complete nacelle.
The technical modifications include a generator that is now directly air-cooled, eliminating the cooling radiator used in the D3 platform, together with a stronger bedframe with upgraded yaw system, a new hub and a larger single main bearing.
Enhancements of the electrical and electronic systems include advanced noise control, together with grid-inertia response and weak-grid support, plus a built-in capability to provide reactive power in conditions with no wind.
SILVER Nordex N131/3000
This 3MW low-wind model, the first prototype of which started operating in early 2015, completed Nordex's Delta platform range. Its 131-metre rotor diameter represented a new standard for the 3MW IEC Class III sector. A 3.3MW variant — like the Siemens SWT-3.3-130 model aimed at the German market — can be specified with a hub height of 164 metres.
Key features include a high-speed modular drivetrain layout with three-point gearbox support and DFIG. The most innovative component is the in-house developed lightweight 64.4-metre rotor blade that incorporates carbon in the load-carrying structure. It is characterised by its slender shape towards the blade tip and a maximum chord with flat-back airfoil that extends towards the root to maximise energy capture and reduce blade loading.
BRONZE Vestas V126-3.45
This latest upgrade for IEC IIA sites— announced in 2015 — is expected to be a strong contender in medium-wind markets when it becomes available at end 2016.
The largely evolutionary development of the 3MW platform involves four model variants, including the V126. The rated power has been increased from 3MW to 3.45MW, and it has been simultaneously upgraded from low-speed IIIA to medium-speed IIA wind sites. A low-noise version has also been made available.
Vestas' 3MW onshore platform was introduced in 2010, initially comprising just one model with a 112-metre rotor diameter. All variants feature a non-integrated high-speed drivetrain with three-point gearbox support.
In 2013 Vestas boosted power rating to 3.3MW, switching from PMG to induction generators at the same time.