Turbines of the year - Turbines 2.1 - 3.5MW

WORLDWIDE: The utility class forms the main battleground for the world's leading turbine manufacturers

Industry standard… Nordex’s low-wind N177/2400 has stolen a march on the competition


GOLD Nordex N117/2400

The 2.4MW Nordex N117 low-wind model was introduced in 2011 and immediately established a wind industry benchmark. Its mid-2012 commercial ramp-up pushed it perhaps two years ahead of the competition, boosting the company's market share in Germany from around 4% in the first half of 2012 to around 11% a year later.

Technically, the N117 builds on the 2.5MW Gamma platform, the origins of which dates back to the N80/2500 Alpha series of 2000. The combination of 2.4MW rated power and a 117-metre rotor diameter provides a specific power rating of only 223W/m2.

A key feature is the slender in-house-developed rotor blade with carbon fibres incorporated in the load-carrying main girders for exceptional stiffness with low mass. The blade weighs less than 11 tonnes.

Nordex focused on maximising yield levels at inland sites with average wind speeds at hub heights of 6-6.5m/s. The N117/2400 can produce more than 3,500 full-load hours (40% capacity factor) under these conditions.

The turbine comes with tubular steel and concrete-steel hybrid towers and hub heights up to 141 metres.

This configuration enables the development of many inland and forested sites that only a decade ago were not considered viable for wind-power.

SILVER Wind to Energy W2E-120/3fc

German engineering consultancy W2E initially developed this 3MW turbine as the Fuhrländer FL3000. Following that company's insolvency in 2012, W2E took over and finished the work, renaming the turbine as the W2E-120/3fc.

The key innovation in this completed model is the combination of W2E's patented Larus Compact with Winergy's medium-speed HybridDrive in a compact flanged drive system solution.

Larus Compact comprises a single rotor bearing and a large-diameter shaft coupling that transmits rotor torque to the flanged HybridDrive via an annular array of flexible elastomer elements. Rotor-bending moments are led directly via the rotor bearing and main carrier into the tower.

Winergy claims total system conversion efficiency (gearbox plus generator) to exceed 96.5%. Germany's environment ministry provided financial support to W2E in recognition of the innovative nature of the project.

BRONZE Enercon E-101

The 3MW E-101 builds on Enercon's long experience with direct-drive technology. The company has built 21,500 direct-drive turbines ranging in capacity from the minuscule (30kW) to the mighty (7.5MW). The E101 turbine introduced Enercon's latest thinking on drivetrain technology — a new water-cooled electrically excited synchronous generator, a principle that does not require rare earth metals.

Enercon built an advanced multi-storey facility to manufacture the E-101's blades. The automated production processes, in which unfinished blades in mobile mould vehicles move along pre-determined stations, was derived from Enercon's advanced foundry developed in-house.

The E-101 comes with industry-leading hub heights up to 149 metres. The in-house prefabricated hybrid concrete-steel towers have already been applied in thousands of Enercon turbines. A 2.5MW low-wind E-115 sister model supplements the E-101.

medium turbines shortlist

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