MEDAL WINNERSGOLD Goldwind GW150-2.8MW
The Chinese manufacturer’s latest direct-drive model for IEC S ultra-low-wind conditions (6m/s) boasts a specific power rating of only 158W/m2.
According to Goldwind, it delivers 2,712 full-load hours at 5.5m/s, which translates to an annual energy production (AEP) of 6,780MWh.
The GW150-2.8MW is the latest addition to the firm’s 2.5S platform, which had a cumulative order backlog of around 6.4GW in Q1 2019.
Standard technology features of the compact drivetrain include a fully enclosed air-cooled in-house PMG with a nacelle-integrated heat exchanger and a single main bearing supporting both the generator and turbine rotors.
Unique to Goldwind, apart from Vensys, in the direct-drive sector is a low-maintenance toothed-belt drive for the individual pitch systems of each rotor blade.
Leading Chinese OEMs are increasingly combining a supersize rotor with a modest rating as they search for optimised configurations capable of fully exploiting the potential of low- and ultra-low wind speed markets.
These include large parts of China and other areas in the Asia-Pacific region, notably India. The GW150-2.8MW is initially focused on China, but may become available in other markets in the near future.
SILVER Envision EN156-3.3
Aimed at medium-wind speed conditions, the EN156-3.3 has a specific power rating of 173W/m2, which Envision says makes it a strong contender for zero-subsidy projects in north and south-west China.
A key characteristic is the cut-out at 25m/s wind speed with a re-cut-in at 20m/s, a control strategy to minimise standstill during gusty conditions and enhance generation at high wind speeds.
The latest 3MW platform has evolved from Envision’s mature 2MW series, comprising a drivetrain layout with a three-point gearbox support and DFIG in 50Hz/60Hz configurations.
A particularly innovative feature is three-level technology for the electrical power conversion. The increased generator output voltage — 690-950V — helps reduce transport-cable power loss down the tower.
BRONZE Vestas V120-2.2MW
Originally marketed with a 2.0MW rating and aimed at low- to medium-wind sites with high turbulence, Vestas’ V120 continues to be a top-seller in North America and other key markets.
The platform’s history dates back to 2000 with the launch of the V80-2.0MW and the global track record now encompasses over 23,000 units across 46 countries, making it the widest-applied turbine of this century.
All 2MW variants feature a classic non-integrated high-speed drivetrain with four-point gearbox support, a three-stage gearbox with one planetary stage and DFIG.
Particularly noteworthy is the combination of increased performance with a minimum increase in mass, enabling easy and economical transportation. The blade design is clever, too.