Envision Energy has connected a 1.5MW turbine for ultra-low wind-speed areas to the grid in Lai'an Wind Farm, Anhui province. Both are designed for class-IV wind-resource areas where the annual average wind speed ranges from 5.5-6.5 metres per second (m/s).
The turbine is notable in that it is the world's first 1.5MW turbine with a 93-metre rotor. The previous record for a 1.5MW turbine - of 87 metres - was also held by Envision.
This marks the biggest breakthrough for the firm, in terms of tapping ultra low wind speed areas, since it put forward the world's first 1.5MW turbine with an 87-metre rotor in 2009.
Goldwind has also launched a GW93/1500 a new ultra-low wind speed direct-drive version of its 1.5MW turbine. The machine also a 93-metre rotor diameter, uses a permanent magnet generator and a full-power converter.
According to Goldwind, the GW93/1500 series can generate power of more than 2,000 standard hours per year based on an annual average wind speed of 5.5m/s.
The low and ultra-low wind-speed areas, totalling 68% of China's wind-resource areas, are normally in close proximity to urban areas with strong grid capacity.
China will have 20GW wind turbines installed in low wind-speed areas, out of the 100GW target for 2015. Sinovel said it is able to mass produce SL1500/81 and SL1500/89 low wind-speed turbines.