From Dr A Jagadeesh, Nayudamma Centre for Development Alternatives, Nellore, Andhra Pradesh, India
PERFORMANCE AND SIZE
The auther is drawing atttention to the importance of ensuring an optimum match between tower height, rotor diameter, generator size and the wind frequency distribution. This advice is based on the fact that manufacturers have increased generator size without actually increasing the rotor diameter in the same ratio.
I read with interest the excellent article, Jumbos and the Square Cube Law (“uåX˜äŠÊ˜·³Ç, April 1995). An interesting point emerged from a study of the 1.18 MW Mandvi Wind Farm in Gujarat. Commissioned in 1986, it has machines with three capacities: 55 kW, 110 kW and 250 kW. The performance of these machines revealed that the output per kW of installed capacity decreased with machine size, whereas the output per square metre of rotor swept area increases with machine size. This clearly indicates that manufacturers have increased generator size without actually increasing the rotor diameter in the same ratio. This only shows that when choosing machine specifications, care should be taken to ensure an optimum match between tower height, rotor diameter, generator size and the wind frequency distribution.