Wind turbines for generating industrial scale electricity are very large structures. The amount of power that it is possible to generate depends on the area of the disk that is swept by the rotating turbine blades.

Power output also depends on the quality of the air passing through the turbine blades. The air quality is usually better, less turbulent, higher up. So modern wind turbines are built with the biggest blades that it is practical to operate on the tallest towers.

The pictures shown above show structures of about the same size as those planned for Puketiro. The planed turbines would provide a maximum of 3,000 Kilowatts (3 Megawatts) output which means blades sweeping through a 90 meter disk of air and towers about 130 meters high (note that the average output of wind turbines in NZ is less than 40% of the rated maximum, so a 3,000 Kilowatt turbine produces on average under 1,200 Kilowatts).

To put this in visual context, the turbine blades at Puketiro would 30 meters larger than the wingspan of a boeing 747 jumbo jet (the schematic below shows a much smaller turbine).

The size of wind turbines continues to increase as construction techniques improve. Developers will typically try to install the largest turbines that they are permitted to install and that the limitations of the terrain will enable to be transported to the site.   Much of the difficulty of erecting large turbines is finding or creating suitable routes to move them to the site, as wide roads are needed.  Currently, movement by air is not possible due to the huge size and weight of each component. This may change in the future, in which case it will be possible to install much larger turbines on land. As turbines reach the end of their life, or are no longer economically maintainable (which in some case could be within a few years), the operators may replace them with larger machines.

Above picture is of Sterling Castle in Scotland with turbines in background of a similar size to those planned for Puketiro and other sites in NZ.