windfarm

A windfarm is a collection of windmills that pool their output towards a common 'consumer', usually the power grid.

Windfarms seem to pop up all over the place ! This is fantastic news, because windpower is one of the cleanest and most abundant forms of energy available to us. Typical windfarms consist of several 10's or sometimes even several 100's of machines that are connected to each other and to a switching station.

Turbines of all sizes can be connected together, some use 'synchronous' coupling where all the machines that contribute to the output power are AC coupled so they all rotate at exactly the same speed, which in turn is dictated by the frequency at which the grid operates (60 Hz in the US and Japan, 50 Hz elsewhere).

Windfarms pose unique problems to their designers and operators. Windmills placed close to each other affect each other aerodynamically, so a spacing regime has to be developed to minimize those effects.

Also, because windmills operate in remote locations (the 'best' winds are usually not found near large population centers, which is where the highest consumption takes place!) transmission issues are another hard nut to crack.

Another issue seems to be the 'reactance' presented to the local - small - powergrid lines, when changing load or coming online/going offline. The solutions here involve specially developed ''grid stabilizer' units, pretty much the only time ever that I've heard the term superconductor and windmill used in the same breath !

Then there is maintenance, which for a remote park can be a costly affair.

In spite of all these stumbling blocks windparks are getting more and more common.