How wind farms work
Wind turbines convert the energy of the wind into electricity. The turbine blades are turned slowly by the wind, and this rotation spins a generator to produce electricity. The electricity travels through transformers and a transmission line into the local electricity network for distribution to consumers.
Almost all commercial wind turbines producing electricity consist of three blades connected to a hub that rotates around a horizontal axis. The hub is connected to the generator either directly or via a gearbox, which is located inside the nacelle, the large part at the top of the tower.
Turbines with electronic power converter technology, such as those at Mt Millar and Windy Hill, do not have gearboxes. Instead, the electricity generated by the generator is rectified from AC into DC before being inverted back to AC suitable for distribution. The generated electricity passes through cables from the nacelle to the base of the tower. Here it is stepped up to high voltage in a generator transformer for supply to the transmission system.
Each of the turbines connects to the transmission system via the on site substation.
Wind turbines start operating at wind speeds of 2.5 metres per second (around 9 kilometres per hour) and reach maximum power output at around 13.5 metres per second (around 49 kilometres per hour). At very high wind speeds, such as gale force winds (34 metres per second or 122 kilometres per hour), wind turbines shut down to avoid damage to the equipment.
The blades rotate at 6 rpm in low wind conditions and 21.5 rpm at higher wind speeds to maximise energy production.
For more information about wind farms, please visit www.windfarms.net.au