Ebert, who admits to being "very happy," says that two 230 kW E30 Enercon wind turbines will join the existing E30 installed near the town in June 1998 to augment the town's diesel generation. The turbines are part of the utility's drive to develop a high penetration wind system for diesel mini-grids. The project is being developed jointly with Australian remote area power specialist Powercorp. The potential to market the technical expertise to the "reasonable" worldwide market for wind-diesel systems was a major factor in winning the federal support, says Ebert. The need to provide a reliable and rugged system for remote areas "is not that easy to do" he adds.
The existing E30 turbine on its 50 meter tower has been generating about 5% above expectations, supplying an average of 22% of the town's average load of 600 kilowatts. The turbine, however, can "quite happily" generate 50% of the load during some periods of high winds and high loads. The strategy has been to limit the wind output when the diesel output drops to 40% of its rated capacity. Wind energy is "dumped" through a combination of blade pitching and inverter control, a strategy Ebert believes is a first. As Denham is in a cyclone area, the existing and new turbines are designed to withstand a 1-in-1000 years gust of 63 m/s.
In addition to the two additional turbines, the new project will incorporate energy storage that will "probably" be in the form of lead-acid batteries. "The storage will give us the capability to run the town entirely on wind and turn the diesel generators off completely," says Ebert, adding that the average penetration of wind should be about 70%. He expects the turbines to be installed by June or July with the controls and energy storage systems completed by the end of 1999.
The local government has been supportive and views the project as a good image for a town that is heavily dependent on tourism. Western Power has used an Enercon standard light blue colour for the tower and turbine which "really suits the environment" and blends in much more than the white turbines at the state's other wind farm in Esperence, according to Ebert. There has been one "amusing" complaint though. "A fisherman complained he couldn't see the existing turbine to use as a landmark," quips Ebert.