The site

The new wind turbines and low load diesel power station are located on farming land approximately 4 km from the small remote community of Hopetoun on the south coast of WA, which is not connected to the South West Interconnected System. Verve Energy installed a high wind-diesel system in Hopetoun in 2004 comprising of one 600 kilowatt (kW) Enercon E40 turbine and two Powercorp Low Load Diesel (LLD®) Generators. Since then Hopetoun has seen a tremendous 80 per cent load growth within two years due to town growth. To meet this demand an additional turbine and five more LLD®s were installed. These were fully commissioned in May 2007.

Technology

The Hopetoun Power System is a high-penetration wind-diesel system that combines two 600 kW Enercon E40 horizontal axis, variable speed wind turbines, with seven 320 kW LLD®s. The wind turbines do not have a gearbox - reducing maintenance and noise - and are controlled using Australian designed and built computer control technology installed at the Hopetoun Power Station which communicates with the turbines via radio. The LLD® is based on standard diesel generator technology, altered to run for sustained periods at loads as low as 5 per cent without suffering damage – achieving significant fuel savings. Compared with Verve’s earlier installed wind diesel systems, additional features which enhance its flexibility, reliability and wind energy penetration.

Energy purchase and supply

The wind turbines are expected to produce approximately two gigawatt hours (GWh) of electricity per annum - about 40 per cent of Hopetoun’s annual electricity demand. The production from the wind turbines at Hopetoun depends both on wind availability and load conditions as opposed to a wind farm connected to an extensive grid, where wind availability alone determines the production. Verve Energy sells the electricity to Horizon Power under a long-term power purchase agreement. Provisions are in place to trial biodiesel to fuel one generator. The wind farm is an accredited generator under the Mandatory Renewable Energy Target and the Green Power Scheme. The power station is connected to the Hopetoun district distribution system via five 33 kilovolt feeders, owned by Horizon Power.

Environmental impact

The wind farm is expected to save approximately 700,000 litres of diesel fuel and avoids the production of about 1,850 tonnes of greenhouse gases per annum - which equates to taking 430 cars off the road.

Success of the project to date

Analysis of the station’s performance so far confirmed the system can maximise wind penetration during both high and low wind energy periods. When the ratio of wind energy to township demand was high, the system reduced the diesel generator loading to minimum and allowed high proportions of wind energy to flow into the network. On average, the wind penetration was 85 per cent during high wind periods. On the other hand, when the ratio was low, the system allowed all wind energy to flow into the network and supplied the remaining demand with the diesel generators. The overall wind penetration for the period June to September was 37 per cent. Planned optimisation of the system should further increase the average wind penetration. The merits of the technology were recognised by it winning the 2006 WA Engineering Excellence Award (Environment Category).

Funding arrangements and acknowledgements

The project was granted $1.294 million by the Australian Government through the Renewable Remote Power Generation Program. The Program is implemented by the State’s Sustainable Energy Development Office in Western Australia. A $1.2 million grant from the Renewable Energy Development Initiative (REDI) has contributed to the development of the Hopetoun system.