Lake Lefroy Alternative Energy project

Harnessing wind power in Australia

A new project at Gold Fields’ St Ives operation in the Australasia Region looks set to harness wind power as a renewable energy source for the mine. This comes at a critical time for the operation, which currently sources power through from BHP Billiton, an agreement that expires in 2014. The company is in negotiations to extend the contract but BHP Billiton is unable to guarantee uninterrupted power for any requirements that the mine may have over and above the current 20MW/year. Gold Fields is ready to bring new underground mines into production, but these will require up to 40MW so the pressure is on to find alternative sources of energy.

Prior to committing to a large capital investment in wind turbines, Gold Fields has followed industry best-practice by conducting a two-year targeted wind survey to establish whether wind speeds in the area surrounding St Ives will be sufficient to provide the additional power requirements. Typically, average wind speeds above 4 metres per second (14.4km/h) are needed to turn a large scale wind turbine.

In 2009  St Ives management commissioned the installation of a 10m-high mast near the centre of Lake Lefroy. Wind speed data is recorded every 15 minutes and captured by a data collection system. The results look promising. Data gathered up to now, together with regional wind maps, indicate that the wind resource exceeds the minimum requirement for turning large turbines.