Cadmium telluride (CdTe) thin-film photovoltaic (PV) module maker First Solar Inc of Tempe, AZ, USA, international mining group Rio Tinto and the Australian Renewable Energy Agency (ARENA) have announced that Australia's first commercial diesel displacement solar plant has begun commercial operation at a remote mine. The Weipa Solar Plant will generate electricity for Rio Tinto's Weipa bauxite mine, processing facilities and township on the Western Cape York Peninsula in Queensland.
"This power purchase arrangement [PPA] is an opportunity to trial the introduction of an alternative power source such as a solar plant into a remote electrical network like the one here in Weipa," says Gareth Manderson, Rio Tinto's general manager, Weipa Operations. "At peak output, the 1.7MW capacity solar plant has the capacity to generate sufficient electricity to support up to 20% of the township's daytime electricity demand," hr adds. "We expect the energy from the solar plant will help reduce the diesel usage at Weipa's power stations and save up to 600,000 litres of diesel each year. This will reduce Weipa's greenhouse-gas emissions by around 1600 tonnes per year, equivalent to removing around 700 cars."
The solar plant should produce an average of 2800MW-hr of electricity per year. The electricity from the 18,000 First Solar PV modules that have been connected to Rio Tinto's existing mini-grid will be purchased by Rio Tinto under a 15-year power purchase agreement. First Solar's FuelSmart solutions combine PV generation with a fossil fuel engine generator to provide optimal fuel savings while maintaining system reliability.
"It is already widely acknowledged that solar electricity is typically cheaper than diesel-powered electricity, particularly in remote locations," comments Jack Curtis, First Solar's regional manager for Asia Pacific. "The significance of the Weipa Solar Plant is that it provides the opportunity to demonstrate that PV-diesel hybrid projects can also be as reliable as stand-alone diesel-powered generation," he adds.
"In recent years, attention has been focused on the technical challenges of high-penetration PV-diesel hybrids," continues Curtis. "At the Weipa Solar Plant, First Solar is seeking to deliver a reliable electricity supply without diverting capital costs away from Rio Tinto's critical mine operations. Proving this commercial model has the potential to be a watershed moment for the diesel hybrid application globally," he adds.
"This is the first time a remote Australian mining operation has been supplied with power from solar PV on such a scale," notes ARENA's CEO Ivor Frischknecht. "The success of phase one is set to create a precedent for industry by demonstrating that solar PV is a viable option for powering off-grid locations, like mine sites, in Australia," he adds.
ARENA provided an initial $3.5m for this early-mover project, and up to $7.8m is available for the second phase. "Similar ARENA-supported projects now underway, or in the pipeline, will build on this landmark project to further prove the reliability of integrating renewable energy solutions in off-grid locations while helping to drive down costs and the need for subsidy," Frischknecht says.
Contingent on the success of phase one, the project partners have the option of entering into a second phase that would include a storage component. At 6.7MW, the expanded plant would have the potential to save about 2,300,000 litres of diesel on average each year, reducing Weipa's greenhouse-gas emissions by around 6100 tonnes per year.
