First Solar, Rio Tinto and the Australian Renewable Energy Agency (ARENA) announced in late September that Australia’s first commercial diesel displacement solar plant successfully started 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, Australia.

Electricity from 18,000 photovoltaic panels installed at Weipa will be purchased by Rio TInto under a 15-year agreement.Electricity from 18,000 photovoltaic panels installed at Weipa will be purchased by Rio TInto under a 15-year agreement.

Rio Tinto’s general manager of Weipa operations, Gareth Manderson, said, “This power purchase arrangement 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. At peak output, the 1.7-megawatt (MW) capacity solar plant has the capacity to generate sufficient electricity to support up to 20% of the township’s daytime electricity demand. 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 liters of diesel each year. This will reduce Weipa’s greenhouse gas emissions by around 1,600 metric tons (mt) per year, equivalent to removing around 700 cars.”

The solar plant is expected to produce an average of 2,800 MW hours of electricity per year. The electricity from the 18,000 advanced First Solar photovoltaic (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,” said Jack Curtis, First Solar regional manager for the Asia-Pacific region. “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.”

“In recent years, attention has been focused on the technical challenges of high-penetration PV-diesel hybrids. 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,” said Curtis.

“This is the first time a remote Australian mining operation has been supplied with power from solar PV on such a scale. 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,” ARENA CEO Ivor Frischknecht said. “ARENA was pleased to provide an initial $3.5 million for this early mover project and up to $7.8 million is available for the second phase. Similar ARENA-supported projects now under way, 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.”

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 6.7 MW, the expanded plant would have the potential to save approximately 2,300,000 liters of diesel on average each year, reducing Weipa’s greenhouse gas emissions by around 6,100 mt per year.