Hybrid power lifts Bar

Sunday Times
Sunday 22/8/2010 Page: 69

Clean Green married Dirty Old Diesel on Friday as Marble Bar, the hottest town in Australia, became home to the world's first hybrid (solar-cum-diesel) power station that will harness harsh light to meet 190 residents' energy needs. A second station will be opened in the neighbouring Pilbara town of Nullagine, about 88km from Marble Bar, featuring reduced carbon emission footprint criteria to replace noisy and ageing diesel stations. The combined cost of the two power stations is $30 million, with $4.9 million of Federal Government funding assisting the 1350-solar panel Marble Bar station, which cost $16 million, and the 900-panel Nullagine project.

Rod Hayes, managing director of Horizon Energy, said that during midsummer peak load days, air conditioner-driven energy demand would surge to 600kW in Marble Bar. Up to 90% of daylight power could be delivered by the solar component and, on average, 65% of daytime power and 30% at all times would be solar-sourced. Mr Hayes said the power stations, which feature rotating panels that track the sun, would generate 1GW of renewable energy a year, saving 1100 tonnes of greenhouse gas emissions by reducing diesel usage 35 to 45%.

"The critical thing is that the system does not store energy using batteries, which are expensive and require enormous maintenance", Mr Hayes said. "We have created a hybrid system that is unique, a first of a kind using inertial storage. "So when photovoltaic panels have a drop in output, for instance due to cloud cover, the inertial storage is released during the transition as the diesel comes up to speed".

He said the new stations, relying only on one power station manager to oversee operations during the day, would also be cost effective on manpower. He said the old Marble Bar diesel power station was well past its sell-by date and Horizon Power had looked at a replacement that would be a lot more clever. "If you look around Marble Bar there is not a cloud in the sky, so the solar resource is fantastic", Mr Hayes said.

The combined CO2, emission reduction of both stations was the equivalent of 400,000 litres of diesel and 6000 cars, he said. Two diesel tanks holding 140,000 litres at Marble Bar would supply about a month's diesel. The plant was designed to carry at least two weeks' supply in case it was cut off through flooding. Mr Hayes said diesel was preferred to gas as it was not economically viable to divert gas supplies a few hundred kilometres off existing routes and build support infrastructure. He said although the project was capital-intensive up front, calculated savings over 25 years from diesel and carbon emission offsets were 20 to 30% over a diesel only station.

Horizon Energy, whose niche market is small towns, believes the technological threshold of the solar-diesel hybrid would be about 10MW, before it would have to start relying on small gas engines. The Marble Bar station was officially opened by Mines and Petroleum Minister Norman Moore, who believes the technology can be expanded to mining operations currently relying on freestanding diesel stations. "I think the technology has got tremendous potential in WA", he said. "Not just in mining but a lot of small towns where you can look at something similar to (Marble Bar) provided the cost is at a level which is comparable to other sources of power".