+ 19.01.2010 + When it comes to energy storage from large PV systems, it may soon be time for batteries to move aside.

A state-run electricity utility in Western Australia will soon start construction of what it claims are the world’s first PV-diesel hybrid systems to take advantage of flywheel technology for uninterruptible power supply.

On Dec. 11, Horizon Power announced it had signed a contract with US-headquartered SunPower Corp., beating out requests for proposals from six other companies, for more than 500 MW of solar farm trackers and modules. Horizon will use an undisclosed portion of $25 million AUD ($16.4 million USD) for the entire project to install the pair of PV tracking systems, the largest in Australia, in the remote desert region of east Pilbara.

Ingrid Ekstrom of SunPower’s press office, attributes her company’s selection to its July purchase of Solar Sales Pty Ltd., an Australian integrator and distributor. This is SunPower’s second major PV deal in Australia in the past few months. In October, it signed a contract to install a 305 kW SunPower PV system on the roof of the Crowne Plaza Hotel in Alice Springs, Northern Territory. When completed, the company claims, it will be the largest roof-mounted solar power system in Australia.

As to the solar farms, SunPower will start construction in March using its T20 single-axis trackers for a 302 MW system in Marble Bar, located 1,500 km north of Perth on the edge of the Great Sandy Desert, and a 203 MW system in Nullagine in the Little Sandy Desert, 100 km south of Marble Bar. While Horizon’s managing director, Rod Hayes, was expecting SunPower to use its 215 W monocrystalline modules with a 17.3-percent panel efficiency, SunPower’s Ekstrom says it is more likely the company will go with its 315 W module with an overall efficiency of 19.3 percent.

In addition to diesel generators with 1,280 kW of capacity in Marble Bar and 960 kW in Nullagine for ensuring power reliability and stability, at each site Horizon is putting in a 500 kW flywheel and inverter unit known as the PowerStore, developed for commercial applications by the Australian company Powercorp. While the concept of storing PV-generated electricity for backup using flywheels has been around for decades, this appears to be the first application for a commercial solar installation.

PHOTON International 2010