Australian solar power generators have boosted output by 46%, by upgrading to multi-junction III-V/germanium solar cells, which are normally reserved for space.

Three power stations in the Northern Territory are involved, originally producing 720kW from parabolically concentrated (500x ) sunlight.

In all, there are 30 14m wide mirrors each with a 30% efficient water-cooled cell that now delivers 35kW, boosting total output to over 1MW - replacing 420,000 litres of diesel oil per year, claims German power chip maker Semikron which supplied the stations’ power converters.

The solar cells are thought to be GaInP/GaAs/Ge types from California’s Spectrolab which are normally used in space. They replace silicon-based cells and have an area of 0.23m sq.

Each dish, made by Australian firm Solar Systems, has 112 mirrors, and each mirror is nearly 1.2m sq. in area. Multiple dishes share common cooling, controls and electrical subsystems.

On the power side, dishes are wired in pairs, delivering 260Vdc into inverters using Semikron’s 600V water-cooled SKiiP power stages.

"By upgrading the SKiiP modules, it was a simple matter to upgrade the inverters to handle the increased power from the generators," said the firm.

SKiiP modules include gate drive, power half bridges, current sensors, protection and water cooling, all in a pressure-contact housing.

The Australian state of Victoria is planning a 154MW station, with a target efficiency of 40%. "This will require voltages to be increased to a more efficient 600-700Vdc, using 1,200V IGBT chips in the inverters," said Semikron.