Bundaberg Christian College, Ashfield, Queensland

WINNERS: Dimitar Iliev and Kurt Elvery for GEM Energy

Already entirely self-sufficient for its water, the Bundaberg Christian College felt it was time to generate its own electricity. Of course, it’s never that easy. “Due to large seasonal variation in energy usage it’s impossible to design a system that will allow for 100% self-sufficiency without over-capitalizing,” Dimitar Iliev and Kurt Elvery of GEM Energy told EcoGeneration.

Many schools in regional Queensland will see increases in consumption during summer months of 300% purely based on air-conditioning loads, and once that was explained to the client Iliev and Elvery were able to create a set of achievable objectives.

abb-inverters_small“The school had never explored solar in the past and were a clean slate which allowed us to educate them on the need to become as energy efficient as possible before venturing into solar and storage,” they said.

First, energy consumption was cut 20% by replacing all fluoro lights with LED, putting timers on hot water systems and changing the stand-by programming on the computers. The savings made by going with a smaller solar system and battery system more than covered the cost of the LED refit and other initiatives.

“The system is offsetting the night time consumption of the school as well as managing peak demand,” the GEM team said. “It is also a great educational tool which the kids love to talk about.”

One challenge was finding products capable of supporting such a large battery system. “Against everyone’s expectations, most major inverter manufactures told us they could not support such a large AC-coupled PV array with batteries,” they said. “Only by working closely with Selectronic we were able to customer design a solution to our customers’ requirements.”

And what was the best part of the job? “It’s definitely satisfying having been able to design and build a battery system that even the engineers of major battery manufactures told us it would not be possible.”


Project name: Bundaberg Christian College

Location: Ashfield, Queensland

Owner: Bundaberg Christian College

Developer/contractor: GEM Energy Australia

Capacity: 194kW of solar PV and 252kWh usable energy storage

Commissioned when: March 2016

Key equipment installed: 732 x Q-Cells Q.PRO G4.1 265w Panels, 3 x ABB TRIO 27.6 TL-OUTD-400, 5 x ABB TRIO 20.0 TL-OUTD-400, 3 x Selectronic SPLC 1202, 30 x Hitachi LL2000AS8 battery modules

Energy usage: 370MWh per year

Expected payback period: about 7 years


The PV and battery system at Bundaberg Christian College shows beneficial outcomes from close and well-informed interaction between the system designer/installer and the client. Discussion resulted in significant load reductions before design and implementation of a system including redesign of a commercial inverter. The success of the project has led to heightened interest from other schools in undertaking similar improvements.

Australian Centre for Advanced Photovoltaics chief operating officer Dr Richard Corkish and Envirotecture director Dick Clarke.