Located in the suburb of Bruce in Canberra, it would seem that Radford College was purpose-built for a solar installation. The school stands on the side of a hill, and its sloping roofs lie within 1 per cent of the optimum sun-catching orientation.
The 7 kilowatt (kW) solar photovoltaic (PV) power system comprises 52 high efficiency 135 watt multi-crystalline PV solar modules, manufactured by Kyocera. The array is mounted on solar-specific mounting equipment across 54 square metres of roof space, atop a mathematics building and electrical switchboard room, adjacent to the main turning circle.
Not only is the slope of the roofing ideal for capturing of the sun’s rays, it also means that the installation is seen from far and wide by the school community.
“The panels are very visually available,” says the school’s Facilities Manager Robert Harris.
Article continues below…The array is connected to two SMA inverters via USE2 rated DC solar cabling, which connect to the electricity network via a digital gross production meter. The panels are ideally located above the main sub-station, which has kept down connection costs, explains Mr Harris.
The inverters are also connected to the internet via a smart meter system which will automatically upload system data to a dedicated website, where it will soon be used within the school science curriculum.
The size of the school meant that it was eligible for $100,000 through NSS, $72,000 of which went towards the solar installation and the remainder to additional water tanks. These additions complement the school’s existing sustainability set-up, including solar hot water systems, a recycling program, and a water recycling system.
The NSS offers grants of $50,000, and up to $10,000 for larger schools, to install solar and other renewable power systems; solar hot water systems; rainwater tanks; and a range of energy efficiency measures.
Autonomous Energy, which installed the system, estimates that the return on investment will be approximately 7.7 percent, which includes returns through the Australian Capital Territory (ACT) feed-in tariff.
“There’s a very quick pay-back period, considering that for the summer months, when there is plenty of sun and students are on holiday, there is opportunity to benefit from the feed-in tariff,” says Mr Harris.
With an estimated annual energy production of 11,085 kW hours, Radford’s system will reduce the school’s emissions by an estimated 12 tonne of C02 each year.
