A Moderate Solar Power System

The home is situated in the Goldsborough valley, near Cairns. Power consumption is modest, and as a result the home required a moderate solar power system. The home uses 240 volt AC appliances including fans, microwave oven, a refrigerator, a medium sized chest freezer and washing machine. Hot water is supplied by solar with an electric boost 1800watt element.

The system
The majority of electricity is generated by an array of sixteen 123 watt SHARP photovoltaic modules mounted on array frames above the equipment enclosure. This 2kW array feeds power into a battery bank consisting of four EXIDE 6 volt, 1330 amp-hour batteries via an OUTBACK Maximum Power Point Tracking Regulator.

A 2.3kw OUTBACK sinewave inverter/charger converts the extra low voltage DC electricity from the batteries to 240 volt AC electricity to power the house. This combined inverter/charger also allows the batteries to be charged from the backup generator during times of low solar input or excessive power usage.

Performance
The system has performed reliably, with the solar array providing around 90% of the energy required to run the house. The only maintenance required has been the routine topping-up of battery electrolyte levels, washing the panels when there is no rain or morning dew. The generator hasn’t been run long enough to require servicing.

System costs
The system would cost around $33,000 to install at today's prices. We chose a RAPS system because a connection to the mains grid would have been prohibitively expensive. Also, we wanted an uninterrupted bush/country view with no overhead wires as well as one less quarterly account. At the same time the solar system also allows us to do our bit for the environment.

Owner’s Comments on the Power System performance and SolarWorks Service
Since commissioning the solar system the main problems I came across in the early stages were ones that I could have fixed myself if I had taken the time to read the manual supplied by SolarWorks. Instead, I rang Nick often and he helped me understand how the system works. The following figures show generator run time 320 amp hours versus system run time 2970 amp hours for 758 days of operation. In the aftermath of Cyclone Larry we still had continuous power. We are planning an upgrade for the future.

The BCSE paid a visit in January 2007, checked the serial numbers of the solar panels, batteries and Outback equipment, and checked the overall neatness of the installation of the system. We are pleased to say they have given the system a 10 out of 10 in all the categories including visible warning signs so Thank you Nick and SolarWorks.