Page 187 - Applied Photovoltaics

x two 24 V chest type freezers (designed for maximum efficiency and using
brushless DC motors), each with two compressors and a combined capacity of
460 litres, for food, medicines and vaccines
x fluorescent 20 W lamps incorporating inverters to allow operation at 24 V dc
x a small inverter (24 V dc to 240 V ac at 50 Hz) for television, power tools, video
recorders
x mains-powered battery charger for 12 V automotive batteries
x portable, insulated shipping container.

The total system weighs approximately 6 tonnes and is transported on the back of a
truck. The first unit was installed in 1985 in the Pilbara region of Western Australia,
for the Ngurawaana community. A number of such systems are now operating in
Western Australia, the Northern Territory and South Australia. The acceptance and
performance of the units have been good, even with repeated transportation over poor
roads. The only maintenance required is monthly battery top-ups.
A smaller, 1 tonne, unit for transport on a four-wheel drive utility is also available, for
use in areas not accessible via a 10 tonne truck.
Prefabricated containerised PV-diesel systems were installed in 2004 in five remote
Western Australian indigenous communities in the Fitzroy Crossing area, each with
about 15 people (Sage & Saunders, 2004). Each system was identical, comprising:
x 6 m × 2.4 m × 2.4 m container with air conditioner
x 10 kW diesel genset
x 10 kVA single-phase inverter
x 4 kW p photovoltaic modules mounted above container
x 56 kWh battery.

9.3.2 Integrated solar home systems
Krauter (2004) describes a prototype integrated solar home system for use in rural
locations. A photovoltaic module, charge controller, battery, inverter, wiring and
support structure are all integrated and assembled by the manufacturer. This makes
installation simpler and improves reliability. The inclusion of a water tank provides
cooling for the module and, optionally, a source of hot water.
®
9.3.3 Stationpower
Queensland-based utility, Ergon Energy, has developed a PV hybrid system,
®
Stationpower , able to cater for loads from 20 to 150 kWh/day (Watt, 2004a). The
systems are modular, transportable, and can be supplied self-contained or as additions
to existing diesel generating sets. Most systems use photovoltaics, which are supplied
in one or more 2.1 kW p adjustable, steel frame bays. Wind and hydro can also be used
and the systems switch automatically between generator types. Australian made
SunGel valve-regulated lead acid gel batteries are used. One or more Power Solutions
Australia 5 kW, 120 V dc interactive inverters, with built-in battery chargers, are used
to allow synchronous operation with the diesel generator, or with other inverters, as
well as to provide remote system monitoring. Simple weatherproof plug interconnects
allow for easy replacement of components and system upgrade. Stationpower ®
systems are designed for harsh environments, with rugged construction, and dust-,

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