LOCATION

The power system illustrated was installed at the Watarru Aboriginal Community in the Pitjatjantjara Lands of South Australia in November 1992. The capital funding was provided by Aboriginal and Torres Strait Islander Commission (ATSIC). The overall project design and documentation was a co-operative effort between the South Australian Department of State Aboriginal Affairs, ATSIC and Appropriate Energy Power Corporation Pty Ltd, Western Australia (SPC).

THE SYSTEM

The contract was awarded and the project managed by the SA Department of Aboriginal Affairs. The system was designed to suit a fluctuating population of between 30 - 90 people, including a school building and a bore water pumping facility. The Remote Area Power System (RAPS) was constructed by SPC. The system provides a 415V three-phase electrical supply, reticulated to each house as a 240V supply.

The system receives electrical energy from two Appropriate Energy model S20000 wind turbines and 10 x 60W solar panels and converts this free energy into 240V power for domestic use. The collective output of the two wind turbines is approximately 56kWh (= 56 units of energy) per day based on average wind speeds at the location, which is South Central Australia, latitude 27º South, longitude 130º East. The collective output of the solar panels is approx. 4kWh/day.

The wind turbines and the solar array generate 110V DC power through a control panel into a deep cycle battery bank. This DC power is inverted through a three-phase 30kVA interactive inverter to 240V AC power into the load demand to give continuous 24 hour power.

A diesel generator is included in the system as standby power to keep the batteries charged during periods of wind drought to ensure the 24-hour reliability of the RAPS.

The generator is powered by a three cylinder engine producing three-phase AC power which connects in parallel with the output of the inverter. During the engine run periods, the inverter software apportions load to ensure a safe operating range from the batteries.

The RAPS is fitted with monitoring equipment which is partly funded by the SA State Energy Research Advisory Council (SENRAC). The collected data will provide valuable information to RAPS designers. The grant application was supported by the Electricity Trust of South Australia (ETSA). This monitoring will give details of wind speed, power supplied by the wind turbines, power input by the diesel generator, the load profile and load consumption. Project engineers who have the task of preparing remote power systems, now have a working example on which to base their designs.

MAINTENANCE

The Appropriate Energy wind turbine requires an annual inspection and service by a certified and trained dealer or installer. The process should normally take approximately one hour to complete. Bearings need to be changed once every five years and would take less than a day to carry out. The gel-cell batteries require no maintenance.