Solar Powered Pump – Princess Hills (Girringun) National Park

June 2021

Queensland Parks and Wildlife Services Atherton were experiencing problems with their water supply in the Princess Hills (Girringun) National Park. The park is quite remote, located about 110km north of Townsville and 50km southwest of Ingham. It is one of the Wet Tropics World Heritage Areas and is a World Heritage Site. In the wet season, there is an abundance of rain, but outside of the wet season, the water supply can be very unreliable.

The Ranger Base Station and camping area at Princess Hills had been reliant on a dam for their water supply and water storage. The water was used for showers and cooking but was not potable. Outside of the wet season, the water supply had been running low and was proving inadequate.

Queensland Parks and Wildlife Services commissioned Think Water Mareeba to design a system that could switch their regular water supply from dam water to bore water and that would include a solar-powered bore pump and the option for a backup generator. While supply from the dam would be switched, the dam would remain as a backup water source.

There were four main stages to the project:

  1. Remote design of a bore pumping solution
  2. Preparation of the site by rangers
  3. Product ordering and logistic planning
  4. Installation of the bore pump and solar panels.

The 90m bore already existed in the national park but were not in use. Due to the remoteness of the park, a site inspection was not practical. Rangers provided photos, measurements and a drill log. Think Water used the bore log from when the bore had been first drilled to “size” the bore – determining the depth, standing water level and yield of the bore.

Array Frame Installation at Princess Hills  National Park
Array frame installation at Princess Hills National Park

Think Water designed a solution that allowed water to be pumped from the bore using a Franklin Bore Pumping System. The water would be pumped uphill a distance of 1km to existing poly tanks. In selecting the appropriate bore pumping system, friction loss and elevation gain needed to be calculated. Part of the solution included the inclusion of an eight-panel solar powered bore pump.

Once the bore pump and solar panel design was locked in, the rangers prepared a cement pad for the solar panels and dug holes for the poles which would hold the solar panels up.

Product ordering was vital in this project due to its remoteness. The team at Think Water ordered a complete bore pumping system from Franklin which included the pump, motor and pole mounting kit. Electric cable to connect the bore pump and stainless steel wire to support it were sourced from preferred suppliers. A bore cap manifold and automatic pressure switch were ordered as well as a float level. As the system would have the option to connect to a generator, a powerpoint and Franklin Controller needed to be ordered as well. Every little piece of equipment (as well as backups) was prepared in readiness.

In mid-June 2021, during the dry season, work started on the project. The actual installation took two days onsite. As the rangers had already prepared the cement pad and poles for the solar panel, the solar panel array was able to be installed quite quickly. All the preparations for the bore pump were done on the surface. A solar electrician connected the bore pump with the solar panels and Franklin Controller, including a solar sub drive system.

In the spirit of true bush innovation, a 4WD attached to a cable, which then ran over a wheel, lowered the bore pump into the bore until the pump was submerged, suspended by the poly pipe and stainless steel cable. The actual opening of the bore is only about five inches wide. The bore pump itself is about one metre long and quite narrow so it can fit into the bore opening. While innovative, the installation was actually quite precise. The installation stage included the installation of a float level attached to a pressure switch that tells the pump when to turn off. The bore pump itself was wrapped in a PVC shroud to help keep the motor cool. The bore cap manifold was installed and the whole solar-powered bore pumping system was thoroughly tested before handover.

An interesting aspect of this project was the inclusion of a solar sub drive which provided “run dry” protection for the bore pump and was a vital safeguard. This required a variable speed pump to adjust for speed changes associated with varying solar power supply.

While the remoteness of this project was very challenging and required excellent planning and logistics, the results were worth it. The solar-powered bore pump provided a very low maintenance solution – with only occasional cleaning of the solar panels required. Queensland Parks and Wildlife were very happy with the outcome and have since enlisted Think Water to help with other projects.