Diesel to ‘de-sal’ on Rottnest Island

Rottnest Island Water and Renewable Energy Nexus Project
Rottnest Island Water and Renewable Energy Nexus Project

Hydro Tasmania’s renewable energy innovation will help reduce the amount of diesel fuel needed to generate power and produce clean drinking water at one of Western Australia’s tourism jewels.

The Rottnest Island Water and Renewable Energy Nexus Project (WREN) will deliver both electricity and drinking water for Rottnest Island at lower cost, and with lower emissions, through innovative use of renewable energy and smart controls.

Hydro Tasmania’s hybrid off-grid solutions manager Simon Gamble said a novel aspect of the project is its focus on controlling the timing of an energy- intensive activity – running the island’s desalination plant – to make the best use of renewable energy when it is most abundant.

“Sophisticated smart controls will automate the desalination plant to operate at maximum capacity when wind and solar energy are most abundant, and store treated water for use at times of lower renewable energy availability. Running the plant on renewables rather than diesel will reduce the cost and emissions intensity of producing the island’s drinking water,” he said.

Until now, Rottnest Island’s current annual power consumption of 5GWh has been provided by five conventional diesel engines, two low-load diesel engines and a single 600kW wind turbine, installed in 2004.

Integrating Hydro Tasmania’s innovative control systems with the Rottnest Island desalination plant and water storage facility will allow the plant and pumps to be switched on when renewable generation outstrips demand on the island.

The Australian Renewable Energy Agency (ARENA) will provide up to $4.8 million in funding towards the $7.3 million project.

The project is part of an energy road map for Rottnest Island involving cost-effective options to reduce diesel consumption while still maintaining a reliable power supply that would meet the island’s current and future needs.

The WREN project will integrate education about power and water sustainability into the Rottnest Island visitor experience, by developing digital educational materials that will allow real-time interaction with the cutting-edge power/water system, and can be delivered via apps and within a new energy educational technology centre.

The project will also trial energy efficiency technologies to reduce overall power and water use on the island. Combined with smart demand-management of the desalination plant, it’s expected the advanced hybrid power system will achieve 45 per cent renewable energy penetration.

The WREN project holds exciting global potential, as similar power and water challenges confront many remote and island locations around the world.

“Rottnest Island offers an excellent demonstration site for an innovative technology that will have broad international application and offer global economic and environmental benefits,”
Mr Gamble said.

“Island communities in particular will watch its progress with interest, given the widespread current use of diesel to manage water treatment and desalination.”

The project will be completed by May 2017.