Cutting the cable: Kangaroo Island eyes switch to 100% renewable energy

Kangaroo Island is one of the great icons of Australian tourism. As Andrew Boardman, the chief executive of the Kangaroo Island council, says: “You can’t buy a name like that.”

But now the third-biggest island in Australia, which lies just 120kms from Adelaide, wants to make its mark in a different way: by supplying 100% of its electricity needs and much of its transport fuels through locally sourced renewable energy.

The island is calling for proposals that could use a mixture of its local resources – solar power, wind energy, biomass and even ocean energy – and combine those with battery storage, smart software and the existing diesel back-up. Even more dramatically, it is also supporting a push to cut the island from the mainland grid.

Indeed, the move has been prompted by a need to update and replace the ageing cable that currently supplies electricity from the mainland.

South Australian Power Networks has called for “alternative proposals”. If someone can come up with a proposal that matches the $45m to $50m replacement cost of the cable, then they will consider it. They aim to make a decision by the end of the year.

Boardman says: “100% renewable is a very real, very clear target ... Technology is not the issue. We have got solar, wind, wave, tidal, biomass. There is nothing we can’t really do.”

If the idea works, Boardman says, it could make the island – with a population of 4,600 and 200,000 visitors each year – the first in Australia to be entirely reliant on its own renewable resources for electricity and transport. It could provide a blueprint for others to follow.

Other islands, such as King Island and Lord Howe Island, have or are about to install significant renewable and battery storage arrays but still rely on fossil fuels for 20% to 30% of their electricity needs.

“We could create a centre of excellence,” Boardman says. “If we can make it work on Kangaroo Island, it is transferable for other areas.”

Boardman says the island has received a “phenomenal response” to the call-out for alternatives and the council has teamed up with the Institute of Sustainable Futures in Sydney to help find the best alternative.

ISF director Chris Dunstan says the institute got involved because he saw the Kangaroo Island tender as an opportunity too important to miss.

“It’s not just about deferring spending on networks for a year or two, it’s about a whole new energy paradigm,” Dunstan says.

He and Boardman are hoping that South Australian Power Networks allows more time for alternative proposals to be put together, which is why the ISF has stepped in to push the idea that there are good alternatives to simply laying a new cable.

Earlier this year, ISF put together a tentative plan that proposes 8MW of wind turbines, 4MW of centralised solar photovoltaics (PV) and 4MW of rooftop PV, with about 3MW battery storage, most of it co-located with solar PV.

This would be combined with energy efficiency measures and continuing the small diesel plant, which would account for just 3% of the load. Dunstan estimates the set-up could cut bills on the island by 30% but his team is also looking at other ideas.

Boardman wants to go one step further and use 18,000 hectares of blue gum plantations – the legacy of investment by the since-failed plantation company Great Southern Plantations – as feedstock for a renewable biofuel.

That could be used to replace the six million litres of diesel it imports at high cost from the mainland each year, as well as providing electricity and waste heat, and the power needed to desalinate water.

There is little else to do with the plantations, he says, as there is no port to export the wood back to the mainland.

And he is keen to play on the island’s reputation as an eco-tourism destination. The council already has three Nissan Leaf electric vehicles for hire and six re-charging stations through the island.

The island is encouraging more electric vehicles and Boardman talks of creating the world’s first renewable energy-powered “electric vehicle tourism highway”, linking the island with Adelaide via the Fleurieu Peninsula. The island already has 50kW of rooftop solar installed on its airport and another 14kW on the council chambers.

Boardman says there is no doubt that the technology is there but he has concerns about other issues such as who runs an island-only grid and who do they answer to? And, in 25 to 30 years’ time, when some of the technology needs replacing, who will pay for that? Another potential factor may be the pairing of fibre optic cable with a new electricity cable. Digital isolation is also a major consideration.

Whether the cable is cut or not, Boardman says that the island will need to upgrade its local network anyway. It features a series of “thin wires” or single-wire earth return lines built in the 1960s that no longer have the capacity to meet future demand. He envisages a series of linked micro-grids that can exploit local resources and increase reliability.

And, if the cable is not cut, Boardman sees opportunities for using that cable to export power from the island back to the mainland, taking advantage of its local energy resources, including the eucalypt plantation.

“If we can show that renewable energy is technically and economically viable for Kangaroo Island, it would be a powerful precedent for communities around Australia who are seeking to develop their own renewable energy.”

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