Australia’s oldest wind turbines back in action with a Danish facelift, and a major life extension

This month, the last of the oldest turbines at Australia’s oldest continuously working wind farm, will be back in action, following a facelift and refurbishment that will deliver a major life extension.

The first turbines at the tiny – 2.45 megawatt (MW) – Huxley Hill wind farm on King Island were built in 1998, and its owners Hydro Tasmania had to decide whether to decommission the whole thing, like the Coddrington facility in Victoria, or go ahead with repowering, as is being contemplated at Woolworth in Tasmania.

A full decommissioning of Huxley Hill, as Pacific Blue is doing with the 18.2 MW Coddrington wind farm in Victoria, was never really considered because the set up at King Island is crucial to reducing its dependence on costly diesel, and wind has been a vital part of what has been a world-leading remote renewables-dominated micro-grid.

But a rebuild, or repowering, scenario that was initially top of the list in 2021, was ultimately thwarted by the devilish logistics of bringing massive turbines through King Island’s small ports from Tasmania.

“Initially we thought they would get to a point where we couldn’t maintain them and we’d need to replace them,” says Hydro Tasmania executive general manager of assets and infrastructure, Jesse Clark.

“But through the feasibility process we made contact with the supplier of refurbished units. We evaluated those against the economics and broader social impact of doing a full replacement and we got really excited by the idea of renewing these with refurbished units.”

The wind farm was built in 1998 with three 250 kilowatt (kW) Nordex N26 turbines, followed by two additional 850 kW Vestas V52 turbines in 2003, and a 3MW/1.5MWh lead-acid battery backup 15 years ago.

It also includes two 1 megavolt-amperes (MVA) flywheels, and a 1.5 MW dynamic resistor and a 1.5 MW solar farm that was commissioned in 2023.

The facelift – part of an $11.5 million refurbishment program that will also include a new battery – mostly focuses on the restoration of the nacelles, which houses all the generating components in a wind turbine, including the generator, gearbox and drive train.

The oldest and smallest turbines are being restored by Decowicon, a Danish company that specialises in refurbishing antique turbines, and the last of the three turbines is due to be returned to service within the next two weeks.

The younger turbines, currently in the hands of Vestas, will be back in action by the end of this year.  Their restored nacelles are waiting to be shipped home, a journey which will take until June-July, and the rebuild – with the help of massive cranes – will start in the Spring but only when they find a break in King Island’s savage winds. 

In the mean time, Hydro Tasmania is also working on refurbishing the foundations and towers to make sure they can hold up in the salt-blasted environment.

Mission to get King Island off diesel

The King Island Renewable Integration Project is regarded as a world-leading hybrid power system with what was at the time world-leading integration technologies and processes that have now been widely adopted.

It delivers around 65 per cent renewables – slashing the dependence on costly diesel fuel – and is capable of running on renewables only, as it achieved for nearly 1000 hours last year. However, in recent times, the share of diesel has increased to around 60 per cent because of the work on the wind turbines.

Once the turbines are back in action Hydro Tasmania will also begin the search for a new battery, one with a capacity of up to 4MW and with a duration of about an hour, Clark says.

The two Vestas turbines, when operational, supply 32 per cent of the island’s energy demand and replace 640,000 litres of diesel a year. The refresh – including the battery – should be wrapped up by 2027 and give the wind farm another 15-plus years of life, and return to delivering the anticipated diesel savings of 1.6 – 1.8 million litres per year.

Clark says the project will prove that old wind farms can be refurbished and it can be done with as little waste as possible. “The repowering will provide an important example of how to effectively maintain and refurbish aging wind farms to reduce waste and cost,” Clark says. 

Who was first? 

Being at the forefront of the repowering/decommissioning wave means a number of wind farm owners are claiming the “oldest” tag. 

Pacific Blue says Coddrington is the oldest still operating “commercial” wind farm, which was commissioned in July 2001, just pipping Western Australia’s Albany 34.5MW Albany wind farm by three months. 

Hydro Tasmania says Huxley Hill is Australia’s oldest “continuously working” wind farm.

But neither were first.

The country’s first commercial wind farm was Salmon Beach near Esperanza in Western Australia, which operated for 15 years from 1987.

The second were the Esperance wind farms on the state’s south coast which include the nine-turbine Ten Mile Lagoon project, commissioned all the way back in 1993, and the six turbines added at Nine Mile Beach in 2004.