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Aug 7, 2013

A High-Renewables Tomorrow Today: King Island, Tasmania

 

Halfway between the island state of Tasmania and mainland Australia, in the heart of the Bass Strait, is rugged, windswept King Island. With a population of just under 2,000 and an area of just over 400 square miles, tiny King Island is becoming a big leader in electricity generation, demonstrating that a high-renewables future is possible.

King Island, and especially greater Tasmania, face many challenges due to climate change including water availability, flooding of coastal settlements, a rise of bushfires, and decreased agriculture and aquaculture industries. Although Australia’s contribution to global greenhouse gas emissions is small—and Tasmania’s even smaller, thanks in part to large amounts of hydro—the island has a goal of reducing carbon emissions by 60 percent from 1990 levels by 2050.

Tasmania is on track to meet that target, thanks in part to lessons learned and the success at King Island. King is providing a significant demonstration of the potential opportunities for Tasmania through its King Island Renewable Energy Integration Project (KIREIP). Initiated by the government-owned electricity provider, Hydro Tasmania, KIREIP’s goal is to not only reduce dependence on fossil fuels, but also to help constrain power prices on the island.

Many islands use diesel to produce electricity. Although inefficient and expensive, it’s more accessible than other forms of fossil fuels for remote locales. Before any renewable energy technologies came to the island, King Island residents were consuming 4.5 million liters of diesel each year. By 2011, mainly through the use of wind turbines, that number was down to 2.6 million liters. KIREIP is hoping to reduce that number to 1.6 million liters, meaning that 65 percent of the annual electricity used on King Island will come from renewables, with shorter durations of 100-percent-renewables power. KIREIP, supported by both Tasmanian and Australian government funding, will use a mix of solar, wind, biodiesel, storage and smart grid technologies to accomplish this goal.

Wind Power and the Roaring Forties

In the 1600s sailors took advantage of the raging winds in the Southern Hemisphere between the latitudes of 40 and 50 degrees south to make record trade runs. Nicknamed the Roaring Forties, these winds blow directly across Tasmania and are bringing power to thousands of homes on the island through wind farms built on the coast of Tasmania. In 1998 Hydro Tasmania installed three 250-kilowatt wind turbines at Huxley Hill on King Island. In 2000 Hydro Tasmania added more wind turbines, bringing the rated capacity of the wind farm to 2.45 megawatts, with the aim of further reducing cost of electricity supply through savings in diesel fuel use.

Hydro Tasmania’s latest wind project, TasWind, hopes to install 200 more wind turbines on King Island.The proposed $2-billion wind farm will generate an estimated 2,400 gigawatt-hours of electricity per year, enough to power nearly a quarter of a million households. Unlike the Huxley Hill wind farm, which feeds into King Island’s grid, the TasWind project would export electricity to Victoria on mainland Australia.

Despite its potential benefits, TasWind has not been all smooth sailing. Strong opposition has come from some residents who believe the island’s potential as a global tourism destination will be destroyed and think the project should be scrapped for a luxury golf course. Proponents claim the wind farm would create around 500 direct and indirect jobs and millions of dollars of additional economic benefit for the island. Even in light of vocal opposition, 59 percent of King Island voters recently approved TasWind to go ahead with a feasibility study for the project. TasWind estimates the economic returns to King Island to be between $225 and $310 million over the life of the project.

Solar

Hydro Tasmania has also installed six dual-axis tracking PV arrays on King Island, providing 100 kilowatts of solar power—200 megawatt-hours per year—to King Island’s power station. The solar array diversifies the renewable power sources so that when the wind isn’t blowing, King Island can still be generating energy from a renewable source. It also serves as a demonstration of how a variety of renewable energy technologies operate in an integrated system.

Renewables Firming

One of the most exciting projects in KIREIP is the installation of two diesel-powered rotary uninterruptible power supply (D-UPS) generators. When there is enough wind energy to meet the entire customer demand, the D-UPS switches off all diesel generators. Each D-UPS unit has a large mass flywheel, which uses excess wind energy rather than diesel power to maintain its motion. Without the D-UPS, if the wind generation were to reduce quickly the diesel generators would not be able to switch back on fast enough—resulting in a gap in power generation and a blackout.

The D-UPS—the first time ever being used in an island grid of this size—will allow for periods of 100-percent-renewable-energy penetration on King Island, which it achieved for the first time last month. “Although there are remote area power systems in some parts of the world that are capable of supplying the energy needs of single homes or small villages, this is the first remote system on this scale capable of supplying the power needs of an entire community, including industrial customers and an extensive distribution network, solely through wind and solar energy,” Simon Gamble, KIREIP project director, said in a press release. “Having established that zero diesel operation is possible, we are now looking to increase the duration for which we can operate in this mode.”

Energy Storage

To extend those periods of 100-percent-renewable-energy penetration, and because there is often more wind power than can be used, Hydro Tasmania is installing energy storage. Its 3 megawatt/1.6 megawatt-hour UltraBattery storage system, the largest battery ever installed in Australia, will have the capacity to power the entire island for up to 45 minutes. Storing wind energy when there is excess generation and making it available when it is needed to meet demand will help maintain the stability of the power grid.

Smart Grid

Another part of KIREIP currently in progress is the Smart Grid Project. The smart grid will match the level of energy demand with renewable generation. Hydro Tasmania is currently enlisting volunteer households to have smart grid technology in their homes connected to their electric hot water system. When the wind slows down, instead of increasing diesel generation, the smart grid will turn off hot water services for a couple of seconds, until the wind picks up again. While the temperature of the hot water won’t drop, the impact of not needing to start up the diesel generators will make a huge difference. This pilot program will last for up to three years with the hope of expanding it over the entire island.

Switching to Biodiesel

Hydro Tasmania is currently testing different biodiesel mixes at the King Island power station, in order to substitute biodiesel for the diesel currently used. It tested a 20-percent-biodiesel blend, and is presently testing a 100-percent-biodiesel blend made from recycled cooking oil and tallow. By substituting biodiesel, in conjunction with the renewable energy and smart grid technologies, the project hopes to cut carbon dioxide emissions by 95 percent.

Solutions developed under KIREIP have the potential to be replicated across Tasmania, and from there across mainland Australia, and even beyond. As Hydro Tasmania Chairman David Crean said in a statement, “The way these technologies are being used and integrated is world-leading and another example of the clever solutions to real-world problems that have been developed in Tasmania and can be exported globally.”

Image 1 courtesy of via Kurt Barnfather/Wikimedia Commons. Image 2 courtesy of Shutterstock.

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