RMI Outlet has a look at the path towards 100% renewables being trodden by Tasmania's King Island - A High-Renewables Tomorrow Today: King Island, Tasmania.

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. ...

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.”

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.

The Australian has an article on efforts to power Tasmania entirely with renewable energy - Green dream within reach.

According to a report for the Council of Australian Governments, while most states will suffer a loss to gross domestic product as a result of the 20 per cent mandatory renewable energy target and carbon pollution reduction scheme, they will add $580million to Tasmania's GDP by 2030.

Sydney-based geothermal power company KUTh Energy Ltd is one of many that sees Tasmania has a key to a global revolution in green energy. "We think this is a realistic play: to make Tasmania a completely green state, a totally renewable state, a showcase of renewables: wind, wave and geothermal," KUTh managing director David McDonald says. "It's a little bit like (California's) Silicon Valley creating the first microchip and becoming the centre of computer software. Tasmania will become a technology hub."

Geothermal exploration licences cover half the state. KUTh recently identified a hot rocks resource in the state's midlands independently assessed at 260,000 petajoules (a measure of heat stored at depth). "If you can extract just over 1 per cent of that, then that would have the capacity to generate about 300 megawatts of power for a 30-year period," McDonald says. "That 300mW of power is about 25 per cent of Tasmania's total power usage." He says 5 per cent to 6 per cent could be extracted, enough to power the entire state and export energy to mainland states via Basslink.

Hot rock energy generation involves pumping water at high pressure deep into the ground where it is heated to 180C by naturally hot granite rocks. It returns to the surface as steam, which turns turbines that generate the power. The water is returned to the ground in a closed-loop system that involves little water loss but that can provide a reliable, uninterrupted power supply. KUTh plans to develop an initial 1.5mW plant, scaling up to an $80m to $90m, 20 to 50mW plant.

In terms of wind, Roaring 40s is building a new 138mW wind farm at Musselroe, in the state's northeast, which it says will be able to meet the needs of 55,000 homes and reduce greenhouse gas emissions by 300,000 tonnes a year. Roaring 40s, a joint venture between Hydro Tasmania and the China Light and Power Group, already has a 140mW wind farm at the state's northwest tip, at Woolnorth.

A 225mW wind farm is planned for the central highlands by US-based National Power. And local company Eco Energy Solutions plans a wind turbine assembly plant at Devonport as a forerunner to a $23m manufacturing plant. Employing 386 people, it would make a range of turbines for local use and export throughout Australasia, southeast Asia and the Pacific.

Offshore, a trial of wave and tidal power generation is being conducted by Sydney-based BioPower Systems near Flinders and King Islands in Bass Strait. The company has designed unique ocean equivalents of wind turbines, devices 20m to 25m long secured to the ocean floor that harness the power of waves and tide. ...

BioPower chief executive Tim Finnigan says analysis suggests Tasmania has the potential to generate 500mW through tide and wave, to be exported interstate. "Tasmania is perfect: on the west coast you've got world-class waves, among the best in the world, and through the Banks Strait and Flinders Island network you have very strong tidal flow," Finnigan says. "Tasmania has a great outlook on uptake of renewables."

While the trials - both 250 kilowatts - are under way, the company will prepare the groundwork and approval permits to build large-scale commercial generation wave and tide power farms of up to 50 1mW turbines. "It's a staged process building to 30mW to 50mW - when we get to that scale the economics start to compete directly with wind," he said.

Hydro Tasmania is also exporting its expertise to the world, including a recent $1.3m project to conduct feasibility studies for four projects in Sarawak.