Flywheel mechanical battery with 32 kWh of storage in Australia


From pv magazine Australia

New South Wales-based startup Key Energy has installed a 8 kW/32 kWh three-phase flywheel mechanical energy storage system at a property in the Sawyers Valley, just east of Perth.

The installation involved a single flywheel, which stores energy mechanically meaning it has no fire risks, can run around 11,000 cycles without capacity degradation and boasts a 20-year to 30-year lifespan. While these systems have low energy density, they are substantially more durable than lithium-ion based chemical batteries.

This was a major drawcard for the owner of the Sawyers Valley property, who wanted a system that did not pose a fire risk, could power their three-phase loads and provide energy security as blackouts frequently affect the area.

The project marks Key Energy’s fourth installation, with another two expected to be commissioned this year. In total, the company has installed around 16 flywheel systems with over 300 kWh of capacity, including at a boarding school and at gas company APA Group’s commercial off-grid device stations.

Key Energy’s offgrid commercial installation

Key Energy says it aims to leverage this residential flywheel installation, as well as future projects, to qualify its technology for Western Australia's Stand Alone Power System (SAPS) program, run by state-owned utilities Western Power and Horizon Power. The program is part of the state’s broad strategy to replace its stringy regional network of poles and wires with renewable standalone alternatives, which usually include a solar array, battery and last-resort diesel generator. These systems have been found by the state to be far cheaper and significantly reduce carbon emissions.

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Flywheel battery systems are usually installed underground – a lengthy and costly process. Key Energy previously worked with the University of Technology, Sydney (UTS) to develop an above-ground enclosure for its storage systems. Key Energy says this has allowed it to shorten install times from one to two weeks with underground systems to just two days in the Sawyers Valley project.

Key Energy says it is also developing additional functionality for the flywheel, paving the way for virtual power plants (VPPs) which it believes could capitalise on the flywheel system’s robust cycling characteristics and long lifespan.

Key energy, founded in 2018, is based in the Sydney suburb of Chippendale and has a test site in nearby Alexandria. Since launching, it has attracted funding from the New South Wales government, City of Sydney and Energy Lab.

Key Energy’s flywheels are sourced from US-headquartered company Amber Kinetics, though the rest of the battery system is believed to be manufactured in Australia.


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