A Busselton farmer has not had to pay for any of the energy they used for more than two and a half years after installing a renewable energy device.
Farmer Lucy Stuart helped pioneer a vanadium redox flow battery when she bought a battery for her native tree nursery she owns with her husband Ian.
Ms Stuart said since they had installed the vanadium flow battery, they had not experienced any interruptions to power and had not paid for any power.
The battery was the first vanadium redox flow battery installed in WA and was the first of its type sold by VSUN Energy which markets industrial-grade vanadium redox flow batteries.
A 10 kilowatt power, 100kWh energy CellCube unit built in Austria, was sent in a sea container to the Stuarts' rural nursery where native trees are cultivated from seedlings.
The Stuarts wanted a power supply to meet their increasing demand for electricity.
The CellCube stores energy from a 15kW solar photovoltaic system, enough to run for 10 hours at maximum output.
Ms Stuart said where they were located the grid only provided single-phase power, but they wanted three-phase power to use a workshop and heavier machinery.
"Anyone, really, can just plug it in and operate it, there is not much technical background required" she said.
A low risk of fire and peace of mind were other reasons why they chose a vanadium system over lithium, given the nursery's rural location.
"We cannot always be down at the farm, and our tree nursery does depend on uninterrupted power supply for the irrigation of the seedlings," she said.
The batteries can store energy from renewable sources, including solar, wind or wave power, and release it when required.
The technology relies on a vanadium electrolyte solution held in storage tanks.
Such batteries can be charged and discharged at the same time and can be cycled often and deeply, which differentiates them from lithium derived storage.