The scientist said he had spent 20 years developing the metal hydrides that can bond with hydrogen.

The system uses power to create hydrogen, which is then stored until needed for electricity production via a fuel cell.

Professor Aguey-Zinsou said the alloy contained titanium and "other common materials", but declined to name them, pending the issuance of a formal patent expected within weeks.

The solid-state mix can operate in a range of temperatures – such as from minus-10 to 50 degrees – depending on the climate the storage was intended for.

"It's safe ... it's not flammable," he said. "You cannot create the conditions when you have a certain burst of hydrogen."

Hydrogen has lately emerged as a prospective alternative to fossil fuels. The Morrison government launched a National Hydrogen Strategy late last year, identifying break-even points needed to supplant gas and petrol.

UNSW"s Hydrogen Energy Research Centre, backed by $10 million from Providence Asset Group, reckons it is ready to produce the world's first hydrogen batteries for households as soon as early 2021.

"We aim to launch the LAVO [brand] commercial product by the end of this year, and start pilot production in the first quarter of next year," Alan Yu, a co-founder of Providence, said, adding the plan was to make the batteries in Australia.

"It’s cheaper and cleaner than buying from the grid," Mr Yu, an entrepreneur who also invests in artificial intelligence, said. "This will help households to accelerate the clean energy transition in Australia and save money."

Amy Kean, a board member of the hydrogen centre and director of Stride Renewables, said the household batteries would most likely hold up to 60 kilowatt-hours, or about five times the capacity of existing lithium storage on the market. About 130 centimetres high, the size of a small fridge, each would weigh 196 kilograms.

The cost could go as low as 2¢ per kW-hour, or less than one-tenth the cost of lithium rivals and buying power from the grid, making the storage highly competitive, Ms Kean said.

Bjorn Sturmberg, a research leader at the Australian National University's Research School of Electrical, Energy and Materials Engineering, said people "shouldn't underestimate the road from the science that works in the lab to mass deployment" in the market.

The conversion of electricity to hydrogen and back again would "multiply the inefficiencies", and he cautioned against expecting a rapid take-up of the product.

"The uses for hydrogen at the moment are extremely niche," Dr Sturmberg said. "This is a new opportunity within the niche."

Mr Yu said his company hoped to add hydrogen storage for the company's planned five-megawatt community-owned solar farm planned for Manilla, near Tamworth in northern NSW.

The batteries, held within two shipping containers, would aim to store about eight hours' worth of electricity, increasing the prospect that the nearby users could move off the grid entirely.

The aim is to develop dozens of such solar farms, backed up with wind and storage, in coming years, he said.