New battery technologies offering cost and efficiency advantages are the flavour of the season with a new silicon storage device being the latest to join the race.

Developed by Adelaide company 1414 Degrees based on patented CSIRO research, the new silicon storage device costs a tenth as much as a lithium ion battery to store the same energy. A prototype molten silicon storage device is being tested at the company’s Tonsley Innovation Precinct site south of Adelaide.

Chairman Kevin Moriarty says there’s no comparison between the efficiencies of 1414 Degrees and Tesla’s lithium ion home storage battery. He explains that 1414 Degrees can store 500KWh of energy in a 70-centimetre cube of molten silicon, about 36 times as much energy as Tesla's 14KWh Powerwall 2 battery in about the same space. This also means that they can build a 10MWh storage device for about $700,000, compared to about $7 million needed by the 714 Tesla Powerwall 2 batteries to store the same amount of energy.

1414 Degrees has raised $500,000 of a $2 million seed capital issue that it hopes to complete by the end of next month. The company is discussing pilot trials with a hydroponic herb farm as well as wind farm suppliers. A $10 million public share issue is also being planned to fund construction of the first two 200MWh units.

The 1414 Degrees device stores electrical energy by using it to heat a block of pure silicon to melting point at 1414 degrees Celsius. It discharges through a heat-exchange device such as a Stirling engine or a turbine, which converts heat back to electrical energy, and recycles waste heat to lift efficiency.

A by-product of smelting metal quartz ores, the silicon material is abundant and cheap, and offers an attractive option as a storage medium because it is stable at the 1414-degree melting point, and can hold the heat for a week or two with adequate insulation.

Once proven at commercial scale, 1414 Degrees’ molten silicon storage device could become a revolutionary development in the evolution of cheaper and more efficient battery technologies for the storage of renewable energy. 1414 Degrees is just one among many players in the crowded field, and hopes to stand out with its plan to enter into joint ventures with customers or partners and share in the benefits. The 1414 Degrees device could, for instance, increase the revenue of a wind farm by 25 per cent, through increased output and by exploiting higher wholesale prices during low wind periods.

Image: 1414 Degrees chairman Kevin Moriarty and executive director and chief technical officer Matthew Johnson with a prototype of their silicon energy storage system (David Mariuz)