Australia’s Adelaide-based energy storage firm 1414 Degrees plans to deliver an 800MWh/50MW molten silicon thermal energy storage system (TESS) for deployment in energy grids by late 2018.
The molten silicon storage device can store 500kWh of energy in a 70cm cube, the firm said in the Australian Financial Review, and compared with Tesla’s recently launched 14kWh Powerwall 2 lithium-ion storage battery, the new technology stores 36 times more energy.
The firm has recently engaged engineers to prepare the TESS devices for commissioning and to develop a grid-scale energy storage system. They are currently evaluating 50MW turbines in collaboration with major manufacturers.
The technical team from 1414 Degrees will build the first 200MWh storage module, which chief executive Kevin Moriarty estimates will each cost around AUD $7 million (USD $5.2 million) to produce, during the next 12 months with additional funding from the upcoming Initial Public Offering, most likely in June.
As one of the companies bidding for a 100MW storage plant in South Australia, 1414 Degrees claims its molten silicon TESS could beat lithium-ion technology, with building a 10MWh plant for around AUD $700,000 (USD $528,000), or a tenth of the price of a Tesla battery-based project.
Moriarty said the silicon technology could spell the end of lithium-ion batteries. “There’s no comparison,” he told the Australian Financial Review. “Except for a few specialized circumstances, it will make them totally uneconomic, frankly.
“An advantage of our low-cost storage technology is that it does not reduce in capacity and require replacement as with batteries. The aim of the transition (from a carbon-dominated energy mix) should be to cut costs and pass as much benefit of free renewable sources onto consumers.
“This will not happen if the grid is locked into expensive storage in the long-term.”
However, Julia Attwood, an emerging-technologies analyst at Bloomberg New Energy Finance told Greentech Media that 1414 Degrees could only really claim superiority over lithium-ion in a combined heat and power generation (CHP) setting.
“The current electrical efficiency of 1414’s prototype is 31%,” Attwood said, “but they’re hoping to get to 40% or 50% for their commercial units. That’s a pretty low efficiency compared to lithium-ion batteries, which are over 80%.
“However, if you’re using the TESS not just to supply electricity but also heat, then the efficiency improves to over 80%, as you’re removing the turbine from part of the equation.”
A TESS unit providing district heat in combination with grid services could indeed be competitive with a battery, based on efficiency, she said.
Moriarty has confirmed that the device could achieve storage efficiencies of up to 90%, but only when used for CHP.
“The true gap in the storage market is in long-term energy storage,” Attwood said. “1414 is attempting to target this gap, but it’s missing the mark a bit, as its TESS can only store energy for a week, rather than the months that are really needed for seasonal storage.”
Lithium-ion batteries can technically store energy for months, he noted, but “it’s just very economically inefficient to use them that way,” Attwood added. Meanwhile, the long charging and discharging times of a TESS also mean it can’t participate in lucrative short-duration grid services.
“Overall, 1414’s silicon TESS system is an interesting technology and clearly an improvement over molten salt storage, but it will probably only be useful in a specific niche, with a wider system designed around it,” said Attwood.