‘World’s first working thermal battery’ promises cheaper energy storage

Various battery proposals sound promising, but few seem to survive the development stage and make it commercially. This outfit says it already has some sales, and plans to ‘build 100-megawatt-plus installations within a couple of years.’ Will it work out that way?

A South Australia-based startup says it’s built a thermal energy storage device with a lifetime of at least 20 years that can store six times more energy than lithium-ion batteries per volume, for 60-80 percent of the price, reports New Atlas.

South Australia has recently put the world’s biggest lithium battery into operation – but perhaps it should’ve waited.

Climate Change Technologies, also known as CCT Energy Storage, has launched its TED (Thermal Energy Device) with a set of remarkable claims.

TED is a modular energy storage unit that accepts any kind of electricity – solar, wind, fossil fuel-generated or straight off the grid – and uses it to heat up and melt silicon in a heavily insulated chamber. Whenever that energy is required, it’s pulled out with a heat engine.

A standard TED box holds 1.2 megawatt-hours of energy, with all input and output electronics on board, and fits easily into a 20-ft (6-m) container.

Here are some of CCT’s banner claims about the TED: For a given size volume, it can store more than 12 times more energy than a lead-acid battery, and several times more than lithium-ion solutions. Installations can scale from 5-kilowatt applications out to a virtually unlimited size.

Hundreds of megawatts of instantly accessible, easily controllable power should be no problem – all you need to do is add more units, plug-and-play style. In the case of an outage, each TED device can remain active for about 48 hours.

It can also charge and discharge at the same time, and there are only three moving parts per box, so maintenance is almost negligible.

Where lithium-ion and other batteries degrade over time, perhaps dropping to 80 percent capacity in some 5,000 cycles or so, the TED system has shown no signs of degrading after 3,000 cycles of service on the test bench, and CCT’s CEO Serge Bondarenko tells us over the phone that the company expects its units to last at least 20 years.

“Molten silicon just doesn’t degrade like lithium does,” says Bondarenko.