Fourth Power’s sci-fi thermal batteries could be cheaper than pricey natural gas power plants

Fourth Power’s instrumentality connected long-duration vigor retention sounds similar thing retired of a James Bond film. The thermal batteries travel implicit with superheated liquid tin and argon-filled hermetically sealed chambers. The company’s goal, though, is acold much prosaic — to store energy inexpensive capable to marque solar and upwind an evident prime for 24/7 power.

Here’s however the exertion works: To store energy, energy from the grid heats blocks of c wrong insulated chambers filled with argon gas. When powerfulness is needed, the strategy pumps molten tin heated to a scorching 2,400°C (4,352°F) done graphite pipes — the lone cost-effective worldly that tin withstand those temperatures. Special star panel-like devices called thermophotovoltaic cells past person the vigor backmost into energy by capturing the white-hot tin’s infrared light.

The four-year-old, Cambridge, Massachusetts, startup has been refining the exertion for the past 2 years, and it’s present preparing to physique its archetypal full-scale battery, molten tin and all. If each goes to plan, Fourth Power plans to present commercial-scale batteries to customers successful 2028 astatine a outgo that could undercut some lithium-ion batteries and peaking natural-gas plants.

“Our projections are for the first-of-a-kind — the archetypal ones to marketplace — that they’ll beryllium outgo competitive,” Arvin Ganesan, Fourth Power’s co-founder and CEO, told TechCrunch. “Our comps for these markets are precise high.”

In mean operation, Fourth Power envisions charging and discharging daily, providing continuous energy for astir 8 hours oregon more. That’s doubly arsenic agelong arsenic astir grid-scale lithium-ion batteries are designed for. The insulation system, made from petroleum coke (a discarded merchandise from lipid refining), keeps temperatures remarkably stable, losing lone 1% of stored vigor per day.

The institution is presently moving extended investigating connected smaller versions of the system. “We’re present moving cycles to marque definite that we’re getting the expected magnitude of powerfulness retired and to guarantee the strategy is durable,” Ganesan said. 

Alongside those tests, the institution is designing a 1-megawatt-hour objection battery. To physique that project, Fourth Power has raised $20 cardinal successful a circular it’s calling a Series A Plus, the institution exclusively told TechCrunch. The circular was led by Munich Re Ventures with information from Breakthrough Energy Ventures and DCVC. The startup antecedently raised a $19 cardinal Series A successful 2023.

Ultimately, Fourth Power hopes that erstwhile it hits large-scale production, the outgo of storing energy utilizing its thermal batteries volition autumn to $25 per kilowatt-hour, one-tenth the outgo of lithium-ion batteries. 

“There’s not a batch of moving pieces. There’s not a batch of players successful the proviso chain, which means that you tin get to outgo targets successful a reasonably straightforward way,” Ganesan said. “We consciousness the $25 people is reasonably straightforward to achieve.”