Fourth Power’s Sci-fi Thermal Batteries Could Be Cheaper Than Pricey Natural Gas Power Plants

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

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

The four-year-old, Cambridge, Massachusetts, startup has been refining nan exertion for nan past 2 years, and it’s now preparing to build its first 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 costs that could undercut some lithium-ion batteries and peaking natural-gas plants.

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

In normal operation, Fourth Power envisions charging and discharging daily, providing continuous energy for astir 8 hours aliases 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 only 1% of stored power per day.

The institution is presently moving extended testing connected smaller versions of nan system. “We’re now moving cycles to make judge that we’re getting nan expected magnitude of powerfulness retired and to guarantee nan strategy is durable,” Ganesan said. 

Alongside those tests, nan institution is designing a 1-megawatt-hour objection battery. To build that project, Fourth Power has raised $20 cardinal successful a information it’s calling a Series A Plus, nan institution exclusively told TechCrunch. The information was led by Munich Re Ventures pinch 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, nan costs of storing energy utilizing its thermal batteries will autumn to $25 per kilowatt-hour, one-tenth nan costs of lithium-ion batteries. 

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