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

Fourth Power’s take on long-duration energy storage sounds like something out of a James Bond film. The thermal batteries come complete with superheated liquid tin and argon-filled hermetically sealed chambers. The company’s goal, though, is far more prosaic — to store electricity cheap enough to make solar and wind an obvious choice for 24/7 power.

Here’s how the technology works: To store energy, electricity from the grid heats blocks of carbon inside insulated chambers filled with argon gas. When power is needed, the system pumps molten…