Concentrated solar optics (e.g., Fresnel lenses) focus sunlight onto a receiver, converting it into high-temperature heat. That heat is stored in a thermal (heat) battery. Because energy is stored thermally, it avoids many of the degradation issues and material constraints of chemical batteries. When power is needed, the stored heat drives a heat engine (or equivalent conversion) to produce electricity on demand.

They claim electricity production at $0.04 per kWh, which is in the range of existing solar & wind electricity production.

They’re a start-up and tying their fortunes to the data center boom. Why pick this instead of existing solar+batteries, though? They say it has advantages over existing solar. It needs simpler materials and doesn’t rely on Chinese supply chains.

Exowatt’s ‘next-generation renewable energy’ tech could power data centers faster: - The Miami-based company raised $70 million to commercialize its solar-powered energy system, which can provide round-the-clock power without a grid connection.