Exowatt raises $50m to scale thermal-solar for AI datacenters

• Exowatt secured $50m to expand U.S. manufacturing of modular solar-thermal systems aimed at AI datacenters and heat-hungry industry.

AI datacenters have two problems: they use a lot of power, and they dump a lot of heat. U.S. startup Exowatt thinks solar-thermal can help on both counts — and it just raised $50 million to prove it at scale.

Unlike standard solar panels that make electricity, Exowatt’s collectors make heat, which can be stored cheaply and used when needed. That heat can drive absorption chillers to keep servers cool during late-afternoon peaks, or feed industrial processes that don’t actually need electrons, just reliable high-temperature energy. Pair that with conventional PV and smart controls and a campus can flatten its grid draw without building a giant (and expensive) wall of batteries.

The pitch to hyperscalers is straightforward: lower operating carbon, a hedge against price spikes, and better resilience when the grid is stressed. The company says the new funding will go into U.S. manufacturing lines, standardized “plug-and-play” skids, and field teams who can roll out repeatable blocks instead of bespoke science projects.

Of course, the unglamorous details will decide whether this flies. Roof loads, thermal fluids, safety systems, noise and plumes — all have to pass muster with local authorities and insurers. Reliability is everything for datacenters, so remote monitoring and fast-swap parts will be part of the package, along with a clear plan to recycle storage media and metals at end of life.

No one’s saying thermal-solar replaces batteries; it complements them. Use heat where heat makes sense, save the electrons for computing, and let batteries handle the split-second grid work. If Exowatt can deliver that in tidy, modular chunks, it could become a regular line item in the next wave of energy-hungry AI campuses.