Startup spotlight: Photon Vault’s thermal energy storage

SkyTrough Parabolic Solar Collector (Credit: DOE)

Energy storage is a crucial component of the energy transition, but concerns about existing battery technology range from longevity to materials sourcing. One startup participating in DISTRIBUTECH aims to avoid both of those pitfalls with its thermal storage system.

A participating company in the DISTRIBUTECH International Initiate program, California-based Photon Vault will soon showcase its thermal energy storage solution at DISTRIBUTECH International, set for February 26-29, 2024 in Orlando, Florida.



The Photon Vault is a thermal energy storage design that stores energy as heat and releases it as electricity. The company says its technology is unique in that it is the only energy storage technology to combine medium-grade heat with electricity to achieve “best-in-industry” efficiency and economics.

Initially, Photon Vault will focus on harvesting heat energy from solar thermal power and industrial waste heat, but it says its systems can ingest heat from any source that is hot enough. Its solution includes both the process for generating the heat energy and its proprietary energy storage media in which the heat is banked.

“We have two core technology innovations,” said John Langhus, CEO, Photon Vault. “The first drives our economics and the second drives our scalability. Both are patented and do not use any toxic, rare, hazardous, or exotic materials. The Photon Vault is a grid-scale energy storage solution and is the first ever to be profitable for short durations of 4 hours, mid-range durations of 8-24 hours, and long durations of up to 100 hours or more.”

To discharge stored energy, Photon Vault turns its temperature gradient into a pressure gradient that turns a standard generator, which the company compares to running a refrigerator backwards – converting a temperature gradient into electricity, instead of the other way around.

The company says the custom-engineered composite material for its heat banks uses no exotic or rare minerals, and existing supply chains for the materials are dispersed and well-supplied. Photon Vault also says the material does not degrade from cycle to cycle, like batteries.

At DISTRIBUTECH, Photon Vault says it is interested in finding utilities that are interested in hosting pilot projects to demonstrate its technology at commercial scale.

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