Princeton Alumna Founder Rachel Stein Launches Clean Energy Venture in Trenton

Rachel Stein, a Princeton University alumna, launched a new clean energy venture this fall called Fieldstone Energy, building grid-scale battery storage systems designed specifically for small municipal utilities that have historically been priced out of larger battery storage vendors' offerings.

Stein spent several years working as an energy policy researcher before deciding the biggest barrier to renewable energy adoption for small utilities wasn't political will but simply a lack of financing and technical products scaled to their size. Fieldstone's storage systems are modular, allowing smaller utilities to install battery capacity in phases rather than committing to the large upfront capital investment required by systems designed for major utility providers.

"Every battery storage vendor I researched was building for utilities with millions of customers," Stein said. "Meanwhile, dozens of small municipal utilities across New Jersey wanted to add storage capacity but couldn't get anyone to return their calls because the deal size was too small to bother with. That gap was the whole business idea."

Fieldstone operates out of a converted manufacturing facility in Trenton and has signed contracts with four small New Jersey municipal utilities so far, with two additional deals under negotiation. The company has raised $9 million in early-stage funding, including participation from a state clean energy investment fund.

Stein says Fieldstone's modular approach has drawn interest from municipal utilities in neighboring states as well, though the company's initial focus remains on building out its New Jersey customer base first.