Flatiron Energy has advanced three to five companies to submit definitive bids for the platform in mid-September, said sources familiar with the situation.

The equity valuation range is being talked in the USD 400m – USD 600m range, but final bids may well exceed that given the competitive nature of the auction.

Fellow New England battery builder Plus Power and energy IPP Invenergy have taken looks at the platform, while funds such as TPG Rise, Copenhagen Infrastructure Partners and Manulife have also taken a look.

The platform carries risk as it hasn’t commercialized a project yet and is advancing projects in nascent markets, but the process is being driven by demand for battery energy storage and experienced development teams.

Flatiron secured a strategic investment from Hull Street Energy in July 2024, while securing a follow-on commitment from Hull Street in October 2025 and also upsizing its existing credit facility to USD 250m with HPS Investment Partners.

NPM reported on March 25 that Flatiron was looking to raise additional capital, then reported on April 27 that Guggenheim Securities had been retained.

A sales process then launched earlier this spring.

Plus Power and TPG declined to comment. Flatiron, Hull St., and the rest of the prospective bidders did not return calls for comment.

Project pipeline

Overall, Flatiron has 2 GWh in construction and ready-to-build and 4 GWh of contracted backlog. Specifically, the platform expects to have 1.8 GWh placed-in-service by the end of 2027 and an additional 1.8 GWh of contracted backlog.

One of its first big projects, the 200 MW / 800 MWh Taft storage project in Worcester County, Massachusetts, is expected to commercialize later this year.

More recently Eversource Energy, National Grid and Unitil sought approval last month from Massachusetts Department of Public Utilities (DPU) on a power purchase agreement with Flatiron on two of its projects: 250 MW Energizar BESS in Suffolk County of which the utilities would offtake 80% of the power and Salt Cod BESS in Bristol County, of which it would offtake 100% of the power.

The DPU submitted a second set of requests on those projects on August 11 to the Massachusetts Department of Energy Resources (DOER) who selected the Flatiron projects and the 700 MW Trimount BESS project being developed by Jupiter Power in it first round of solicitation.

It also submitted projects in NYSERDA’s inaugural Index Storage Credit solicitation as well as the Maryland Public Service Commission’s Round 1 of its Next Generation Energy Storage Capacity Credits solicitation.