Sinergy Flow, a startup that develops solutions for long-duration energy storage, has closed a €7 million (~$8 million) late seed funding round.
CDP Venture Capital SGR led the funding round with the participation of 360 Capital, a European venture capital fund, and Tech4Planet, the National Technology Transfer Hub for Sustainability, established by CDP Venture Capital SGR through the Technology Transfer Fund, and Exergon, part of Audacia Group, a European venture capital fund.
BonelliErede served as the advisor to Sinergy Flow in the transaction.
The company claims to have developed proprietary technology using low-cost flow batteries for long-duration stationary storage, surpassing eight hours of continuous operation.
This enables the integration of renewable energy sources into electricity systems, while also valorizing sulfur-rich industrial byproducts and promoting a circular economy throughout the device’s lifecycle.
The funding is expected to speed up the development of its technology, complete commercial-scale validation activities, and prepare for market entry in utility-scale energy storage and standalone applications supporting electricity grids and renewable energy integration.
In partnership with A2A, an Italian multi-utility company, Sinergy Flow is executing a proof of concept as well as launching an industrial partnership aimed at validating the technology in real operational conditions and preparing for industrial-scale deployment.
“The work carried out by Sinergy Flow over these years, made possible in part from the strategic partnership with A2A, demonstrates how it is possible to bring such a disruptive technology closer to the industrial world. The results achieved so far confirm a tangible competitive advantage in the Long Duration Energy Storage segment. We continue to believe in the sector and in this technology’s ability to enable new solutions for the energy transition,” declares Lucrezia Lucotti, Partner at 360 Capital.
According to Mercom’s Annual and Q4 2025 Funding and M&A for Energy Storage report, VC funding in the Energy Storage sector in 2025 increased 30% YoY, to $4.8 billion across 75 deals, up from $3.7 billion across 84 deals in 2024.
In November 2025, Flux XII, a company developing advanced materials for aqueous flow batteries, raised $3.95 million in a seed funding round led by The Grantham Foundation.
