What is ESS?
ESS Tech, Inc. operates at the intersection of advanced materials science and grid-scale energy management. By designing and manufacturing long-duration energy storage systems, the company addresses the inherent intermittency of renewable energy sources such as wind and solar. Its iron flow battery architecture is engineered for high-cycle durability and safety, positioning the company as a key enabler for utilities and commercial operators seeking to enhance grid stability and energy resilience. Unlike traditional lithium-ion alternatives, the ESS platform offers a sustainable, non-toxic, and cost-effective alternative for long-duration storage, effectively bridging the gap between intermittent generation and consistent power demand.
How much funding has ESS raised?
ESS has raised a total of $88.3M across 10 funding rounds:
Unspecified
$493K
Series A
$3.2M
Series B
$13M
Series C
$30M
Debt
$350K
Private Equity
$23M
Unspecified
$17M
Debt
$900K
Unspecified (2013): $493K supported by NYSERDA
Series A (2015): $3.2M featuring Pangaea Ventures and Element 8
Series B (2017): $13M backed by InfraPartners Management, BASF, Panagea Ventures, and Cycle Capital
Series C (2019): $30M with participation from PTT Global Chemical, Softbank Group, Evergy Ventures, and Breakthrough Energy
Debt (2020): $350K led by PPP
Unspecified (2024): $17M supported by Queensland Government
Private Equity (2024): $23M, investors not publicly disclosed
Debt (2025): $900K, investors not publicly disclosed
Key Investors in ESS
Pangaea Ventures
Pangaea Ventures is a leading venture capital firm specializing in hard tech, focusing on investments in start-up companies that utilize advancements in materials, chemistry, and biology to tackle significant global challenges.
Element 8
E8 Angels is a non-profit membership community dedicated to accelerating the transition to a cleaner and more prosperous world through investments in emerging cleantech enterprises.
InfraPartners Management
InfraPartners Management LLP is an infrastructure investment advisor established in 2014, specializing in providing investment advice and management services in the infrastructure sector.
What's next for ESS?
With the infusion of $900K, ESS is well-positioned to scale its manufacturing capacity and expand its market footprint. The strategic focus will likely shift toward optimizing supply chain efficiencies and deepening partnerships with global utility providers to integrate its storage platforms into existing infrastructure. As the global demand for grid-level energy storage continues to surge, the company's ability to deliver reliable, long-duration solutions will be central to its long-term competitive advantage. Future growth will likely be characterized by increased commercial adoption and the continued refinement of its integrated energy management systems to meet the evolving requirements of a decarbonizing global economy.
See full ESS company page
