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Primus Power
Primus Power is a producer of low-cost, grid-scale electrical energy storage solutions
About Primus Power
Primus Power, established in 2009, operates in the grid-scale electrical energy storage sector. The company was co-founded by Tom Stepien, who also served as its CEO. Stepien brought over three decades of experience in engineering, operations, and general management from both small and large companies, including a significant tenure as a VP/GM at Applied Materials, where he managed a $500 million business. His background includes a BS and MS in Mechanical Engineering from MIT. The founding team also included Rick Winter and Dr. G.J. la O', who served as a technical advisor with extensive experience in battery design and a PhD in Material Science from MIT.
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The company focuses on providing long-duration, fade-free energy storage solutions designed for the smart grid. Its primary business involves manufacturing and selling zinc-bromide flow batteries. These batteries are targeted at commercial and industrial clients, data centers, microgrids, and utilities, both in the U.S. and internationally. Primus Power's business model is based on the sale of its modular energy storage systems, with revenue generated per system sold. The company's mission is to support the global transition to 100% renewable energy.
Primus Power's core product is the EnergyPod, a scalable zinc-bromide flow battery system. The second generation, EnergyPod 2, is a modular unit with a 25 kW power rating and 125 kWh of energy capacity, providing a five-hour discharge duration. A key feature is its projected 20-year lifespan with no capacity fade, a significant advantage over other battery technologies. The system's design is unique due to its single-tank, membrane-less architecture, which reduces maintenance costs associated with membrane degradation common in other flow batteries. These systems are scalable from 25kW to over 25MW, serving various applications such as peak shaving, renewable energy integration, frequency regulation, and providing backup power.
Throughout its history, Primus Power secured significant funding from a mix of venture capital, strategic investors, and government grants. The company raised approximately $92 million in equity over eight rounds, with its Series D round in 2017 raising $32 million. Investors included I2BF Global Ventures, Anglo American Platinum, DBL Partners, Matador Capital Partners, and Success Dragon. Additionally, it received over $20 million in grants from entities like the U.S. Department of Energy (DOE), the Advanced Research Projects Agency-Energy (ARPA-E), and the California Energy Commission (CEC). These funds supported the development and deployment of its technology, including a notable project to install a 25 MW/75 MWh EnergyFarm in the Modesto Irrigation District. Keywords: energy storage, flow battery, grid-scale storage, zinc-bromide battery, smart grid technology, renewable energy integration, long-duration storage, Primus Power, Tom Stepien, EnergyPod, peak shaving, microgrids, utility-scale battery, electricity storage, cleantech, energy infrastructure, stationary storage, power grid stability, battery technology, fade-free battery
At a glance
- Status
- Operational
- Founded
- 2009
- Headquarters
- Hayward, United States
- Employees
- 17
- Open positions
- None listed
- Dealroom signal
- 75.2/100
- Sub-industry
- Energy Efficiency, Energy Storage
- Sector
- Energy, Battery, Sustainable Development Goals, Climate Tech, Stationary Energy Storage, Alternative Battery Chemistry, Grid Technology, Hard Tech, Long Duration Energy Storage
- Technology
- Hardware, Deep Tech
- Business model
- Manufacturing
- Client focus
- b2b
Knowledge graph
More headlines
Funding history
Company financing events and reported valuations.
| Deal type | Date | Amount | Valuation | Investors | Source |
|---|---|---|---|---|---|
| GRANTOther financing | Jun 2019 | $4M | — | Undisclosed | — |
| FundingOther financing | Dec 2018 | $0 | — | BIRD Foundation | — |
Growth signals
Latest recorded traffic for Primus Power is 670 monthly website visits, down 60.6% over the last three months. Primus Power's team declined 5.6% over the past year.
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Investments and acquisitions
Recent portfolio relationships for companies that also act as investors or acquirers.
Investors
From Dealroom's funding and investor records, grouped by the round each investor first entered.
Seed4 investors entered at this stage
US Department of Energy- BABonneville Power Administration
ARPA-E
California Energy Commission
Series A1 investor entered at this stage
Series B and later5 investors entered at this stage
Chrysalix Venture Capital
I2BF Global Ventures
DBL Partners
Anglo American- MPMatador Capital Partners
Other known investors1 additional known investor
BIRD Foundation
Source: Dealroom Talent Intelligence.
Global footprint
team presence
Market sentiment
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Source: X recent search ranked by engagement (likes + retweets) · Synthesis by Claude · Cached for 1 hour
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