ESS Tech Signs Letter of Intent With Juniper Energy for 500 MWh of Sodium-Ion Battery Storage Through 2032
ESS Tech and Juniper Energy signed a non-binding LOI to deploy 500+ MWh of sodium-ion storage, starting with an 80 MWh California project targeted for 2027.
Editor's Note ·
- Clarification:
- This article's 'What We Don't Know' section did not mention reporting, from one of the article's own cited sources (Energy-Storage.News), that raises questions about Juniper Energy's public profile: the outlet described Juniper's website as 'a single page with limited company information, built on Wix,' found the phone number listed on that website to be disconnected, noted that founder/Managing Partner Keith McDaniels is the company's only employee listed on LinkedIn with a background as a bankruptcy-and-restructuring attorney rather than in energy, and reported it received no response from Juniper to an email request for comment. Energy-Storage.News also noted Juniper announced a similarly sized 500 MWh sodium-ion 'strategic partnership' with a different company, Alsym Energy, in May 2026, and that it is unclear whether the two announcements relate to the same underlying deal framework. None of this changes the confirmed facts that ESS Tech and Juniper Energy signed a non-binding letter of intent and that the quotes and figures in this article are accurately reported, but readers assessing how substantive this announced partnership is should have this context.
Overview
ESS Tech, Inc. (NYSE: GWH) has signed a letter of intent with renewable energy developer Juniper Energy to deploy 500 megawatt-hours (MWh) or more of sodium-ion battery storage by 2032, according to CleanTechnica. The agreement, announced 22 July, according to Energy-Storage.News, begins with a 10 MW / 80 MWh project in California targeted for commercial operation in 2027.
What We Know
- The letter of intent (LOI) “outlines a long-term framework under which ESS and Juniper could work together on multiple energy storage projects,” according to Interesting Engineering, which reported the deal as a “preliminary agreement” rather than a binding purchase commitment.
- Energy-Storage.News confirmed the pact is a non-binding LOI and reported that, contingent on successful execution and future development, Juniper Energy intends to procure at least 500 MWh of ESS battery energy storage systems by 2032.
- The initial project will use ESS’s Bridge modular sodium-ion AC solution paired with an ESS Energy Management System, and is expected to be operational in 2027, according to Energy-Storage.News and CleanTechnica.
- Juniper Energy is a “California-based renewables developer,” according to Energy-Storage.News.
- “This agreement with Juniper Energy validates ESS’s strategy to expand our technology portfolio and bring sodium-ion energy storage to market,” said Drew Buckley, CEO of ESS, according to CleanTechnica and Interesting Engineering. “The planned deployment and long-term procurement framework reflect the accelerating customer demand we are seeing for safer, domestically sourced alternatives to conventional lithium-ion batteries.”
- “Juniper Energy is focused on partnering with companies that can successfully bring innovative energy technologies from development into commercial operation,” said Keith McDaniels, Managing Partner of Juniper Energy, according to CleanTechnica and Interesting Engineering. “ESS has demonstrated its ability to integrate, deploy, and scale advanced energy storage solutions, giving us confidence in its ability to execute on next-generation sodium-ion technology.”
- Sodium-ion systems rely on sodium and other more abundant materials than lithium-ion batteries, which Interesting Engineering reported could reduce exposure to supply chain constraints tied to critical battery minerals.
What We Don’t Know
- Because the agreement is a non-binding letter of intent, the 500 MWh procurement figure is a stated intent rather than a guaranteed order, and both outlets note it is contingent on the California project and future development succeeding.
- Neither ESS nor Juniper Energy has disclosed pricing, financing terms, or additional project sites beyond the initial California deployment.
Analysis
The deal lands amid a broader push by US grid operators and developers toward non-lithium storage chemistries, driven partly by a desire for domestically sourced battery materials. ESS has historically marketed itself around iron flow battery technology; the Juniper Energy agreement extends that non-lithium positioning into sodium-ion, a chemistry also being pursued at commercial scale by larger manufacturers such as CATL and BYD. Whether the framework converts into the full 500 MWh Juniper Energy has signaled interest in will depend on the performance of the 80 MWh California pilot project once it comes online in 2027.