Slide 1: Second Quarter 2026 Financial Results Conference Call
Catalyzing a Cleaner Future. Every Day. Second Quarter 2026 Financial Results Conference Call Sodium-ion and iron flow energy storage for utility, data center, defense and infrastructure customers. Earnings Conference Call NYSE: GWH August 11, 2026
Slide 2: Disclaimers
Disclaimers No part of this presentation may be reproduced, photocopied, redistributed or passed on, directly or indirectly, to any other person, or published, in whole or in part, for assumptions. The Company has not independently verified this information, and it involves a number of assumptions a
Slide 3: Agenda
Agenda Second Quarter 2026 Earnings Call ON THE CALL TODAY 1 Corporate Overview Platform, products and positioning 2 Operational Highlights Q2 business updates and commercial progress 3 New Product — Bridge The modular sodium-ion battery energy storage system 4 Business Combination Proposed transact
Slide 4: Corporate Overview
Corporate Overview ESS is an energy storage company specializing in sodium- ion and iron flow battery technology. • Bridge sodium-ion BESS: a 1.2 MWh AC modular block for short- and medium- duration storage. • Energy Base iron flow: 10- to 20-hour+ long-duration systems for 24/7 renewable power. • E
Slide 5: Q2 2026 and Subsequent Highlights
Q2 2026 and Subsequent Highlights An inflection quarter: AI-driven demand accelerating sodium-ion to complement iron flow. WHY NOW: 2x U.S. data center power demand by 2030 & 20–25 GW of batteries expected inside data centers by 2030 SODIUM-ION ACCELERATION COMPANY UPDATES ● Announced the accelerati
Slide 6: Bridge — A Modular Sodium-Ion BESS
Bridge — A Modular Sodium-Ion BESS Purpose-built for AI data center duty cycles. First module built and in testing at Wilsonville. BUILT FOR AI LOADS: GPU clusters swing tens of megawatts in seconds. Bridge delivers high-rate cycling where lithium degrades. 1.2 4.8 2–16 20 MWh PER BLOCK MWh PER 20-F
Slide 7: Commercial Momentum
Commercial Momentum Signed sodium-ion commitments alongside broadening interest from existing and prospective customers. SODIUM-ION · NEW CUSTOMER ENGAGEMENT SUPPLY Juniper Energy Existing & New Customers Alsym Energy 500+ MWh Growing Opportunities 8.5 GWh Letter of Intent signed subsequent to quart
Slide 8: Proposed Business Combination
Proposed Business Combination Non-binding letter of intent signed August 6, 2026 • Established, revenue-generating operating platform with a track record of proven commercial execution • Combined enterprise value of approximately $515 million • Premium to ESS market capitalization at signing of the
Slide 9: Financial Results
Financial Results Spending reallocated toward the sodium-ion platform as legacy contracts wind down. ($ in millions, except per share data) Q2 2026 Q2 2025 Change (%) Q2 2026 Financial Highlights Revenue $0.1 $2.4 (97%) Cost of Revenue $7.5 $7.5 n/m • Loss per share improved 49% year-over-year to $(
Slide 10: Reconciliation of GAAP Net Loss to Adjusted EBITDA
Reconciliation of GAAP Net Loss to Adjusted EBITDA ($ in millions) Q2 2026 Q2 2025 Change (%) Net loss $ (15.6) $ (11.1) (41%) Q2 2026 Highlights Interest expense (income), net $0.6 $ (0.0) (2,087%) • First-half loss from operations improved 3% Stock-based compensation $0.7 $1.7 (59%) year-over-year
Slide 11: Cash & Financing
Cash & Financing Continued reduction in operating cash burn alongside disciplined capital allocation. ($ in millions) 6/30/26 12/31/25 Change Cash & Financing Update Cash¹ $10.8 $14.5 $ (3.6) • First-half operating cash use declined 27% Short-term Investments $— $7.6 $ (7.6) year-over-year to $22.4
Slide 12: Closing Summary
Closing Summary Commercial Momentum • Letter of intent for a proposed business combination with a private company in the energy sector with expected combined enterprise value of approximately $515 million • Juniper Energy LOI for 500+ MWh; 10 MW / 80 MWh California anchor project • Alsym Energy LOI
Slide 13: Questions & Answers
NYSE: GWH Questions & Answers Catalyzing a Cleaner Future. Every Day. COMPANY INVESTOR RELATIONS ESS Tech, Inc. Chris Tyson 26440 SW Parkway Ave, Bldg. 83 Executive Vice President, MZ Group — MZ North America Wilsonville, OR 97070 (949) 491-8235 investors@essinc.com GWH@mzgroup.us essinc.com