Slide 1: Q3 2025 Earnings Presentation
Q3 2025 Earnings Presentation November 2025
Slide 2: Disclaimers
Disclaimers This presentation includes forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended (the “Securities Act”) and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). These forward-looking statements can be identi
Slide 3: Operating Highlights
Operating Highlights Catalyzing a Clean Future. Every Day.
Slide 4: New Product Launched: The Energy Base
New Product Launched: The Energy Base No Containers Endless Flexibility No Limits Catalyzing a Clean Future. Every Day. ESS Tech, Inc. 3
Slide 5: The Energy Base: Powered by the Iron Core
The Energy Base: Powered by the Iron Core • At the heart of each Energy Base project is a configurable set of modular powertrains, called the Iron Core, engineered to deliver gigawatt-hour storage capacity for your next project. • Built with our proven iron flow battery modules and established core
Slide 6: The Energy Base: Iron Core Building Blocks
The Energy Base: Iron Core Building Blocks Infinitely scalable to meet project size and specifications THE IRON CORE A Repeatable Building Block •A Power Platform: Existing iron flow C battery modules, used in the Energy Center today, arranged in integrated skids for easy transport and installation
Slide 7: The Energy Base: Product Strategy
The Energy Base: Product Strategy ESS continues to manufacture core technology in-house while balance of system is procured directly from preferred vendors EPC & Developer Partners Electrolyte Iron Core Electrolyte Iron Core Plumbing Design Tanks Enclosure & Mechanical Specifications ESS manufacture
Slide 8: The Energy Base: Honeywell Partnership
The Energy Base: Honeywell Partnership Relationship & Role • ESS Investor and Customer; exploring product collaboration on the Energy Base • Joint Development Agreement (illustrative projects) - Porous electrode - Efficiency enhancers - Fluid flow innovations (new pump types and routing) • Procureme
Slide 9: Extending Duration Up to 22 Hours with the Energy Base
Extending Duration Up to 22 Hours with the Energy Base ESS can scale both duration and capacity independently to meet customer specifications using established core technology Power Capacity (MW) ESS iron flow battery modules are capable of storing up to 22 hours of energy, but previous product de
Slide 10: Rapidly Expanding Need for Storage Across Grid Operators & Hyperscalers
Rapidly Expanding Need for Storage Across Grid Operators & Hyperscalers Market Need Global Electricity Demand for Data Centers, AI and Cryptocurrency (TWh)1,2 • Data centers require safe, resilient and sustainable High Case High & power delivery to ensure Base Case Growing uptime (Uninterruptible Ne
Slide 11: ESS Products Meet Data Centers' Growing Electricity Needs
ESS Products Meet Data Centers’ Growing Electricity Needs THE SOLUTION: ESS Energy Base (“EB”) Causes of Impactful Data Center Outages1 • Enables fast deployment of additional grid capacity Other Enhances Grid (solar + EB) 10% Power • Increases grid balancing and resilience of supply for Network Cap
Slide 12: Tailored Solutions to Bring Value to Data Center Customers
Tailored Solutions to Bring Value to Data Center Customers ESS Data Center Value Proposition Project Configuration Options Standalone Iron- Enables continuous peak Flow Battery (“IFB”) Flexible Grid-tied long-duration storage shifting ensuring critical Storage Cycling customers receive power to enha
Slide 13: Expansion of Wilsonville Manufacturing Capacity
Expansion of Wilsonville Manufacturing Capacity Addition of new lines to meet customer demand supports mix shift towards more capital efficient and lower unit cost Energy Base product ESS is currently in the process of commissioning its second automated battery manufacturing line (“Line 2”) and wi
Slide 14: ESS Superior Value Proposition vs. Li-ion
ESS Superior Value Proposition vs. Li-ion Several favorable attributes of ESS technology vs. Li-ion result in lower LCOS and costs to customers over the long-term Competitive Upfront Ongoing Ownership Superior Operating Installed Cost Advantages Characteristics S T R O N G E R C AP AC I T Y P R O F
Slide 15: Financial Results
Financial Results Catalyzing a Clean Future. Every Day.
Slide 16: Q3 2025 Results
Q3 2025 Results ($ in millions) Q3 2025 Q3 2024 Change (%) Q3 2025 Highlights Revenue $0.2 $0.4 (40%) Gross Profit (Loss) ($4.7) ($12.4) 62% Continued reductions in cost of revenue and Operating Expenses $5.1 $11.3 (55%) operating expenses reflective of cost reduction efforts Profit (Loss) from Oper
Slide 17: Reconciliation of Q3 2025 GAAP Net Loss to Adjusted EBITDA
Reconciliation of Q3 2025 GAAP Net Loss to Adjusted EBITDA Three Months Ended Three Months Ended ($ in thousands) September 30, 2025 September 30, 2024 Net loss ($10,375) ($22,493) Interest (expense) income, net 456 (807) Stock-based compensation 1,041 2,658 Depreciation and amortization 1,486 781 G
Slide 18: Cash & Financing: Q3 2025
Cash & Financing: Q3 2025 Cash & Financing Update ($ in millions) 9/30/2025 6/30/2025 Change Significant reduction in operating cash burn rate – down Cash1 & Investments 3.5 0.8 2.7 approximately 50% from Q2 2025 In July, launched $25M Standby Equity Purchase Other Liquid Assets Agreement (SEPA)
Slide 19: ESS: An Enduring Value Proposition
ESS: An Enduring Value Proposition ESS delivers the safe, market leading, long-duration energy storage solutions that empower our customers to make their clean energy vision a reality. Flexible Technology Powered by Nature Responsible and Equitable ESS’ scalable solutions serve Iron. Salt. Water. Do
Slide 20: Thank You
Thank You