#1Eos Energy Enterprises, Inc. NASDAQ: EOSE Company Presentation. June 2023 Eos. Positively ingenious. eos#22 Disclaimers Forward-Looking Statements. This presentation includes "forward-looking statements" within the meaning of the "safe harbor" provisions of the Private Securities Litigation Reform Act of 1995. The actual results of Eos Energy Enterprises, Inc. ("Eos") may differ from its expectations, estimates and projections and consequently, you should not rely on these forward-looking statements as predictions of future events. Words such as "expect", "estimate", "project", "budget", "forecast", "anticipate", "intend", "plan", "may", "will", "could", "should", "believe", "predict", "potential", "continue", and similar expressions are intended to identify such forward-looking statements. These forward-looking statements involve significant risks and uncertainties that could cause the actual results to differ materially from current expectations. Factors that may cause such differences include, but are not limited to: the preliminary financial information remains subject to changes and finalization based upon Eos's ongoing review of results for the fourth quarter and full fiscal year 2022 and the completion of all quarter and year end closing procedures; Eos's ability to secure financing to continue expansion; changes adversely affecting the business in which we are engaged; our ability to forecast trends accurately; our ability to generate cash, service indebtedness and incur additional indebtedness; our ability to raise financing in the future; uncertainties around the final tax credits available to our customers or to Eos pursuant to the Inflation Reduction Act, uncertainties around our ability to secure conditional commitment or final approval of a loan from the Department of Energy or the final amount of any loan; our ability to develop efficient manufacturing processes to scale and to forecast related costs and efficiencies accurately, and to secure labor; fluctuations in our revenue and operating results; competition from existing or new competitors; the failure to convert firm order backlog and pipeline to revenue; the failure to sufficiently reduce manufacturing costs, potential delays in the launch of Eos's Z3 battery; inefficient implementation of the Inflation Reduction Act of 2022; risks associated with security breaches in our information technology systems; the risk of a government shutdown as Eos remains in due diligence on its loan application with the U.S. Department of Energy Loan Programs Office; risks related to legal proceedings or claims; the outcome of any legal proceedings that may be instituted against Eos; risks associated with evolving energy policies in the United States and other countries and the potential costs of regulatory compliance; risks associated with changes to U.S. trade environment; risks resulting from the impact of global pandemics, including the novel coronavirus, Covid-19; the ability to maintain the listing of Eos's shares of common stock on NASDAQ; the ability of Eos's business to grow and manage growth profitably, maintain relationships with customers and suppliers and retain its management and key employees; risks related to the inflationary economic environment; risk from supply chain disruptions and other impacts of geopolitical conflict; changes in applicable laws or regulations; the possibility that Eos may be adversely affected by other economic, business, and/or competitive factors and other factors beyond our control; risks related to adverse changes in general economic conditions; and other risks and uncertainties indicated in the company's most recent annual report on Form 10-K and subsequent reports on Forms 10-Q and 8-K, including those under the heading "Risk Factors" therein, and other factors identified in Eos's prior and future SEC filings with the SEC, available at www.sec.gov. Eos cautions that the foregoing list of factors is not exclusive and not to place undue reliance upon any forward-looking statements, which speak only as of the date made. Moreover, Eos operates in a very competitive and rapidly changing environment, and new risks and uncertainties may emerge that could have an impact on the forward-looking statements contained in this presentation. Eos does not undertake or accept any obligation to release publicly any updates or revisions to any forward-looking statements to reflect any change in its expectations or any change in events, conditions or circumstances on which any such statement is based. Preliminary Financial Information. This presentation includes certain unaudited preliminary financial information as of and for the fourth quarter and year ended December 31, 2022, including revenue and cash (excluding restricted cash). Our independent registered public accounting firm has not audited, reviewed, compiled or completed its procedures with respect to this preliminary financial information. Our actual results may differ from these estimates as a result of the completion of our audit and other developments that may arise between now and the time our financial results for the fourth quarter and year are finalized. No Offer or Solicitation. This presentation shall not constitute an offer to sell or the solicitation of an offer to buy any securities, nor shall there be any sale of securities in any states or jurisdictions in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such jurisdiction. No offering of securities shall be made except by means of an exemption from the Securities Act of 1933, as amended. Confidentiality. This presentation and the accompanying oral presentation are strictly confidential. Each recipient of this presentation agrees that neither it nor its agents, representatives, directors or employees will copy, reproduce or distribute to others this presentation, in whole or in part, at any time without the prior written consent of Eos and that it will keep permanently confidential all information contained herein not already in the public domain. Industry and Market Data. In this presentation, we rely on and refer to information and statistics regarding market participants in the sectors in which Eos competes and other industry data. We obtained this information and statistics from third party sources, including reports by market research firms and company filings. We have not independently verified the accuracy or completeness of, and disclaim and liability with respect to, such third-party sources and the data therein that have been included in this presentation. Trademarks. This presentation may contain trademarks, service marks, trade names and copyrights of other companies, which are the property of their respective owners. Solely for convenience, some of the trademarks, service marks, trade names and copyrights referred to in this presentation may be listed without the TM, SMO or ® symbols, but Eos will assert, the fullest extent under applicable law, the rights of the applicable owners, if any, to these trademarks, service marks, trade names and copyrights. Znyth, Eos Znyth, and Eos Z3 are trademarks of Eos Energy Technology Holdings, LLC, wholly owned subsidiary of Eos Energy Enterprises, Inc. Key Metrics Backlog. Our backlog represents the amount of revenue that we expect to realize from existing agreements with our customers for the sale of our battery energy storage systems and performance of services. The backlog is calculated by adding new orders in the current fiscal period to the backlog as of the end of the prior fiscal period and then subtracting the shipments in the current fiscal period. If the amount of an order is modified or cancelled, we adjust orders in the current period and our backlog accordingly, but do not retroactively adjust previously published backlogs. There is no comparable US-GAAP financial measure for backlog. We believe that the backlog is a useful indicator regarding the future revenue of our Company. Pipeline. Our pipeline represents projects for which we have submitted technical proposals or non-binding quotes plus customers with letters of intent ("LOI") or firm commitments. Pipeline does not include lead generation projects. Booked Orders. Booked orders are orders where we have legally binding agreements with a Purchase Order ("PO") or Master Supply Agreement ("MSA") executed by both parties. eos.#3Today's Presenters 3 Joe Mastrangelo Chief Executive Officer Nathan Kroeker Chief Financial Officer eos#4Clean Energy Storage that Defies Convention 4 From our patented battery chemistry to our commonsense manufacturing process, Eos' operating benefits deliver a significant reduction in levelized cost of storage (LCOS) Safe eos Scalable (1) Numbers shown as of 3/31/23 (2) For the three months ended 3/31/23 Sustainable (3) Numbers shown as of 4/24/23 (4) 3/31/23 Cash balance (excluding restricted cash) does not include - $63M raised in Q2 2023 ✓ Founded in 2008, 300+ team members ✓ Technology optimized for 4+ hour storage ✓ Zinc electrolyte-based chemistry; No rare earth minerals required ✓ Fully recyclable and non-flammable ✓ Designed and manufactured in U.S. ✓ More than 95 patents pending, issued, or published in 23 countries ✓ Scaling to Gigawatt-hour annual production capacity By the Numbers Opportunity Pipeline¹ $8.5B Representing 32 GWh Discharge Energy³ 1.4 GWh Booked Orders² $86.3 M Representing 347 MWh Revenue² $8.8 M Orders Backlog1 $535.1 M Representing 2.2 GWh Cash on hand4 -$16.1M eos#5GWh total energy discharged in the field 700 MWh Discharged 2023 Year to Date Enough to Power 140,000 homes for 4 hours#6Market Overview 6 eos#7The Energy Storage Market is Primed for Growth Estimated Domestic GWh to be Installed by 2025¹ 44 GWh 7 2015 121 GWh US Installs Annual US Storage Capacity Additions, pre/post IRA (GWh) 55 GWh Historial Pre IRA Post IRA 25 GWh 2020 IRA Passed 2025 (1) Bloomberg NEF 2H 2022 Energy Storage Market Outlook (2) Wall Street Research (3) Wood Mackenzie Power & Renewable 4 GWh 2030 Eos Target States Significant Opportunity for Eos to capture market share by focusing on 3 key states CAISO energy storage queue of 31 GW ✓ California Energy Commission awarded grant for Eos LDES; 35 MWh project to be shipped in 2023 ERCOT energy storage queue of 66 GW ✓ Eos existing customer base targeting ERCOT projects NYSIO energy storage queue of 13.7 GW ✓ State of New York released energy storage roadmap of getting to 6 GW by 2030 Regulatory and Policy Tailwinds are Driving Demand Globally² *+ MW Significant Opportunity for Eos International Market Expansion Announced Green Deal Industrial Plan Global Net Zero Pledges 2050 $3.5B Climate Solutions Package 2050 2070 Global Energy Storage Annual Capacity (GW) (Estimated) 100000 90000 80000 70000 60000 50000 40000 30000 20000 10000 0 LI 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 3 eos.#8Energy Storage Market Segmentation Multiple technologies required to meet dynamic use cases. Duration Market size ¹ Applications Customer needs Round Trip Efficiency (RTE) 8 100% 75% 50% Short 0-3 hours Lithium ion 34 GWh Ancillary services Energy arbitrage Demand charge reduction High power High round trip efficiency (RTE) Zinc Hybrid (1) Proprietary, 3rd party distributed storage market model Medium (Intraday) 3-12 hours 115 GWh Renewable energy shifting Flexibility Simplicity Safety Flow Batteries Compressed Air (CAES) T TESLA Panasonic BYD Thermal Storage Liquified Air (LAES) Long (Interday) 12+ hours eos 125 GWh Capacity + seasonal flexibility Grid resiliency Low marginal cost of adding energy at the same power Aqueous Batteries ESSING H HYDROSTOR MALTA Highview Power® Form energy eos#9Eos' Proprietary Technology 9 eos#10A Zinc-Based Aqueous Electrolyte Static Battery A proprietary battery designed specifically for the 3- to 12-hour grid storage market 10 ✓ Simple ✓ Safe ✓ Durable ✓ Flexible ✓ Local 1 Non-degradable bipolar electrodes Conductive plastic & carbon-felt 2 High-performance aqueous electrolyte Innovative blend of water, halides, additives, & buffering agents 3 Fully-sealed polymer casing Rugged, injection-molded exterior H 1 eos#11Gen 2.3: The Last 12 Months Rapidly ramped production to deliver largest customer project to date March 2022 New manufacturing facility construction begins; 2 welders online 11 (1) From 4/2022-3/2023 (2) Completed on April 25, 2023 34k+ Batteries produced 1 eos eos 208 Energy Blocks shipped 1 46 MWh Completed 4-hour cycle on Pine Gate Eastover system 2 eos 18 April 2023 Transitioning manufacturing to Eos Z3TM; Gen 2.3 manufacturing limited to service / spares eos#12A Simpler & Lower Cost System - The Eos Z3TM Battery Eos' remaining backlog will be delivered with the Z3 battery, which results in a 50% + cost-out opportunity at launch + + + + 12 Simplicity & Density 50% fewer cells per module Replacing titanium with conductive polymer for lower weight and cost Enhancing aqueous zinc electrolyte resulting in 12.5% higher discharge voltage 2x increase in energy density Manufacturability + Automating battery and semi- automating container assembly + 98% fewer welds per battery reduces cycle time with higher yields + Battery module cycle time reduced from 55 minutes to less than a minute $/kWh Lower Cost Structure Launch + Production 1 Gen 2.3 Z3 Z3 w/ Production Tax Credits Scale 50% + cost-out opportunity at product launch eos#13Operational Excellence TM Eos Z3™ Battery Manufacturing 3 stage process to scale manufacturing and optimize CAPEX investment 1 13 Discrete Manufacturing Operations Q4 '22-Q1 '23 1M $ CAPEX 58.. investment *Annual capacity DAKE ANETETZE F 110 MWh capacity* 2 Semi-Automated Manufacturing Cells Q2 Q3 '23 HOTENSTEIN DUKANE 5-7M $ Forecasted CAPEX 540 MWh capacity* 3 Fully Automated Manufacturing Line Q4 '23-Q1 '24 40-50M $ Forecasted CAPEX 1.25 GWh capacity* eos#14Financial Highlights 14 eos#15Financial Highlights 15 Shares Outstanding as of 3/31/2023 Cash Balance on 3/31/2023 Debt Balance on 3/31/2023 2021 Capitalization Summary 2022 2023 2021-2023 Funding Summary Koch Trinity Capital Atlas Credit Partners Yorkville Advisors ATM 3 Trinity Capital Existing Investors Yorkville Advisors 2 Investors 2 Investors 3 Total 2021-2023 Funding ³ Convertible Note Equipment Financing IP-Backed Senior Secured Debt SEPA At-The-Market Program Equipment Financing Convertible Note SEPA Direct Offering Direct Offering 2 95.2M $16.1M $236.8M $100M $7M $100M $14.5M $39.8M $4.2M $13.75M $36.25M $40M $8M $363.5M 3.3 Revenue $ in millions Q1 2022 Q1 2022 (51.7) L +168% Operating Loss $ in millions (1) 3/31/23 Cash balance (excluding restricted cash) as reported on Form 10-Q published on May 9, 2023 does not include ~$63M raised in Q2 2023 All numbers are reported gross numbers exclusive of any fees or commissions. (2) (3) As of May 18, 2023 7 8.8 +26% Q1 2023 Q1 2023 (38.3) ■ ■ 17.1 Cash $ in millions Q1 2022 -6% 16.1 Q1 2023 1 Operating Losses Driven By: Significant investment in capacity expansion to meet customer demand Investment in Z3 development and product launch readiness eos.#16Financial Results Progress Against 2023 Objectives $600-800M in booked orders 16 $30-50M in revenue 15% product cost reduction from Z3 launch + Current opportunity pipeline increased $1B from Q4 '22 + Signed 3 new Letters of Intent for 850 MWh Demand surging, 21% energy storage CAGR through 20301 + Q1 revenue of $8.8M includes final Gen 2.3 new build shipments + Focused on shifting manufacturing to Eos Z3TM with a 2H ramp + Forecasting $45-60M capacity investment over next 12 months + Identified 7 key projects in design optimization & supply chain improvements + Improving battery density, eliminating titanium & simplified system design + Strategic supplier relationships + component mfg insourcing opportunities (1) Global energy storage deployments Compound Annual Growth Rate, Bloomberg NEF 2H 2022 Energy Storage Market Outlook eos.