FIRST QUARTER 2017 REVIEW MAY 4, 2017 FORWARD-LOOKING STATEMENTS - PowerPoint PPT Presentation

FIRST QUARTER 2017 REVIEW MAY 4, 2017

FORWARD-LOOKING STATEMENTS Cau auti tionary State Statement R t Regarding F Forward-Looking State Statements ts This presentation contains statements reflecting assumptions, expectations, projections, intentions or beliefs about future events that are intended as “forward looking statements.” You can identify these statements by the fact that they do not relate strictly to historical or current facts. Management cautions that any or all of Dynegy’s forward- looking statements may turn out to be wrong. Please read Dynegy’s annual, quarterly and current reports filed under the Securities Exchange Act of 1934, including its 2016 Form 10-K and first quarter 2017 Form 10-Q, when filed, for additional information about the risks, uncertainties and other factors affecting these forward-looking statements and Dynegy generally. Dynegy’s actual future results may vary materially from those expressed or implied in any forward- looking statements. All of Dynegy’s forward-looking statements, whether written or oral, are expressly qualified by these cautionary statements and any other cautionary statements that may accompany such forward-looking statements. In addition, Dynegy disclaims any obligation to update any forward-looking statements to reflect events or circumstances after the date hereof. Non on-GAAP AP F Financia ial M l Measures This presentation contains non-GAAP financial measures including EBITDA, Adjusted EBITDA and Adjusted Free Cash Flow. Reconciliations of these measures to the most directly comparable GAAP financial measures to the extent available without unreasonable effort are contained herein. To the extent required, statements disclosing the definitions, utility and purposes of these measures are set forth in Item 2.02 to our current report on Form 8-K filed with the SEC on May 4, 2017, which is available on our website free of charge, www.dynegy.com. 2

TABLE OF CONTENTS I. Overview and Outlook II. Operations and Commercial Activities III. First Quarter 2017 Financial Results IV. Summary 3

OVERVIEW AND OUTLOOK • 1Q 2017 Net Income of $597 MM versus $10 MM of Net Loss for 1Q 2016 1Q 2017 • 1Q 2017 Adjusted EBITDA of $230 MM versus $251 MM for 1Q 2016 FINANCIAL HIGHLIGHTS • Available liquidity of $1,366 MM as of March 31, 2017 • Second round of bidding underway for the sale of Dynegy assets to meet FERC’s market mitigation requirement in Southeastern New England PORTFOLIO • Received early termination of the Hart-Scott-Rodino Act waiting period for Armstrong and TRANSFORMATION Troy sale • Agreed to purchase remaining ownership interests in Miami Fort and Zimmer • Stuart and Killen facilities announced for retirement • Callable in May 2017 at 103.375; currently trading above par 2019 UNSECURED • Free cash flow, proceeds from announced and in-process asset sales and existing liquidity DEBT MATURITY sufficient to to repay th the enti tire m matu aturity ty • Reaffirming 2017 Adjusted EBITDA guidance range of $1,200 – 1,400 MM 2017 GUIDANCE • Raising 2017 Adjusted Free Cash Flow guidance range from $150 – 350 MM to $300 – 500 MM • ~90% of 2017 gross margin from capacity sales, tolls, retail and hedged energy margin 4 (1) Note: Adjusted EBITDA and Adjusted Free Cash Flow are non-GAAP measures; reconciliations to GAAP can be found in the Appendix

POSITIVE MOVEMENT IN KEY AREAS  Visible pathway to repaying the maturity without reliance on capital markets 2019 DEBT Many options available to further enhance liquidity  MATURITY  Beyond 2019 bonds, no major maturities until 2022  Interest expense of $142 M $142 MM per year reduced as debt is repaid FERC and ISOs acknowledge negative impact from subsidies on  competitive markets  FERC Technical Conference on May 1-2, 2017  PJM capacity market proposal to offset impact of subsidies made MARKET DESIGN public on May 2, 2017 − Capacity Price Sensitivity: $10/M $10/MW-day = = ~$45 ~$45-50 M 0 MM ISO-NE capacity market proposal to offset impact of subsidies  made public on April 24, 2017 − Capacity Price Sensitivity: $1/k $1/kw-mont nth = = ~$45 ~$45 MM  Under existing rule, Dynegy will defer spend by at least two years Stuart and Killen retirements eliminate future ELG spend; cleared  capacity revenues reassigned to other Dynegy plants ELG CAPITAL SPEND  On April 12, 2017, ELG rule remanded back to EPA for further evaluation - potential for further delays and/or spending adjustments to forecasted spend of $252 M $252 MM (as disclosed in DYN’s First Quarter 2017 10-Q) 5

OPERATIONS AND COMMERCIAL OVERVIEW

OPERATIONS SUMMARY Rac achel C Cas asey Safety Performance - Total Recordable Incident Rate (TRIR) Generation Volumes (MM MWh) IPH MISO PJM NY/NE CAISO ERCOT 1Q16 1Q17 25.5 24.2 0.6 3.08 0.7 0.3 4.7 3.9 1.95 13.3 12.9 12.6 0.4 10.9 13.4 0.7 13.0 0.2 1.50 0.3 1.0 3.1 0.8 3.7 4.9 1.03 3.5 2016 EEI 0.70 2.7 2.7 3.3 3.3 9.5 8.5 top-decile TRIR (1.09) 3.8 3.8 3.3 3.3 0.00 1Q16 1Q17 1Q16 1Q17 1Q16 1Q17 (1) (1) Gas Coal Total Gas Coal Consolidated Net Capacity Factors Operations Update Safe fety P Perform rformance 1Q16 1Q17 Total Dynegy safety performance in the top decile • Gas fleet continues to perform at high level • Coal fleet performance improved over 50% due to focused safety • initiatives 65% Generation ion Vo Volumes es 55% Gas fleet decreased due to lower spark spreads and more • outages in 1Q 2017 44% 42% Coal fleet increased primarily due to favorable pricing and fewer • outages in 1Q 2017, offset by retirements Net t Cap apac acity ty F Fac actors Gas fleet declined primarily due to introduction of the ENGIE • ERCOT fleet, increased outages and lower spark spreads (3) (2) Coal fleet increased primarily due to favorable pricing and fewer Gas (CCGT) Coal • outages 7 (1) Excludes corporate and retail personnel; (2) 1Q16 excludes Casco Bay (Facility was under a tolling arrangement which expired 12/31/16); (3) Excludes Brayton Point

IMPROVING OUR ENVIRONMENTAL PROFILE Declining Greenhouse Gas (GHG) Intensity Rac achel C Cas asey Coal Combustion Byproduct Reuse on the Rise (1) 3 90% 2,000 on (MM tons) 80% 1,800 70% CO2 (lb/MWh) 2 60% 1,600 roduction % R 50% Reuse 40% 1,400 Prod 1 30% Ash P Ash 1,200 20% 10% 1,000 0 0% 2014 2015 2016 2017E 2014 2015 2016 2017E Average CCGT GHG Intensity Dynegy GHG Intensity Ash Production Ash Reuse % Reuse Declining SO2 and NOx Impact (lbs/MWh) Highlights Transformation to a predominantly gas generation portfolio • SO2 (lbs/MWh) NOx (lbs/MWh) 2.0 driving reduced carbon footprint and emissions reductions Lowering our emissions profile reduces exposure to current • 1.5 and future regulations 100% goal for beneficial reuse of coal ash by 2020 • 1.0 Benefits of reusing coal ash: • − Reduces CO 2 by using ash to replace cement and other 0.5 products − Reduces costs associated with handling and storage of 0.0 ash 2014 2015 2016 2017E − Provides incremental revenue Portfolio transformation has a favorable impact on Dynegy’s emissions profile 8 (1) Excludes non-operated plants

PRIDE ENERGIZED (2016-2018) PRIDE Energized EBITDA ($ MM) 2017 PRIDE EBITDA Initiatives Progress $65 MM in 2017 EBITDA initiatives have been identified 2016 Results to date: of $150 MM Coal and transportation contract reductions • $50 Gas transport rate reduction • $65 Gas turbine uprates (incremental to 2016) • $250 $135 2016 2017 2018 Total PRIDE Energized Balance Sheet ($ MM) 2017 PRIDE Balance Sheet Initiatives Progress Despite already exceeding our three year target in 2016 Results of $422 MM PRIDE balance sheet initiatives, Dynegy continues to find additional opportunities with over $75 MM in new initiatives identified in 2017: $100 South Bay lease LC reduction • Term loan repricing • $100 $400 Tax credit monetization • Railcar LC reduction • $200 2016 2017 2018 Total PRIDE Energized remains on track to meet 2017 targets and three year goal 9