Acquisition of MACH Gen, LLC 2.5 GWs of Efficient Gas-Fired Generation

We Generate Energy for a Brighter Tomorrow Acquisition of MACH Gen, LLC 2.5 GWs of Efficient Gas-Fired Generation July 2015 Investor Presentation

Safe Harbor Forward Looking Statements: Any statements made in this presentation about future operating results or other future events are forward-looking statements under the Safe Harbor Provisions of the Private Securities Litigation Reform Act of 1995. Actual results may differ materially from such forward-looking statements. A discussion of factors that could cause actual results or events to vary is contained in the Supplemental Information to this presentation and in the Company s SEC filings, including the factors discussed under Risk Factors in the Company s Registration Statement on Form S-1. Talen Energy Corporation 2015 2

Agenda Transaction Highlights MACH Gen Overview Financial Considerations Closing Remarks and Q&A P. Farr P. Farr J. McGuire P. Farr Talen Energy Corporation 2015 3

Creating Value from Day 1 Talen Energy Corporation 2015 4

Executing on the Growth Strategy Strategic Priorities Communicated at Spin 50 Days Ago: MACH Gen: 1 2 3 4 5 Grow asset base in accretive manner Extend track record of originating transactions Expand presence in attractive markets Further diversify fuel mix Take advantage of cash taxpayer status Talen Energy Corporation 2015 5

Transaction Highlights Fleet Diversification + Immediate Cash Flow Accretion (1) Acquiring 2.5 GW MACH Gen portfolio for $1.175 billion, in a negotiated deal, including significant tax attributes Achieving goal of growth in key markets and fuel diversity with high quality assets Efficient Siemens 501G machines, with fleet benefits to Talen Energy s Ironwood and Lower Mount Bethel stations Substantial, immediate free cash flow accretion of over 10% Significant value from optimizing the Harquahala station (2) (1) Includes $13 million of inventory (2) Based upon projected 2016E Adjusted Free Cash Flow assuming close by 12/31/2015 Talen Energy Corporation 2015 6

Achieving Strategic Objectives Adding scale in key markets that favorably diversifies fuel mix and improves cash flow profile Strategic Highlights Scale: Increases pre-mitigation generating capacity 17% to approximately 17.6 GWs Geographic Diversity: Growth in NYISO and ISO-NE, two mature and liquid wholesale power markets Fuel Diversity: Reduces solid fuel exposure Coal capacity from 40% to 34% Natural gas capacity from 40% to 49% Immediately Free Cash Flow (FCF) Accretive: Efficient asset portfolio that produces substantial FCF 3% 2% 18% 15% 22% 40% Diversifying the Fuel Mix 100% 16% Pro Forma 2% 2% 13% 33% 15,060 MW 2,527 MW 17,587 MW 34% Coal Natural Gas Dual Fuel Nuclear Oil Hydro/Renewables (1) Immediate FCF Accretion Adjusted Free Cash Flow 2016E Pre-Transaction free cash flow $290 Transaction free cash flow $30 Expanding in Key Markets: ISO-NE & NYISO Pro Forma 1% 4% 2% 9% 13% 12% 7% 42% 11% Post-Transaction free cash flow $320 83% 45% 71% Free cash flow accretion ($) $30 Free cash flow accretion (%) 10.3% 15,060 MW 2,527 MW 17,587 MW PJM ERCOT NYISO ISO-NE WECC Notes: Assumes transaction close by 12/31/2015. Does not reflect sale of approximately 1,300 MW of generating capacity that is required to comply with the FERC Order or immaterial renewable capacity that Talen Energy has agreed to sell. Refer to Supplemental Information Regulation G Reconciliations for reconciliation of non- GAAP financial measures (1) Reflects EIA reported summer capacity ratings Talen Energy Corporation 2015 7 (1)

MACH Gen Overview Talen Energy Corporation 2015 8

MACH Gen Portfolio Portfolio Highlights Attractive low heat rate CCGT portfolio of scale with over 2.5 GW of generating capacity Relatively new portfolio with well maintained units CODs ranging from 2001-2004 Proven operating track record substantial past investment to improve operations and reliability has resulted in a 3 year availability factor of over 93% Well-positioned to benefit from infrastructure developments and improving market dynamics Diverse Geographic Footprint ME AZ VT NH MA 3 NY 1 2 CT RI Portfolio Metrics 2014 Generation 5,794GWh Capacity 2,532MW (1) Facilities Overview 1 2 3 31% 46% 23% 43% 14% 43% (1) Athens Millennium Harquahala Capacity (MW) 1,080 360 1,092 COD June 2004 April 2001 September 2004 Facility Type Combined Cycle Combined Cycle Combined Cycle Equipment Siemens 501G Siemens 501G Siemens 501G Configuration 3-1 CT x 1 ST 1 CT x 1 ST 3-1 CT x 1 ST Heat Rate (Btu/kWh) 7,100 6,975 7,100 Athens Millennium Harquahala (1) Based on nominal capacity ratings Talen Energy Corporation 2015 9

Athens: An Optimization Opportunity Athens Highlights Efficient 7,100 heat rate CCGT facility of scale with 1,080 MW of capacity located in NYISO Zone F Proven operating track record all 3 units have had a 95% or greater reliability factor over the past 3 years - Substantial investments in safety and reliability position the plant well Substantial optimization opportunity - Implementation of strategies to fully optimize the units will result in materially higher margins - Significant upside from planned gas infrastructure developments and transmission line upgrades Entry into NYISO Substantial Opportunity to Increase Output 95% 95% 92% 88% 60% 60% 38% 50% 28% 2012 2013 2014 2016E + (1) Compelling Future Outlook Gas infrastructure improvements (Constitution, TGP, and AGT) will bring low cost Marcellus gas directly to the plant, reducing gas basis differentials enhancing energy margin and capacity factor Expected to benefit from the tightening reserve margin in the market from higher energy and capacity values due to NYISO capacity retirements Transmission improvements expected to reduce Zone F / Zone G congestion Capacity Factor Availability Factor (1) Assumes average historical availability factor and projected capacity factor from asset optimization Talen Energy Corporation 2015 10

Millennium: Highly Attractive CCGT in ISO-NE Millennium Highlights Efficient sub-7,000 heat rate CCGT plant with 360 MW of capacity located in ISO-NE Proven operating track record 97% or greater reliability factor over the past 3 years Plant node pricing substantially correlated to Mass Hub, reducing basis risk ISO-NE has adopted a number of constructive market reforms, including capacity performance incentives, improved day-ahead market modeling and the adoption of a sloped demand curve, which should drive long-term pricing to reflect new build costs Adding a well-positioned Asset in ISO-NE Historically Solid Availability and Output 89% 88% 90% 65% 58% 47% 2012 2013 2014 Strong Market Fundamentals & Outlook Favorable supply and demand dynamics, including the retirement of aging plants, phase out of nuclear generation and no significant construction in progress have resulted in tight capacity markets and a marked shift in pricing Tennessee and Algonquin gas transmission pipelines expected to bring low-cost Marcellus gas to Massachusetts beginning in 2016, with incremental improvements scheduled through 2018 Capacity Factor Availability Factor Talen Energy Corporation 2015 11

Harquahala: Multiple Paths to Value Harquahala Highlights Efficient 7,100 heat rate CCGT plant in southwestern Arizona with 1,092 MW of capacity Adequate water supply provides competitive advantage Current market dynamics have limited the operational capability of a high quality plant - Sub-20% capacity factors despite very strong performance at a 99% or greater reliability factor over the past 3 years - Produces negative EBITDA and FCF Well-positioned to capture value as Desert Southwest faced with 111(d) compliance Location Limits Market Opportunity Potential partial or full sale to local load serving entity Multiple Opportunities to Deliver Value Achieve fleet wide Long-term Service Agreement (LTSA) savings across Talen Energy's nine 501G units New transmission access into California-ISO under development Move and relocate plant to another site $50 million to >$150 million Monetize station for parts value Talen Energy Corporation 2015 12

Financial Considerations Talen Energy Corporation 2015 13

Compelling Value ($ millions) Purchase Price $1,175 Less Inventory Value (13) Net Purchase Price 1,162 2016 EV / EBITDA ($120) 9.7x Implied $ / kw 459 Implied $ / k W, excluding Harquahala 807 Tax Attribute Value Net Purchase Price $1,162 Less NPV of Tax Attributes (245) Adjusted Purchase Price 917 2016 EV / EBITDA ($120) 7.6x Implied $ / kw 362 Implied $ / k W, excluding Harquahala 637 Harquahala Monetized Adjusted Purchase Price $917 Less Monetization of Harquahala (50) (150) Net Price for Athens and Millennium 867 767 2016 EV / EBITDA, excluding Harquahala ($130) 6.7x 5.9x Implied $ / k W, excluding Harquahala 602 533 A B C Nominal purchase price of $1,162 million net of inventory implies an EV / 2016 EBITDA multiple of 9.7x Deducting the PV of tax attributes reduces the asset purchase price to $917 million which is 7.6x 2016E EBITDA Monetizing Harquahala and removing its negative EBITDA contribution results in multiples in the low-to-mid 6.0x EV / 2016 EBITDA range Tax attributes and Harquahala offer significant value, driving the purchase price to a considerable discount to market multiples Peer Trading Multiples 2016 2017 Calpine 8.8x 8.6x Dynegy 7.5x 7.6x NRG 8.7x 9.2x Notes: Market data as of July 17, 2015. Peer multiples based upon EBITDA per FactSet consensus estimates. Implied $ / kw based on nominal capacity ratings Talen Energy Corporation 2015 14

2016 EBITDA & FCF Projections ($ in millions) Pre-Transaction Post-Transaction EBITDA: 2016E Adjusted EBITDA $885 $1,005 (1) 2016E Adjusted EBITDA, including special items $840 $960 Free Cash Flow: (2) 2016E Adjusted Free Cash Flow $290 $320 (1) (2) 2016E Adjusted Free Cash Flow, including special items $263 $293 (3) Projected Net Debt Outstanding at 12/31/2015 $3,700 $4,875 Projected Net Debt / 2016E Adjusted EBITDA 4.2x 4.9x Notes: Assumes transaction close by 12/31/2015. Does not reflect sale of approximately 1.3 GW of generating capacity that is required to comply with FERC order approving Talen Energy transaction. Refer to Supplemental Information Regulation G Reconciliations for reconciliation of non-gaap financial measures (1) Special items include Transition Service Agreements from Talen Energy transaction and restructuring costs (2) Does not include growth capex of $85 million (3) Includes projection of $170 million in short-term debt outstanding Talen Energy Corporation 2015 15

Transaction Financing Committed Acquisition Facility Permanent Financing Plan Purchase price backed by committed acquisition facility - Sized to accommodate full purchase price should MACH Gen debt not remain in place Total $1.175 billion purchase price to be financed with debt MACH Gen debt may be retained provided waiver on change of control achieved - Expected balance of approximately $565 million at time of closing - Cash required at closing dependent upon MACH Gen debt balance Will consider secured and/or unsecured debt - Final financing plan will take into consideration market conditions, amount of the existing MACH Gen debt to be retained as well as expected proceeds from FERC mitigation sales and other pending divestitures - May approach market ahead of closing Strategic and Prudent Use of Balance Sheet Talen Energy Corporation 2015 16

Regulatory Approvals and Expected Timeline Principal Required Approvals Required Approval Expected Timing Federal Energy Regulatory Commission (FERC) 3-4 months NY Public Service Commission 3-4 months (1) Hart-Scott-Rodino Federal Trade Commission (FTC) / Department of Justice (DOJ) 1-2 months (1) An additional 3-4 months could be added for certain supplementary filings if change of control waiver is not obtained from MACH Gen s lender and facility is pledged in support of acquisition financing Talen Energy Corporation 2015 17

Closing Remarks Talen Energy Corporation 2015 18

Executing Talen Energy s Strategy Strategic Priorities Communicated at Spin 50 Days Ago: MACH Gen: 1 2 3 4 5 Grow asset base in accretive manner Extend track record of originating transactions Expand presence in attractive markets Further diversify fuel mix Take advantage of cash taxpayer status Talen Energy Corporation 2015 19

Supplemental Information Talen Energy Corporation 2015 20

Transaction Terms and Timing Transaction & Purchase Price On July 18, 2015, Talen Energy Supply, LLC entered into an agreement to acquire MACH (1) Gen, LLC for $1.175 billion including value of existing debt assumed Financing Plan Citi has provided committed debt financing sufficient to fund the purchase price Considering retaining Mach Gen's existing term loan in combination with new secured or unsecured debt issued at Talen Energy Supply, LLC The final financing plan will take into consideration market conditions and the amount of existing MACH Gen debt to be retained, as well as expected proceeds from FERC mitigation sales and other pending divestitures Regulatory Approvals Federal: FERC and antitrust clearance under Hart-Scott-Rodino State: New York Public Service Commission Timing Expected to close by end of 2015 (1) Includes $13 million of inventory Talen Energy Corporation 2015 21

MACH Gen Asset Overview Athens Millennium Harquahala Location Nominal Capacity Athens, NY 1,080 MW COD June 2004 Heat Rate Market Trading Hub Capacity Primary Fuel Gas Interconnection Facility Type Configuration Key Equipment Site 7,100 Btu/kWh NYISO NYISO Zone F NYISO Rest-of-State Natural Gas Iroquois Gas Combined-Cycle 3 1 CT x 1 ST 3 Siemens 501G CTs 3 Nooter Eriksen HRSGs 3 Siemens STs 42-acre parcel Location Nominal Capacity Charlton, MA 360 MW COD April 2001 Heat Rate Market Trading Hub Capacity Primary Fuel Gas Interconnection Facility Type 6,975 Btu/kWh ISO-NE Mass Hub ISO-NE Rest-of-Pool Natural Gas (1) (1) Configuration Key Equipment Site Tennessee Gas Combined-Cycle 1 CT x 1 ST 1 Siemens 501G CTs 1 Nooter Eriksen HRSGs 1 Siemens STs 13-acre parcel Location Nominal Capacity Tonopah, AZ 1,092 MW COD September 2004 Heat Rate Market Trading Hub Fuel Gas Interconnection Facility Type Configuration Key Equipment Site Water Supply 7,100 Btu/kWh AZ-NM-SNV Palo Verde Natural Gas El Paso Combined-Cycle 3 1 CT x 1 ST 3 Siemens 501G CTs 3 NEM HRSGs 3 Siemens STs 640 acres Five on-site wells Existing delivery agreements with CAWCD / HVID Reliability and Availability Factors Reliability and Availability Factors Reliability and Availability Factors 99.5% 98.9% 98.0% 94.6% 94.6% 87.8% 99.6% 99.0% 98.4% 88.9% 88.2% 90.3% 99.7% 99.1% 99.9% 96.8% 93.5% 95.5% 2012 2013 2014 Reliability Factor Availability Factor 2012 2013 2014 Reliability Factor Availability Factor 2012 2013 2014 Reliability Factor Availability Factor (1) Fuel oil capable Talen Energy Corporation 2015 22

Regulation G Reconciliations Adjusted EBITDA ($ in Millions) Pre-Transaction Midpoint 2016E Transaction Adjustments Post-Transaction Midpoint 2016E Net Income/(Loss) $105 $2 $107 Income Taxes 56 1 57 Interest Expense 209 81 290 Depreciation & Amortization 422 36 458 EBITDA 792 120 912 Non-Cash Compensation 21 21 ARO 37 37 MTM losses (gains) NDT losses (gains) (10) (10) Adjusted EBITDA, including special items 840 120 960 Special items: TSA costs and allocations 45 45 Adjusted EBITDA $885 $120 $1,005 Talen Energy Corporation 2015 23

Regulation G Reconciliations Adjusted Free Cash Flow ($ in Millions) Pre-Transaction Midpoint 2016E Transaction Adjustments Post-Transaction Midpoint 2016E Cash from Operations $727 $55 $782 Sustenance Capital Expenditures (464) (25) (489) Adjusted Free Cash Flow, including special items 263 30 293 Special items: TSA costs & allocations (after tax) 27 27 Adjusted Free Cash Flow $290 $30 $320 Talen Energy Corporation 2015 24

Forward-Looking Information Statement Statements contained in this presentation, including statements with respect to future earnings, EBITDA results, cash flows, tax attributes, financing, regulation and corporate strategy are "forward-looking statements" within the meaning of the federal securities laws. Although Talen Energy Corporation believes that the expectations and assumptions reflected in these forward-looking statements are reasonable, these statements are subject to a number of risks and uncertainties, and actual results may differ materially from the results discussed in the statements. Among the important factors that could cause actual results to differ materially from the forward-looking statements are: market demand and prices for energy, capacity and fuel; weather conditions affecting customer energy usage and operating costs; competition in power markets; the effect of any business or industry restructuring; the profitability and liquidity of Talen Energy Corporation and its subsidiaries; new accounting requirements or new interpretations or applications of existing requirements; operating performance of generating plants and other facilities; unforeseen difficulties in successfully integrating the MACH Gen power facilities into Talen Energy's portfolio and/or in successfully executing efforts to optimize the value of the Harquahala plant; unexpected costs or liabilities associated with the MACH Gen power facilities; the length of scheduled and unscheduled outages at our generating plants; environmental conditions and requirements and the related costs of compliance, including environmental capital expenditures and emission allowance and other expenses; system conditions and operating costs; development of new projects, markets and technologies; performance of new ventures; asset or business acquisitions and dispositions; receipt of necessary governmental permits or approvals; capital market conditions and decisions regarding capital structure; the impact of state, federal or foreign investigations applicable to Talen Energy Corporation and its subsidiaries; the outcome of litigation against Talen Energy Corporation and its subsidiaries; stock price performance; the market prices of equity securities and the impact on pension income and resultant cash funding requirements for defined benefit pension plans; the securities and credit ratings of Talen Energy Corporation and its subsidiaries; political, regulatory or economic conditions in states, regions or countries where Talen Energy Corporation or its subsidiaries conduct business, including any potential effects of threatened or actual terrorism or war or other hostilities; foreign exchange rates; new state, federal or foreign legislation, including new tax legislation; changes in earnings estimates or buy/sell recommendations by analysts; volatility in market demand and prices for energy, capacity, transmission services, emission allowances and RECs; competition in retail and wholesale power and natural gas markets; and the commitments and liabilities of Talen Energy Corporation and its subsidiaries. Any such forward-looking statements should be considered in light of such important factors and in conjunction with Talen Energy Corporation's Registration Statement on Form S-1 and its other reports on file with the Securities and Exchange Commission. Talen Energy Corporation 2015 25

Definitions of Non-GAAP Financial Measures In this presentation the company presents EBITDA, Adjusted EBITDA and Adjusted EBITDA, including special items, each of which are non-gaap financial measures. EBITDA represents net income (loss) before interest expense, income taxes, depreciation and amortization. Adjusted EBITDA represents EBITDA adjusted for certain items as detailed in the reconciliation. Adjusted EBITDA, including special items, is Adjusted EBITDA prior to adjustment for items management considers special including TSA costs, pre-spin PPL charges and restructuring costs. EBITDA, Adjusted EBITDA and Adjusted EBITDA, including special items, are not intended to represent cash flows from operations or net income (loss) as defined by U.S. GAAP as indicators of operating performance and are not necessarily comparable to similarly-titled measures reported by other companies. We believe EBITDA, Adjusted EBITDA and Adjusted EBITDA, including special items, are useful to investors and other users of our financial statements in evaluating our operating performance because they provide additional tools to compare business performance across companies and across periods. We believe that EBITDA is widely used by investors to measure a company s operating performance without regard to such items as interest expense, income taxes, depreciation and amortization, which can vary substantially from company to company depending upon accounting methods and book value of assets, capital structure and the method by which assets were acquired. Additionally, we believe that investors commonly adjust EBITDA information to eliminate the effect of restructuring and other expenses, which vary widely from company to company and impair comparability. We adjust for these and other items as our management believes that these items would distort their ability to efficiently view and assess our core operating trends. In summary, our management uses EBITDA, Adjusted EBITDA and Adjusted EBITDA, including special items, as measures of operating performance to assist in comparing performance from period to period on a consistent basis and to readily view operating trends, as measures for planning and forecasting overall expectations and for evaluating actual results against such expectations, and in communications with our Board of Directors, shareholders, creditors, analysts and investors concerning our financial performance. Talen Energy Corporation 2015 26

Definitions of Non-GAAP Financial Measures Adjusted free cash flow is derived by deducting sustenance capital expenditures and after-tax special items from cash flow from operations, while adjusted free cash flow, including special items, is derived from adjusted free cash flow prior to adjustment for after-tax special items. These two non-gaap measures should not be considered alternatives to cash flow from operations, which is determined in accordance with GAAP. We believe that adjusted free cash flow and adjusted free cash flow, including special items, although both non-gaap measures, are important measures to both management and investors as indicators of the company s ability to sustain operations without additional outside financing beyond the requirement to fund maturing debt obligations. These measures are not necessarily comparable to similarly-titled measures reported by other companies as they may be calculated differently. Talen Energy Corporation 2015 27