Transaction Impacts Assuming No Synergies and No Transaction Costs(1) 1 Notes: Assuming additional debt at 4.81% interest rate cost and 26.5% corporate tax rate as per Indiana management. Indiana TSO (Total Shares Outstanding) of 6,423MM based on public company numbers. Exchange rate of $1.083 per euro Assuming 72.6MM shares to be acquired at tender offer out of 388MM FDSO (Fully Diluted Shares Outstanding). Arizona FDSO compounds: 387MM of outstanding shares as of Q4-2023 (of which 315.7MM owned by Indiana), 1.5MM in PSUs (Phantom Shared Units) and RSUs (Restricted Stock Units) nonvested as of Dec 2023 and adjusted for 0.01MM in RSUs granted and settled in January 2024 Premium over current price of $31.1 p.s. as of 1 March 2024 Source: Capital IQ as of March 1, 2024, Credit Rating Reports and Company Information Indiana BBB+ Thresholds 17-18% 17.0% Indiana Standalone 20.7% 20.6% Accretion / (Dilution)(2) Acquisition Financing Moody´s FFO/ND S&P FFO/ND 2025 2025 Acquisition Debt Premium over Share Price(3) 2026 2025 Repowering Delay $38.0p.s. Offer Price 19.7% 19.5% $2.8Bn 22.1% 0.8% 0.9% $37.0p.s. Offer Price 19.7% 19.5% $2.7Bn 18.9% 0.8% 0.9% $35.0p.s. Offer Price 19.7% 19.6% $2.5Bn 12.4% 0.9% 1.0% No Repowering Delay $38.0p.s. Offer Price 19.7% 19.5% $2.8Bn 22.1% 0.5% 0.6% $37.0p.s. Offer Price 19.7% 19.5% $2.7Bn 18.9% 0.6% 0.6% $35.0p.s. Offer Price 19.7% 19.6% $2.5Bn 12.4% 0.7% 0.7% $36.0p.s. Offer Price 19.7% 19.5% $2.6Bn 15.6% 0.6% 0.7% $36.0p.s. Offer Price 19.7% 19.5% $2.6Bn 15.6% 0.9% 1.0% Exhibit (c)(12)