**Rounding Conventions**. • Regarding rounding of TSRs, percentages for each company in the Peer Group shall be computed to two decimal points (i.e., XX.XX%). • Regarding TSR Percentile Rank, the percentile rankings for each company in the Peer Group shall be rounded to the nearest percentage (e.g., 85% rather than 85.4166666%) before calculating the linearly interpolated payout, and the final payout percentage shall be rounded to the nearest percentage (e.g., 183% rather than 183.333333%). • Target Units that will vest and any Additional Shares that will be issued from the application of the methods and formula set forth in the foregoing subsection F(3) and Section D above shall only be paid out in whole shares of Common Stock. Any fractional shares that would otherwise result from such application shall be rounded down to the nearest whole number of shares.

**Rounding Conventions**. Regarding rounding of results, percentages shall be computed to one decimal point (i.e., XX.X%). • Target Units that will vest and any Additional Shares that will be issued from the application of the methods in the foregoing subsection F(3) and Section D above shall only be paid out in whole shares of Common Stock. Any fractional shares that would otherwise result from such application shall be rounded down to the nearest whole number of shares.

**Rounding Conventions**. For purposes of calculating any Share amounts pursuant to the foregoing formulae, the applicable number of Shares shall be rounded to the nearest whole number. EXHIBIT A SECTION 83(B) TAX ELECTION

**Rounding Conventions**. Regarding rounding of TSRs, percentages for each company in the Peer Group shall be computed to two decimal points, i.e., XX.XX%) • Regarding TSR Percentile Rank, the percentile rankings for each company in the Peer Group shall be rounded to the nearest percentage (e.g., 85% rather than 85.4166666%) before calculating the linearly interpolated payout, and the final payout percentage shall be rounded to the nearest percentage (e.g., 183% rather than 183.333333%). • Target Shares that will vest and any Additional Shares that will result from the application of the methods and formula set forth in the foregoing subsection F (3) and Section D above shall only be paid out in whole shares. Any fractional shares that would otherwise result from such application shall be rounded down to the nearest whole number of shares. EXHIBIT B Vesting Schedule Based on Operational Metric for Fifty Percent (50%) of RSUs Granted under Award Agreement

**Rounding Conventions**. Regarding rounding of TSRs, percentages for each company in the Peer Group shall be computed to two decimal points (i.e., XX.XX%). • Regarding TSR Percentile Rank, the percentile rankings for each company in the Peer Group shall be rounded to the nearest percentage (e.g., 85% rather than 85.4166666%) before calculating the linearly interpolated payout, and the final payout percentage shall be rounded to the nearest percentage (e.g., 183% rather than 183.333333%). • Target Units that will vest and any Additional Shares that will result from the application of the methods and formula set forth in the foregoing subsection F(3) and Section D above shall only be paid out in whole shares of Common Stock. Any fractional shares that would otherwise result from such application shall be rounded down to the nearest whole number of shares. Exhibit B (California Employees) If Participant resides in the State of California, Section 15(c)(ii) of the foregoing Performance Share Unit Award Agreement shall be restated as follows:

**Rounding Conventions**. Regarding rounding of results, percentages shall be computed to one decimal point (i.e., XX.X%). • Target Units that will vest and any Additional Shares that will be issued result from the application of the methods in the foregoing subsection F(3) and Section D above shall only be paid out in whole shares of Common Stock. Any fractional shares that would otherwise result from such application shall be rounded down to the nearest whole number of shares. Exhibit B (California Employees) If Participant resides in the State of California, Section 15(c)(ii) of the foregoing Performance Share Unit Award Agreement shall be restated as follows:

**Rounding Conventions**. The Corporation may, in its sole discretion and taking into account any requirements of the Code, determine the effect of any adjustments on Shares and may provide that no fractional Shares will be issued (rounding up or down as determined by the Corporation).

**Rounding Conventions**. The following conventions will apply for values used and values computed for this procedure: • Heat Rate – MMBtu/MWh rounded to 3 decimal places • NOx emission rate – pounds/MMBtu rounded to 3 decimal places • Tons of NOx emissions – tons rounded to 0 decimal places • Value of NOx emission allowances – dollars rounded to 0 decimal places • MWh dispatched – MWh rounded to 3 decimal places

**Rounding Conventions**. Regarding rounding of TSRs, percentages for each company in the Peer Group shall be computed to two decimal points, i.e., XX.XX%) • Regarding TSR Percentile Rank, the percentile rankings for each company in the Peer Group shall be rounded to the nearest percentage (e.g., 85% rather than 85.4166666%) before calculating the linearly interpolated payout, and the final payout percentage shall be rounded to the nearest percentage (e.g., 183% rather than 183.333333%).