| Schedule of Financial Data for Segments |
The tables below show our financial data for our segments for the periods indicated (in millions). | | | | | | | | | | | | | | | | | | | | | | Three Months Ended September 30, 2016 | | West | | Texas | | East | | Consolidation and Elimination | | Total | Revenues from external customers | $ | 524 |
| | $ | 1,067 |
| | $ | 764 |
| | $ | — |
| | $ | 2,355 |
| Intersegment revenues | 1 |
| | 3 |
| | 2 |
| | (6 | ) | | — |
| Total operating revenues | $ | 525 |
| | $ | 1,070 |
| | $ | 766 |
| | $ | (6 | ) | | $ | 2,355 |
| Commodity Margin | $ | 298 |
| | $ | 198 |
| | $ | 324 |
| | $ | — |
| | $ | 820 |
| Add: Mark-to-market commodity activity, net and other(1) | 11 |
| | 110 |
| | (51 | ) | | (7 | ) | | 63 |
| Less: | | | | | | | | | | Plant operating expense | 79 |
| | 65 |
| | 78 |
| | (7 | ) | | 215 |
| Depreciation and amortization expense | 56 |
| | 53 |
| | 52 |
| | — |
| | 161 |
| Sales, general and other administrative expense | 9 |
| | 13 |
| | 12 |
| | (1 | ) | | 33 |
| Other operating expenses | 8 |
| | 2 |
| | 7 |
| | 1 |
| | 18 |
| (Income) from unconsolidated investments in power plants | — |
| | — |
| | (6 | ) | | — |
| | (6 | ) | Income from operations | 157 |
| | 175 |
| | 130 |
| | — |
| | 462 |
| Interest expense, net of interest income | | | | | | | | | 157 |
| Other (income) expense, net | | | | | | | | | 8 |
| Income before income taxes | | | | | | | | | $ | 297 |
|
| | | | | | | | | | | | | | | | | | | | | | Three Months Ended September 30, 2015 | | West | | Texas | | East | | Consolidation and Elimination | | Total | Revenues from external customers | $ | 736 |
| | $ | 709 |
| | $ | 503 |
| | $ | — |
| | $ | 1,948 |
| Intersegment revenues | 1 |
| | 4 |
| | 3 |
| | (8 | ) | | — |
| Total operating revenues | $ | 737 |
| | $ | 713 |
| | $ | 506 |
| | $ | (8 | ) | | $ | 1,948 |
| Commodity Margin | $ | 385 |
| | $ | 264 |
| | $ | 325 |
| | $ | — |
| | $ | 974 |
| Add: Mark-to-market commodity activity, net and other(1) | 68 |
| | (98 | ) | | (62 | ) | | (7 | ) | | (99 | ) | Less: | | | | | | | | | | Plant operating expense | 87 |
| | 62 |
| | 57 |
| | (6 | ) | | 200 |
| Depreciation and amortization expense | 61 |
| | 58 |
| | 48 |
| | (1 | ) | | 166 |
| Sales, general and other administrative expense | 7 |
| | 15 |
| | 10 |
| | 1 |
| | 33 |
| Other operating expenses | 8 |
| | 2 |
| | 8 |
| | (2 | ) | | 16 |
| (Income) from unconsolidated investments in power plants | — |
| | — |
| | (6 | ) | | — |
| | (6 | ) | Income from operations | 290 |
| | 29 |
| | 146 |
| | 1 |
| | 466 |
| Interest expense, net of interest income | | | | | | | | | 158 |
| Other (income) expense, net | | | | | | | | | 1 |
| Income before income taxes | | | | | | | | | $ | 307 |
|
| | | | | | | | | | | | | | | | | | | | | | Nine Months Ended September 30, 2016 | | West | | Texas | | East | | Consolidation and Elimination | | Total | Revenues from external customers | $ | 1,159 |
| | $ | 2,129 |
| | $ | 1,846 |
| | $ | — |
| | $ | 5,134 |
| Intersegment revenues | 4 |
| | 10 |
| | 9 |
| | (23 | ) | | — |
| Total operating revenues | $ | 1,163 |
| | $ | 2,139 |
| | $ | 1,855 |
| | $ | (23 | ) | | $ | 5,134 |
| Commodity Margin | $ | 749 |
| | $ | 511 |
| | $ | 797 |
| | $ | — |
| | $ | 2,057 |
| Add: Mark-to-market commodity activity, net and other(2) | (5 | ) | | 7 |
| | (44 | ) | | (21 | ) | | (63 | ) | Less: | | | | | | | | | | Plant operating expense | 268 |
| | 236 |
| | 258 |
| | (21 | ) | | 741 |
| Depreciation and amortization expense | 181 |
| | 159 |
| | 163 |
| | — |
| | 503 |
| Sales, general and other administrative expense | 27 |
| | 43 |
| | 36 |
| | — |
| | 106 |
| Other operating expenses | 23 |
| | 6 |
| | 27 |
| | (1 | ) | | 55 |
| (Income) from unconsolidated investments in power plants | — |
| | — |
| | (16 | ) | | — |
| | (16 | ) | Income from operations | 245 |
| | 74 |
| | 285 |
| | 1 |
| | 605 |
| Interest expense, net of interest income | | | | | | | | | 469 |
| Debt extinguishment costs and other (income) expense, net | | | | | | | | | 36 |
| Income before income taxes | | | | | | | | | $ | 100 |
|
| | | | | | | | | | | | | | | | | | | | | | Nine Months Ended September 30, 2015 | | West | | Texas | | East | | Consolidation and Elimination | | Total | Revenues from external customers | $ | 1,672 |
| | $ | 1,860 |
| | $ | 1,504 |
| | $ | — |
| | $ | 5,036 |
| Intersegment revenues | 3 |
| | 12 |
| | 7 |
| | (22 | ) | | — |
| Total operating revenues | $ | 1,675 |
| | $ | 1,872 |
| | $ | 1,511 |
| | $ | (22 | ) | | $ | 5,036 |
| Commodity Margin | $ | 843 |
| | $ | 583 |
| | $ | 740 |
| | $ | — |
| | $ | 2,166 |
| Add: Mark-to-market commodity activity, net and other(2) | 173 |
| | (47 | ) | | (84 | ) | | (21 | ) | | 21 |
| Less: | | | | | | | | | | Plant operating expense | 313 |
| | 233 |
| | 206 |
| | (20 | ) | | 732 |
| Depreciation and amortization expense | 193 |
| | 157 |
| | 135 |
| | (1 | ) | | 484 |
| Sales, general and other administrative expense | 23 |
| | 47 |
| | 29 |
| | 1 |
| | 100 |
| Other operating expenses | 28 |
| | 6 |
| | 24 |
| | (2 | ) | | 56 |
| (Income) from unconsolidated investments in power plants | — |
| | — |
| | (18 | ) | | — |
| | (18 | ) | Income from operations | 459 |
|
| 93 |
|
| 280 |
|
| 1 |
| | 833 |
| Interest expense, net of interest income | | | | | | | | | 468 |
| Debt modification and extinguishment costs and other (income) expense, net | | | | | | | | | 40 |
| Income before income taxes | | | | | | | | | $ | 325 |
|
_________ | | (1) | Includes $40 million and $41 million of lease levelization and $25 million and $4 million of amortization expense for the three months ended September 30, 2016 and 2015, respectively. |
| | (2) | Includes $(2) million and $(1) million of lease levelization and $79 million and $11 million of amortization expense for the nine months ended September 30, 2016 and 2015, respectively. |
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