| Segment Information |
Segment Information We assess our business on a regional basis due to the impact on our financial performance of the differing characteristics of these regions, particularly with respect to competition, regulation and other factors impacting supply and demand. During the third quarter of 2014, we altered the composition of our geographic segments to combine our former North and Southeast segments into one segment which was renamed the East segment. This change reflects the manner in which our geographic information is presented internally to our chief operating decision maker following the sale of six power plants in July 2014 that composed a substantial portion of our former Southeast segment. Thus, beginning in the third quarter of 2014, our reportable segments were West (including geothermal), Texas and East (including Canada). We continue to evaluate the manner in which we assess our performance, including our segments, which may result in future changes to the composition of our geographic segments. Commodity Margin is a key operational measure reviewed by our chief operating decision maker to assess the performance of our segments. The tables below show our financial data for our segments for the periods indicated (in millions). | | | | | | | | | | | | | | | | | | | | | | Three Months Ended June 30, 2015 | | West | | Texas | | East | | Consolidation and Elimination | | Total | Revenues from external customers | $ | 421 |
| | $ | 570 |
| | $ | 451 |
| | $ | — |
| | $ | 1,442 |
| Intersegment revenues | — |
| | 5 |
| | 2 |
| | (7 | ) | | — |
| Total operating revenues | $ | 421 |
| | $ | 575 |
| | $ | 453 |
| | $ | (7 | ) | | $ | 1,442 |
| Commodity Margin | $ | 240 |
| | $ | 170 |
| | $ | 247 |
| | $ | — |
| | $ | 657 |
| Add: Mark-to-market commodity activity, net and other(1) | (14 | ) | | 10 |
| | 30 |
| | (7 | ) | | 19 |
| Less: | | | | | | | | | | Plant operating expense | 120 |
| | 82 |
| | 77 |
| | (7 | ) | | 272 |
| Depreciation and amortization expense | 65 |
| | 50 |
| | 45 |
| | — |
| | 160 |
| Sales, general and other administrative expense | 6 |
| | 15 |
| | 9 |
| | — |
| | 30 |
| Other operating expenses | 10 |
| | 2 |
| | 8 |
| | — |
| | 20 |
| (Income) from unconsolidated investments in power plants | — |
| | — |
| | (7 | ) | | — |
| | (7 | ) | Income from operations | 25 |
| | 31 |
| | 145 |
| | — |
| | 201 |
| Interest expense, net of interest income | | | | | | | | | 157 |
| Debt modification costs and other (income) expense, net | | | | | | | | | 18 |
| Income before income taxes | | | | | | | | | $ | 26 |
|
| | | | | | | | | | | | | | | | | | | | | | Three Months Ended June 30, 2014 | | West | | Texas | | East | | Consolidation and Elimination | | Total | Revenues from external customers | $ | 487 |
| | $ | 960 |
| | $ | 492 |
| | $ | — |
| | $ | 1,939 |
| Intersegment revenues | 1 |
| | 3 |
| | 27 |
| | (31 | ) | | — |
| Total operating revenues | $ | 488 |
| | $ | 963 |
| | $ | 519 |
| | $ | (31 | ) | | $ | 1,939 |
| Commodity Margin(2) | $ | 228 |
| | $ | 177 |
| | $ | 227 |
| | $ | — |
| | $ | 632 |
| Add: Mark-to-market commodity activity, net and other(1) | 21 |
| | 184 |
| | (24 | ) | | (8 | ) | | 173 |
| Less: | | | | | | | | | | Plant operating expense | 95 |
| | 83 |
| | 103 |
| | (7 | ) | | 274 |
| Depreciation and amortization expense | 58 |
| | 48 |
| | 40 |
| | 1 |
| | 147 |
| Sales, general and other administrative expense | 7 |
| | 18 |
| | 12 |
| | 1 |
| | 38 |
| Other operating expenses | 15 |
| | 1 |
| | 9 |
| | (4 | ) | | 21 |
| (Income) from unconsolidated investments in power plants | — |
| | — |
| | (4 | ) | | — |
| | (4 | ) | Income from operations | 74 |
| | 211 |
| | 43 |
| | 1 |
| | 329 |
| Interest expense, net of interest income | | | | | | | | | 167 |
| Other (income) expense, net | | | | | | | | | 6 |
| Income before income taxes | | | | | | | | | $ | 156 |
|
| | | | | | | | | | | | | | | | | | | | | | Six Months Ended June 30, 2015 | | West | | Texas | | East | | Consolidation and Elimination | | Total | Revenues from external customers | $ | 936 |
| | $ | 1,151 |
| | $ | 1,001 |
| | $ | — |
| | $ | 3,088 |
| Intersegment revenues | 2 |
| | 8 |
| | 4 |
| | (14 | ) | | — |
| Total operating revenues | $ | 938 |
| | $ | 1,159 |
| | $ | 1,005 |
| | $ | (14 | ) | | $ | 3,088 |
| Commodity Margin | $ | 458 |
| | $ | 319 |
| | $ | 415 |
| | $ | — |
| | $ | 1,192 |
| Add: Mark-to-market commodity activity, net and other(3) | 105 |
| | 51 |
| | (22 | ) | | (14 | ) | | 120 |
| Less: | | | | | | | | | | Plant operating expense | 226 |
| | 171 |
| | 149 |
| | (14 | ) | | 532 |
| Depreciation and amortization expense | 132 |
| | 99 |
| | 87 |
| | — |
| | 318 |
| Sales, general and other administrative expense | 16 |
| | 32 |
| | 19 |
| | — |
| | 67 |
| Other operating expenses | 20 |
| | 4 |
| | 16 |
| | — |
| | 40 |
| (Income) from unconsolidated investments in power plants | — |
| | — |
| | (12 | ) | | — |
| | (12 | ) | Income from operations | 169 |
| | 64 |
| | 134 |
| | — |
| | 367 |
| Interest expense, net of interest income | | | | | | | | | 310 |
| Debt modification and extinguishment costs and other (income) expense, net | | | | | | | | | 39 |
| Income before income taxes | | | | | | | | | $ | 18 |
|
| | | | | | | | | | | | | | | | | | | | | | Six Months Ended June 30, 2014 | | West | | Texas | | East | | Consolidation and Elimination | | Total | Revenues from external customers | $ | 978 |
| | $ | 1,607 |
| | $ | 1,319 |
| | $ | — |
| | $ | 3,904 |
| Intersegment revenues | 3 |
| | 15 |
| | 44 |
| | (62 | ) | | — |
| Total operating revenues | $ | 981 |
| | $ | 1,622 |
| | $ | 1,363 |
| | $ | (62 | ) | | $ | 3,904 |
| Commodity Margin(2) | $ | 430 |
| | $ | 298 |
| | $ | 549 |
| | $ | — |
| | $ | 1,277 |
| Add: Mark-to-market commodity activity, net and other(3) | 50 |
| | 138 |
| | (35 | ) | | (17 | ) | | 136 |
| Less: | | | | | | | | | | Plant operating expense | 200 |
| | 173 |
| | 182 |
| | (16 | ) | | 539 |
| Depreciation and amortization expense | 118 |
| | 90 |
| | 91 |
| | 1 |
| | 300 |
| Sales, general and other administrative expense | 17 |
| | 30 |
| | 24 |
| | — |
| | 71 |
| Other operating expenses | 27 |
| | 3 |
| | 16 |
| | (3 | ) | | 43 |
| (Income) from unconsolidated investments in power plants | — |
| | — |
| | (13 | ) | | — |
| | (13 | ) | Income from operations | 118 |
|
| 140 |
|
| 214 |
|
| 1 |
| | 473 |
| Interest expense, net of interest income | | | | | | | | | 332 |
| Debt extinguishment costs and other (income) expense, net | | | | | | | | | 17 |
| Income before income taxes | | | | | | | | | $ | 124 |
|
_________ | | (1) | Includes $(18) million and $(27) million of lease levelization and $3 million and $3 million of amortization expense for the three months ended June 30, 2015 and 2014, respectively. |
| | (2) | Commodity Margin related to the six power plants sold in our East segment on July 3, 2014, was $42 million and $81 million for the three and six months ended June 30, 2014, respectively. |
| | (3) | Includes $(42) million and $(56) million of lease levelization and $7 million and $7 million of amortization expense for the six months ended June 30, 2015 and 2014, respectively. |
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