| Segment and Significant Customer Information |
| | | Segment and Significant Customer 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. At December 31, 2012, our reportable segments were West (including geothermal), Texas, North (including Canada) and Southeast. We continue to evaluate the optimal manner in which we assess our performance including our segments and future changes may result. 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). | | | | | | | | | | | | | | | | | | | | | | | | | | Year Ended December 31, 2012 | | West | | Texas | | North | | Southeast | | Consolidation and Elimination | | Total | Revenues from external customers | $ | 1,668 |
| | $ | 1,857 |
| | $ | 1,280 |
| | $ | 673 |
| | $ | — |
| | $ | 5,478 |
| Intersegment revenues | 10 |
| | 61 |
| | 14 |
| | 80 |
| | (165 | ) | | — |
| Total operating revenues | $ | 1,678 |
| | $ | 1,918 |
| | $ | 1,294 |
| | $ | 753 |
| | $ | (165 | ) | | $ | 5,478 |
| Commodity Margin (1)(2) | $ | 994 |
| | $ | 570 |
| | $ | 729 |
| | $ | 245 |
| | $ | — |
| | $ | 2,538 |
| Add: Unrealized mark-to-market commodity activity, net and other(3) | (93 | ) | | 87 |
| | (14 | ) | | (33 | ) | | (31 | ) | | (84 | ) | Less: | | | | | | | | | | | | Plant operating expense | 368 |
| | 247 |
| | 206 |
| | 131 |
| | (30 | ) | | 922 |
| Depreciation and amortization expense | 203 |
| | 142 |
| | 134 |
| | 85 |
| | (2 | ) | | 562 |
| Sales, general and other administrative expense | 36 |
| | 47 |
| | 28 |
| | 29 |
| | — |
| | 140 |
| Other operating expenses | 42 |
| | 5 |
| | 29 |
| | 5 |
| | (3 | ) | | 78 |
| (Gain) on sale of assets, net | — |
| | — |
| | (7 | ) | | (215 | ) | | — |
| | (222 | ) | (Income) from unconsolidated investments in power plants | — |
| | — |
| | (28 | ) | | — |
| | — |
| | (28 | ) | Income from operations | 252 |
| | 216 |
| | 353 |
| | 177 |
| | 4 |
| | 1,002 |
| Interest expense, net of interest income | | | | | | | | | | | 725 |
| Loss on interest rate derivatives | | | | | | | | | | | 14 |
| Debt extinguishment costs and other (income) expense, net | | | | | | | | | | | 45 |
| Income before income taxes and discontinued operations | | | | | | | | | | | $ | 218 |
|
| | | | | | | | | | | | | | | | | | | | | | | | | | Year Ended December 31, 2011 | | West | | Texas | | North | | Southeast | | Consolidation and Elimination | | Total | Revenues from external customers | $ | 2,372 |
| | $ | 2,306 |
| | $ | 1,336 |
| | $ | 786 |
| | $ | — |
| | $ | 6,800 |
| Intersegment revenues | 12 |
| | 23 |
| | 7 |
| | 135 |
| | (177 | ) | | — |
| Total operating revenues | $ | 2,384 |
| | $ | 2,329 |
| | $ | 1,343 |
| | $ | 921 |
| | $ | (177 | ) | | $ | 6,800 |
| Commodity Margin(1)(2) | $ | 1,061 |
| | $ | 469 |
| | $ | 704 |
| | $ | 240 |
| | $ | — |
| | $ | 2,474 |
| Add: Unrealized mark-to-market commodity activity, net and other(3) | 113 |
| | (102 | ) | | (13 | ) | | 1 |
| | (32 | ) | | (33 | ) | Less: | | | | | | | | | | | | Plant operating expense | 380 |
| | 235 |
| | 177 |
| | 141 |
| | (29 | ) | | 904 |
| Depreciation and amortization expense | 192 |
| | 135 |
| | 138 |
| | 90 |
| | (5 | ) | | 550 |
| Sales, general and other administrative expense | 43 |
| | 43 |
| | 24 |
| | 22 |
| | (1 | ) | | 131 |
| Other operating expenses | 41 |
| | 3 |
| | 30 |
| | 5 |
| | (2 | ) | | 77 |
| (Income) from unconsolidated investments in power plants | — |
| | — |
| | (21 | ) | | — |
| | — |
| | (21 | ) | Income (loss) from operations | 518 |
| | (49 | ) | | 343 |
| | (17 | ) | | 5 |
| | 800 |
| Interest expense, net of interest income | | | | | | | | | | | 751 |
| Loss on interest rate derivatives | | | | | | | | | | | 145 |
| Debt extinguishment costs and other (income) expense, net | | | | | | | | | | | 115 |
| Loss before income taxes and discontinued operations | | | | | | | | | | | $ | (211 | ) |
| | | | | | | | | | | | | | | | | | | | | | | | | | Year Ended December 31, 2010 | | West | | Texas | | North | | Southeast | | Consolidation and Elimination | | Total | Revenues from external customers | $ | 2,525 |
| | $ | 2,162 |
| | $ | 978 |
| | $ | 880 |
| | $ | — |
| | $ | 6,545 |
| Intersegment revenues | 12 |
| | 22 |
| | 6 |
| | 138 |
| | (178 | ) | | — |
| Total operating revenues | $ | 2,537 |
| | $ | 2,184 |
| | $ | 984 |
| | $ | 1,018 |
| | $ | (178 | ) | | $ | 6,545 |
| Commodity Margin(1)(2) | $ | 1,080 |
| | $ | 504 |
| | $ | 535 |
| | $ | 272 |
| | $ | — |
| | $ | 2,391 |
| Add: Unrealized mark-to-market commodity activity, net and other | 69 |
| | 89 |
| | 21 |
| | 22 |
| | (30 | ) | | 171 |
| Less: | | | | | | | | | | | | Plant operating expense | 351 |
| | 285 |
| | 138 |
| | 123 |
| | (29 | ) | | 868 |
| Depreciation and amortization expense | 207 |
| | 150 |
| | 111 |
| | 109 |
| | (7 | ) | | 570 |
| Sales, general and other administrative expense | 55 |
| | 38 |
| | 45 |
| | 12 |
| | 1 |
| | 151 |
| Other operating expenses | 59 |
| | 2 |
| | 28 |
| | 4 |
| | (2 | ) | | 91 |
| Impairment losses | 97 |
| | — |
| | — |
| | 19 |
| | — |
| | 116 |
| (Gain) on sale of assets, net | — |
| | (119 | ) | | — |
| | — |
| | — |
| | (119 | ) | (Income) from unconsolidated investments in power plants | — |
| | — |
| | (16 | ) | | — |
| | — |
| | (16 | ) | Income from operations | 380 |
| | 237 |
| | 250 |
| | 27 |
| | 7 |
| | 901 |
| Interest expense, net of interest income | | | | | | | | | | | 802 |
| Loss on interest rate derivatives | | | | | | | | | | | 223 |
| Debt extinguishment costs and other (income) expense, net | | | | | | | | | | | 106 |
| Loss before income taxes and discontinued operations | | | | | | | | | | | $ | (230 | ) |
__________ | | (1) | Our North segment includes Commodity Margin related to Riverside Energy Center, LLC of $73 million , $70 million and $73 million for the years ended December 31, 2012, 2011 and 2010, respectively. |
| | (2) | Our Southeast segment includes Commodity Margin related to Broad River of $52 million, $51 million and $55 million for the years ended December 31, 2012, 2011 and 2010, respectively. |
| | (3) | Includes $1 million and $12 million of lease levelization and $14 million and $8 million of amortization expense for the years ended December 31, 2012 and 2011, respectively, related to contracts that became effective in 2011. |
Significant Customer For the years ended December 31, 2012 and 2011, we had one significant customer, PJM Settlement, Inc., that accounted for more than 10% of our annual consolidated revenues. Our revenues of $713 million and $742 million from PJM Settlement, Inc. for the years ended December 31, 2012 and 2011, respectively, were attributed to our North segment. Our receivables from PJM Settlement, Inc. were $37 million and $28 million as of December 31, 2012 and 2011, respectively. We did not have a customer that accounted for more than 10% of our annual consolidated revenues for the year ended December 31, 2010. |