| Year ended 31 December | Notes | 2019 £m |
2018 £m |
|---|---|---|---|
| Revenue | 5 | 1,579 | 1,854 |
| Cost of sales | 6 | (1,192) | (1,226) |
| Re-measurement of energy contracts | 7 | 194 | (5) |
| Gross profit | 581 | 623 | |
| Operating costs | 6 | (180) | (202) |
| Exceptional items | 7 | (516) | 91 |
| Operating (loss)/profit | (115) | 512 | |
| Financing costs | 8 | (46) | (42) |
| Investment income | 8 | 5 | 15 |
| (Loss)/profit before taxation | (156) | 485 | |
| Taxation on (loss)/profit | 9 | (115) | (294) |
| (Loss)/profit for the year | (271) | 191 |