| 2013 | 2012 | |
|---|---|---|
| Depreciation of tangible assets | 50,505 | 48,751 |
| Impairment of tangible assets | 162,178 | 13,171 |
| Amortisation of intangible assets | 3,700 | 3,455 |
| Impairment of intangible assets | 7,855 | - |
| Total | 224,238 | 65,377 |
Impairments of tangible and intangible assets are explained in Notes 7 and 8. Impairments of advance payments, certificates of origin and prepaid long-term electricity procurement agreements are recognised under energy procurement (Note 10).