16. Other intangible assets - 77,730 thousand euros

These amounted to 77,730 thousand euros (115,067 thousand euros as at 31 December 2011), marking a decrease of 37,336 thousand euros and are broken down as follows.

€ thousand  31.12.2011 Change in basis of consolidation Investments/ Acquisitions
Patent rights 50,651 0 9,448
Other intangible assets 43,307 0 2,542
Fixed assets in progress 21,108 0 6,710
TOTAL 115,067 0 18,700
  Amortisation/depreciation Disposals and other movements 31.12.2012
Patent rights (26,257) 14,360 48,203
Other intangible assets (4,353) (17,724) 23,772
Fixed assets in progress 0 (22,062) 5,756
TOTAL (30,610) (25,426) 77,730

The decrease compared to last year was due to the net effect of investments for the period of 18,700 thousand euros, amortisation for 30,610 thousand euros and reclassifications for 25,426 thousand euros.

The investments made in the period refer to (i) ACEA Distribuzione for 5,123 thousand euros, (ii) Acea Energia for 7,299 thousand euros, (iii) Acea Energia Holding for 503 thousand euros and (iv) SAO for 200 thousand euros.

Intangible assets of ACEA Distribuzione include the costs incurred for the re-engineering project for information and commercial systems in the distribution area (13,255 thousand euros) and the standardisation of systems used in meter reading (3,213 thousand euros).

“Disposals and other movements” mainly refers to 12,075 thousand euros of green certificates revenue accrued by the hydroelectric power stations. Given that these are assets for instant use, they are not amortised but are tested for impairment. The recoverable amount is the higher of the asset’s value in use and its market value.