Type of Asset Useful Life. Land Unexpiredterms of the leases Cable tunnels 100 years Buildings 60 years Ash lagoon 60 years Gas pipeline 60 years Overhead lines 60 years Cables 60 years Transmission and distribution equipment 60 years Generating plant and machinery 35 years Gas turbines and gas turbine combined cycle 30 years Mechanical meters 30 years Wind turbines 20 years Electronic meters; microwave and optical fibre equipment and 15 years trunk radio system Furniture and fixture; sundry plant and equipment Engineering and general purpose computers Commercial motor vehicles and marine craft Personal computers; office equipment; workshop tools 10 years 10 years 6 years 5 years Motor vehicles 5 years Refurbished or improved assets Remaining original life plus any life extension.
Type of Asset Useful Life. Land ： Unexpired terms of the leases Buildings and civil structures at ： 35 years power stations Ash lagoon ： 35 years Other buildings and civil Generating plant (including ： ： 50 years 25 years natural gas pipeline) Overhead lines (33 kV and ： 50 years above) Overhead lines (below 33 kV) ： 45 years Cables (132kV and above) ： 55 years Cables (below 132kV) ： 60 years Cable tunnels ： 100 years structures Switchgear and transformers ： 50 years Substation miscellaneous ： 25 years Meters ： 15 years System control equipment, furniture, tools, communication and office equipment Computers and office automation equipment other than those forming an integral part of the generating plant : 10 years : 5 years Motor vehicles and marine craft : 5 years Refurbished or improved assets : Remaining original life plus any life extension.
Type of Asset Useful Life. Land : Unexpired terms of the leases Cable tunnels : 100 years Buildings : 35 years Generating plant : 25 years Overhead Lines(132 kV and above) : Overhead Lines(below 132 kV) : Cables : 35 years 30 years 30 years Switchgear and transformers : 35 years Meters : 15 years System control equipment, furniture, tools, communication and office equipment Computers and office automation equipment other than those forming an integral part of the generating plant : 10 years : 5 years Motor vehicles and marine craft : 5 years Refurbished or improved assets : Remaining original life plus any life extension. ”
