Coleridge Power Station

The Coleridge Power Station is a hydroelectric facility at Lake Coleridge on the Rakaia River in Canterbury, New Zealand. The power station is owned and operated by TrustPower. As of 2012, the station generates 39 megawatts (52,000 hp) of electricity, and annual generation averages 270 gigawatt-hours (970 TJ), following redesign of the station's turbines using Computational Fluid Dynamic modelling.[1]

Coleridge Power Station
Horizontal turbine (BTH) at Lake Coleridge power station
Country	New Zealand
Location	Canterbury
Coordinates	43°21′51″S 171°31′37″E
Status	Operational
Commission date	1914
Owner(s)	TrustPower
Turbine technology	Hydroelectric
Power generation
Units operational	3 (1914), 7 (1930), 3 (present)
Nameplate capacity	39 MW (52,000 hp) (1914: 4.5 MW (6,000 hp), 1930: 34.5 MW (46,300 hp))

Coleridge was the first major power station in which the state was involved. It was constructed mainly to supply electricity to Christchurch, with construction beginning in 1911 and completed with three generating units in 1914. Following its initial construction, the twin 66 kV transmission lines connecting the power station with Christchurch's Addington substation were the longest (over 100 kilometres (62 mi)) and highest voltage in New Zealand.[2]

More generators were added as electricity demand grew and the transmission system extended to reach Rangiora in the north and Oamaru in the south. By the early 1930s, Coleridge had reached capacity, and was supplemented in 1934 by the commissioning of the Waitaki Dam and in 1935 by extending transmission lines south to join Coleridge/Waitaki to Dunedin's Waipori scheme.