inchbonnie hydro nz

Inchbonnie Hydro is a 1.7 megawatt run of the river power scheme drawing water from 2 stream high up in the Hohonu range between Greymouth and Hokitika. The 2 catchments feeding the hydro scheme have a combined area of 11 sq km.

Commissioning of the scheme was completed in January 2016 with power flowing into the Westpower network. The annual energy output will meet the requirements of 1200 average NZ homes.

The design represents the latest thinking on hydro construction in difficult terrain for minimal environmental impact. The intakes are small structures built into the stream beds with no large dams or extensive earthworks affecting the natural characteristics of the surrounding area.

The upper reaches of the penstocks are on DOC land and are laid through the bush without the need for major clearing or road works.

2.7 km of pipe connect the intakes at an elevation of 490m to the power house on the banks of the Taramakau river. The total amount of water drawn from both streams is 0.65 cubic meters per second depending on the rainfall. The water flows from the powerhouse through a tail race back into the confluence of the 2 streams where they enter the Taramakau.

The power scheme makes a significant contribution to New Zealand's emissions targets. The energy from Inchbonnie Hydro will reduce NZ’s CO2 emissions by 4000 tons per annum compared to energy from combined cycle gas.

The turbine is a horizontal axis pelton machine designed and built in New Zealand by Hydroworks. The synchronous generator operates at 690 volts and the power is transformed on site to 11,000 volts for injection into the Westpower networks. West Coast company Electronet designed, built and installed the station control systems and all electrical works.