Otututu says the West Coast pays some of the highest average cost for electricity in New Zealand.
"With the intensifying need for electrification of the New Zealand economy, there is a growing demand for clean, renewable energy generation projects and a need for capacity and resilience within the West Coast grid which can be subject to the costly disruption of power cuts."
A 2008 report 'Renewable Energy Assessment' for the Government's Energy and Efficiency Conservation Authority identified the Otututu River as a suitable site for an 11.1MW power scheme.
"The scheme will sit within a number of tenures. The intake gallery will be within Land Information NZ [LINZ] administered land, the pipeline will be within the conservation estate and the powerhouse will be within private land," the company's proposal says.
The site was strategic, with a number of heavy electricity consumers in the vicinity, including the new Blackwater Gold project across the Grey Valley, and proximity to the Inangahua-Dobson feed line.
Water would be collected via an intake gallery at the confluence of Mirfin Creek, on LINZ land. It would then be taken via an 8km pipe through conservation land.
"The pipe will then create 65m head pressure as it drops into [the] powerhouse to be located within private farmland."
That water would then be returned to the Otututu River, and energy fed into the Dobson-Blackwater power line.
The scheme would involve earthworks and vegetation clearance for the intake, the pipeline and access tracks.
Otututu notes many renewable energy scheme proposals failed at the permitting or consenting stage due to effects "on the receiving environment".
"Our proposition is unique as the Otututu catchment is not considered ecologically unique or within either a significant or outstanding natural landscape.
"There are also no known culturally significant sites within the immediate area," the company says.
It would be the furthest electricity generator from the Alpine Fault, at 45km.
At present, West Coast electricity mostly comes from the Nelson region via Inangahua to Dobson. This supply is supported by loads from the south via low-capacity lines from Lake Coleridge in Canterbury, and in limited capacity a connection between Dobson and Kumara.
"Typically, around 8.5 per cent to 13 per cent of electricity is lost in transporting to Westpower's network."
It says the possibility of the Grey Valley scheme has been discussed for 15 years.
"Peak demand for electricity in Westland has been forecast by Westpower Energy to grow from 50MW in 2012 to 70 to 80MW by 2030, while electricity consumption is forecast to grow from 300GWh to 400GWh per annum by 2030," Otututu says.
A founding shareholder of Otututu Energy Ltd, Darryl Sycamore is in his third term as a Guardian of lakes Manapouri, Monwai and Te Anau - the scene of the first significant environmental action by conservationists in the 1970s.
The company says it is now exploring options to transfer a "significant percentage" of the company ownership to the West Coast.
