The Scheme

The Solid Energy scheme operates by collecting water from the Stockton Plateau (much of this water is affected by historic and current mining) and conveys it to three linked reservoirs where the acidity is corrected and sediment plus eco-toxic levels of dissolved iron and aluminium settled out. A penstock would then convey the treated water to a power station located within Solid Energy’s existing Ngakawau Coal Handling Facility before returning it to the Ngakawau River.

The scheme uses proven technology and is technically similar to the Cobb Power Station, near Nelson. Unlike other proposals being promoted in the same area, this scheme would avoid the costs and construction risks associated with underground and undersea tunnels.

Creating 176 Gigawatt hours (GWh) of renewable electricity and improving the ability of Solid Energy to manage the effects of water runoff from the mining areas at Stockton, the proposal would fit neatly into the environment and would further improve the water quality in the Ngakawau River.

This briefing paper gives an overview of the proposed scheme.

Before moving to the detailed design phase, Solid Energy will first seek the resource consents and other permissions it will need to allow the scheme to go ahead.

If a decision is made to go ahead following the consenting phase, it would take approximately a year to complete detailed design and three years to construct the scheme.