The electricity transmission link between the Waitaki Valley and Roxburgh will need to be upgraded even if Meridian Energy does not build a new power scheme on the lower Waitaki River, according to Transpower and an energy sector consultant.
Both gave their views yesterday at an Environment Canterbury hearing in Christchurch considering four resource consent applications by Meridian to build the north bank tunnel concept scheme between the Waitaki dam and Stonewall, near Ikawai, on the river's north bank.
It is only one of several new power schemes being proposed for the lower South Island.
Transpower planning and development manager David Boyle said yesterday if there was more electricity generation in the Waitaki Valley then it was likely some upgrades of the transmission grid would be required.
It was investigating an upgrade, although that was not specifically associated with the tunnel scheme.
Electricity flowed from the Waitaki Valley to Southland, and from Southland to the Waitaki Valley and Christchurch.
Transpower had also recently received draft approval from the Electricity Commission to upgrade the high-voltage direct-current link between Benmore and Wellington.
Energy consultant Jim Truesdale of Concept Consulting Group said there were three transmission routes out of the Waitaki Valley - the high voltage link to and from the North Island; to Canterbury and the upper South Island via Christchurch; and to and from Otago and Southland via Roxburgh.
Transpower was predicting new electricity generation proposals in the upper South Island would defer the need for transmission upgrades from South Canterbury to Christchurch.
Transpower was investigating options to increase transmission capacity between the Waitaki Valley and Roxburgh and intended to submit a proposal to the Electricity Commission this year.
The tunnel scheme could advance the need for such an upgrade, although it was not clear how much could be attributed to the Meridian proposal.
