$30m power boost for Aucklanders

Mighty River Power is awaiting the arrival of a $30 million turbine generator to pump more power into Auckland at times of peak demand.

The state-owned electricity company yesterday said the gas-fired turbine, which could produce 45MW of power, was due to arrive from the United States in mid-August.

It would be installed at Mighty River's Southdown plant in Penrose in early December, and would be used when power demand was at a peak, when electricity prices were high, or when hydro lake inflows were low.

Mighty River Power revealed its turbine purchase in April, but it used a visit by Energy Minister David Parker to Southdown yesterday to talk more about the purchase.

Chief executive Doug Heffernan said Auckland's power demand was increasing by 45MW a year, and that could be contained by the new turbine.

But upgrading the transmission system to and around Auckland was a priority.

"The ultimate solution for continuity of supply is transmission - you can't supply continually with generation because the interconnections here in Auckland are too weak."

The security of Auckland's power supply has been in the spotlight. National grid operator Transpower has been under fire for its plan to build a new string of pylons into the city from Waikato.

A blackout in Auckland last month highlighted the extent of the city's dependence on the Otahuhu substation, which has design faults.

Mr Heffernan said the size of Auckland and the growth rate of the region made transmission upgrades important.

Building new energy-generating capacity close to areas of high demand such as Auckland, as well as managing demand, were part of the solution.

Mr Parker said yesterday said the new turbine going into Penrose represented about 10 per cent of the additional generation capacity that would be coming into production in the next 12 months.

The turbine would increase Southdown's total generating capacity to 170MW from 125MW.