It must decide in July whether to pay a higher price for 172 Megawatts of its 572 Megawatt electricity supply contract, starting in January 2017 and has been deferring capital expenditure as it weighs up whether to maintain the smelter at current full production, reduce operations or announce the smelter's total closure.
Despite improvements in the global price of aluminium, the New Zealand dollar had strengthened in the past month, largely negating the benefits of any price uplift, Kidd said in a note to clients issued on May 23.
"With aluminium market conditions remaining depressed, forward NZAS economics remain very marginal and with NZAS facing a material increase to the cost of its 172MW CFD (electricity contract) from 1 January 2017, we think the decisions NZAS faces over the next few months remain finely balanced," Kidd said.
That was despite the proposed transmission price reductions reducing electricity costs from around $59 per MW hour to $54.80/MWh under contracts, rising to an estimated $56/MWh for the 172MW tranche to be renegotiated from January next year.
Whether the EA's transmission pricing methodology decisions represented "just enough" to continue operations as they are now "remains in our view open," said Kidd, who noted the new transmission charges don't kick in until 2019.
"The interaction of deferred capex, opex (particularly electricity cost) and plant capacity optimisation in NZAS's decision spectrum is opaque to those ... not directly involved with the plant," he said. "While it is true to say that the premia NZAS production attracts provide a critical point of positive revenue differentiation versus virtually every other smelter globally, the importance of this is lost if the smelting cost base approximates or even exceeds that revenue premium."
Woodward Partners estimates the current value of the Japanese market premium for the high-grade metal produced at Tiwai Point to be around US$100 per tonne, down from a recent peak of US$400 a tonne in 2014.