Contact power station out of action for two months

The Otahuhu power plant was shut for maintenance at the beginning of this month. Photo / Greg Bowker

Contact Energy hopes to have its Otahuhu gas-fired power station back in service in two months after cracks were found in a generator.

The shutdown of the 10-year-old plant marks the end of a rough year for New Zealand's biggest listed power company.

It was shut for maintenance at the beginning of this month and had planned to resume generation from the end of next month.

The 380MW combined cycle power station uses hot exhaust from its gas-fired turbine to produce steam for more generation.

Cracks in welds in the power station's heat recovery steam generator need to be repaired.

"It's not entirely uncommon - we've had cracks in welds before and given the time of the year we thought we'd fix it now," a Contact spokesman said.

Power use during January drops markedly, although the increased use of heat pumps to cool homes has increased consumption on very hot summer days.

Contact could bring on its 400MW combined cycle station in Taranaki but "there's no doubt you'd prefer to have your plant available," the spokesman said.

Contact - majority-owned by Australia's Origin Energy - had a 50.4 per cent profit plunge to $117.5 million for the year to July and for much of the past six months has been hit by low wholesale power prices.

Contact shares closed up 1c yesterday at $6.08.