Prime Minister John Key says an inquiry is needed into whether there was sufficient back-up in place after the power cuts in Auckland yesterday - but has warned that if that inquiry finds better backup systems are required it will contribute to higher power prices.
Mr Key said there would need to be an inquiry into what went wrong and the response to that.
"We know there was a fire, the question is was there enough redundancy built in there."
He said if that inquiry found greater contingency systems were needed, it would have a cost. Vector was a controlled monopoly and its charging and costs were set by the Commerce Commission.
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He said the increase in power prices over the past six years was primarily driven by the costs of upgrading the national grid and power companies investing more in infrastructure.
"I know people will say 'deliver me the gold-plated solution.' But the gold plated solution has implications for consumers."
He said Vector had done well in getting power restored and there were about 20,000 houses still affected.
Paymark today released figures showing the Auckland power outages had caused an estimated $4.3 million drop in spending.
The payment company said total spending in Auckland and Northland yesterday was $46 million, down $800,000 or 1.7 per cent on the previous Sunday.
That figure included sectors that appeared to be largely unaffected by the outage.
However, the drop was larger across some sectors. Spending in the clothing, apparel, jewellery, general retail and food sectors, excluding cafes and restaurants, totalled $23.3 million yesterday - down $2.7 million or 10.3 per cent on the previous Sunday.
Total spending throughout the rest of New Zealand was up $4.5 million, or 6.7 per cent, yesterday.
Paymark said that had Auckland seen the same average growth as elsewhere in the country, the overall reduction in spending was likely to have been around $4.3 million.
5 Top power outage tips
1 For light, a torch is safer than candles.
2 Switch off sensitive electronics such as the TV, computer, stereo and video recorder until after the power is restored. These can be affected by a power surge when power comes back on.
3 Keep the fridge closed. Food in refrigerators and freezers will last longer if the doors are closed.
4 Turn off all appliances, including the stove, kettle, and heaters. This ensures they don't come back on when no one is home.
5 Street lights and traffic lights may not be working.
Auckland Civil Defence have released this graphic earlier today, showing the affected areas and when they should be up and running again:
- additional reporting APNZ staff