Electricity use in Otago rose 10% on Monday as residents kept warm during the worst snowstorm to hit coastal Otago in 15 years.
As temperatures hovered just above 0degC for most of Monday and residents stayed at home rather than taking to icy, slushy roads, South Island power demand stayed constant throughout the day, Transpower figures show. Normally, South Island electricity demand drops between about 1pm and 5pm.
As the storm hit much of the country, New Zealand's power usage increased to 131.13GWh.
The South Island used 45.34GWh and the North Island 84.8GWh.
Peak demand for the whole of New Zealand was 6781MW at 6pm on Monday night.
Wellington was the only area to break records for power use, consuming 11.58GWh compared with 11.2GWh on June 29, 2009.
Transpower figures show Otago-Southland's power use on Monday was 25GWh - the highest it had been all month.
Otago's Delta network services manager Lindsay McLennan said Monday's cold weather was reflected in higher energy use on the Dunedin network, which was 10% higher than last Friday.
In Central Otago and Queenstown Lakes, energy use was up only 2% on last Friday, as demand had been higher in Wanaka and Queenstown because of the influx of skiers during the school holidays.
"We expect that these levels of use will remain for most of this week due to the frosty mornings."
Overall, energy use was similar to the worst winter days in 2010 and 2009, he said.
