Queenstown households used 90% more power in June than in April, an online electricity retailer says.
Powershop head Ari Sargent said in a statement monitoring usage and making some smart tweaks can get power usage under control, which keeps bills down.
Water heating accounted for about 30% of a typical household's energy bill, which cost the average household $650 a year, Mr Sargent said.
"Simple actions like turning cylinders down to 60degC and wrapping them to retain heat, replacing washers to stop dripping hot taps and washing clothes in cold water can all add up.
"About 80% of hot water is used in showers.
"If a shower can fill a 10 litre bucket in less than a minute, installing an efficient shower head could help save up to $150 a year, while still giving you a good shower."
Heating and cooling was another big power user, accounting for almost 35% of a typical household's energy consumption.
"Good insulation is the best way to get this under control, and make sure the warmth your heating system uses doesn't escape," Mr Sargent said.
"Certain appliances act as vampires, sucking electricity even if they are not in use.
Unplugging appliances like phone chargers and computers when they are not being used can help keep costs down."
To help to chart electricity use and monitor changes, Powershop launched a free online tool called PowerSaver in association with the World Wildlife Fund.
It helps householders understand daily power usage and set targets to reduce it and provides easy tips to keep costs down.