Donna Swain knows the first thing her son does when he gets home from school at 4.45pm is switch on his PlayStation.
As soon as it gets booted up, the household's electricity usage jumps up.
The biggest spike is at 7pm when the whole family is home, laptops and iPads are being used for homework, the television's on and dinner's being made.
She can tell you all this with great precision, because power companies are rolling out new technology that allows New Zealand households to monitor their energy usage right down to the hour and even by rooms. And with the country having its first cold snap of the year this week, people will be noticing a steep increase in their bills as they try to keep warm.
These "smart" tools are helping families reduce their power usage. In the case of the Swains, after joining up to Mercury Energy's Good Energy Monitor (GEM), they cut one of their bills by $60.
When they joined the programme about two months ago, their electricity consumption history was loaded into their profile.
They can now monitor their usage by half-hour, day, bill and year, compare it to similar households and see how the weather influences their power use.
The Swains have also entered savings goals and the tool helps keep them on track and in control of their power bill.
Mrs Swain, who admitted she was becoming quite addicted to saving power, said being able to track her usage helped "make it real". It also helped her to budget for their next bill more accurately.
"We all know that we should turn our lights off and turn things off at the wall, but it's not until you can see it on your screen that it really hits home."
Reducing their electricity usage has become an effort by the whole family and Mrs Swain is using the drive to educate her children about power, hoping to build lifelong habits.
Her 13-year-old son, Quinn, has managed to cut his power consumption by a third, mostly by cutting down his PlayStation time and Aleesha, 9, has switched from eating her favourite snack of spaghetti to cereal because it doesn't use any electricity. The family is also forging new habits.
"It takes a few moments a day. It becomes a daily routine to go around and turn things off before you go to sleep, like cleaning your teeth before you go out the door."
Mrs Swain told the Weekend Herald that the GEM tool had changed her life and had helped make her accountable for the power she was wasting.
Powershop's design director, Simon Coley, told StopPress he thought Mercury was "obviously trying to 'sell' one of the same benefits as Powershop.
"All the major retailers have endeavoured to develop technology to help customers measure and monitor their power usage and leverage their investment in smart metering. Meridian and Genesis have both had online usage monitoring tools for a while."
A year ago, Genesis launched its Tomorrow Street project - New Zealand's first advanced energy neighbourhood. In a suburb on Auckland's North Shore, 15 houses had different energy saving products installed and their homes have had their power consumption monitored.
The programme successfully recorded savings every month - the highest was in March with a 28.31 per cent saving across the entire neighbourhood compared to the previous year.
The biggest monthly saving for a single house was 59 per cent, following the installation of PV solar panels and insulation.
Eight of the 15 households saved more than 30 per cent of their energy consumption in March this year compared with same month in 2012.
Genesis spokesman Richard Gordon said the initiative provided the company with a real-life, real-time learning tool to trial new products and develop customer solutions relevant for modern lifestyles.
"By identifying and addressing the energy efficiency weaknesses of a small test group of New Zealand homes we've been able to gather data and feedback that could potentially make a difference to all our customers in the future."
Energy Efficiency and Conservation Authority (EECA) chief executive Mike Underhill commended Genesis and Mercury for blazing the trail for power conservation.
"Good on these two for taking the lead."
He said there was a growing push by New Zealanders to save power. "People are much more aware of the environment these days, but with rising power bills they're also wanting to save as much as they can. There's also a health interest too."
Mr Underhill said the average household used about 60 per cent more energy in the winter than they did in the summer.
New Zealand houses were generally "pretty appalling" compared to other parts of the world, because they had little or no insulation and were draughty and cold, so it took extra electricity to heat them, he said.
"We know there are significant health benefits from living in a warm dry home, so we have a whole series of tips even if you don't have these smart meters."
For those on a tight budget, Mr Underhill recommended closing the blinds at night to keep heat in and putting draught-stoppers at the bottom of doors.
Changing lightbulbs to energy efficient ones could save an average family about $110 a year, putting heated towel rails on a timer saved about $100 a year and fixing a hot dripping tap save about $60 a year.
Electricity Authority chief executive Carl Hansen said they promoted competition and developed rules to be conducive to innovation.
"These kinds of 'smart tools' build on the capability of devices such as smart meters and provide better consumption information for consumers," he said.
"They allow consumers to understand their consumption patterns better and therefore give greater ability to control and respond to them."