If you popped the heater on before you got out of bed this morning, you might have pondered what your next power bill will look like.

The middle months of the year are often the most expensive for household electricity.

But the Energy Efficiency and Conservation Authority says there are some energy-saving things that you can do that could help cut your bills, without denting your lifestyle too much.

"We've really tried to focus on things which are either no cost or at least very low cost and try to quantify the benefits of each measure," said Gareth Gretton, EECA's lead adviser on energy efficient appliances. "People can think about what exactly works for them and their household and make trade-offs for themselves."

These are the seven things EECA recommends doing - and how much you could save by doing them.

Only heat the rooms you're using: EECA said that households using electric heating could save about $300 a year if they switched to only heating the rooms they were using. This would reduce electricity demand by about 10 or 15 percent.

Keeping your house heated to 21°C rather than 23°C could also save 2 percent of your power, or about $40 a year.

"There's always this tradeoff with you know 'how warm do I want my room to be' and you know 'am I kind of on the edge of my comfort level or I'm actually feeling cosy'," Gretton said. "Maybe think about just trying to heat the rooms you're actually using at a given time rather than trying to heat the whole house and not necessarily being comfortable in any one room … it's not about being uncomfortable, it's about trying to use energy wisely."

He said draught stopping was also important. "This is very dependent on the house you're in but there's obviously still lots of people living in draughty houses. It's a perfect time to look at that - this is very much house by house but you could be looking at up to $100 from that one in the winter."

Switching to cold water in your washing machine: Washing your clothes in cold water rather than warm will reduce consumption by 1 percent, EECA said. Gretton said based on one wash a day, a household that moved five out of seven washes to cold water would save about $50 a year. "We're sort of so used to machines defaulting to warm and just pressing the start button but all it takes is a click of the button to move down to cold," Gretton said. "If all you're doing is kind of freshening up some clothes and they don't have any really hard-to-shift stains in them, then they're going to come out clean and you're going to save yourselves [money]."

Turning off appliances that you aren't using: If you can turn off things like your heated towel rail, TV or second fridge you could reduce your electricity demand by about 8 percent, or a saving of $200 a year. "I think some households do have a second fridge maybe running in the garage or something like that," Gretton said.

"It's probably the number one energy vampire that's in your household because you might have chucked it in your garage and thought 'oh that'll be useful at Christmas'. Then it'll end up running all year because you forget about it. Empty it out and turn it off, then turn it back on again when you need it."

Close the curtains at sunset: Closing the curtains at sunset could save you 3 percent of your power, or $80 a year, EECA says. Gretton said it was mostly "common sense" but sometimes a "little nudge" would remind people of the small changes they could be making.

Reducing your hot water temperature: Limiting your hot water to 60°C could save 3 percent in power.

Vacuuming your heat pump filter: Remembering to vacuum your filter could reduce your power use by 2 percent or about $50.

Time your power use: If you're on a plan that gives you cheaper power off-peak, make use of it. Gretton said a number of households were on time-of-use plans, where power is cheaper at certain times of day, but were not using them to the best advantage. Shifting appliances to off-peak times, particualrly things like clothes dryers, could help save money. "Dishwashers are kind of an easy one in some ways because they often have a 'delay start' function. The saving we're modelling for that one is around $150."

-RNZ