Households are desperately trying to cut back on using electrical appliances as average energy bills are soon set to hit £3,549 a year.
To maximise your savings, it helps to know exactly which appliances drain the most electricity.
David Miles, 46, from Essex, bought a smart plug to monitor how much energy each appliance in his home uses.
He went around his house plugging different appliances into the smart plug then monitoring energy performance via an app on his phone.
“It tells me how much power each appliance is consuming at any given time and its average daily consumption," he told Express.co.uk .
The app also allows him to turn the appliance on or off using his phone when he is out of the house.
David got a shock when he used the plug on his 25-year old American-style fridge freezer.
“Incredibly, it ate up a fifth of my entire electricity bill," he said.
Over the course of a year, this fridge freezer was using a staggering 1,600 kilowatt hours (kWh) of power.
“That’s the same as our friend's hot tub,” David says.
Today, each kWh of electricity costs 28p, according to regulator Ofgem.
So at the moment, David's fridge is costing him £448 a year to run.
From October, when the energy price cap jumps from £1,971 a year to £3,549 a year for the average home, electricity will jump to 52p per kWh, a rise of almost 86%.
This will drive up the cost of using his American fridge freezer to a staggering £832 a year, and David is taking action.
New fridge freezers cost between £350 and £2,000, depending on the make and model, but David considers buying a new one a good investment.
Typically, a brand new fridge freezer will use a maximum of 400 kWh of electricity each year, which will cost him £208 a year when prices jump.
“That will save me at least £624 a year, so upgrading my fridge freezer will pay for itself in two or three years, plus I will also slash my home's carbon footprint," he said.
David’s experience is far from unusual.
Research from consumer champion Which? showed that American fridge freezers are the second most expensive household appliance to run.
Its research was carried out on June 30, when electricity cost 28p per kWh, but we have updated the numbers to reflect October’s 52p per kWh charge.
David, who lives with wife Jane, 48, and daughter Enfys, 17, and Alfie, 14, is bracing himself for October’s energy price rise, when he expects to spend £430 a month on electricity alone, with gas bills come on top.
He is taking other measures to cut his energy usage, such as upgrading his gas boiler which he reckons will cost £4,000 but cut his gas bills by 20%.
“We could get our money back in four or five years," he added.
David, whose firm The PPC Machine helps mortgage brokers and financial advisers find leads, says his toughest job is to make his children aware of the need to save energy.
He joked: “I'm teaching them that light switches can turn off as well as on.”