One of the hero appliances of the electrification agenda is the induction cooktop. They are clean, can operate on 100 per cent renewable energy, and have benefits for health and safety compared to gas cooking. However, they may also have vampire tendencies when it comes to energy use.
Induction cooking is gaining traction both in commercial kitchens and residential properties, which is terrific from the perspective of reducing dependence on gas. However, this type of appliance also has a potential downside for energy consumption.
Steve Hennessy, engineer and CIBSE ANZ committee member tells The Fifth Estate he installed an induction cooktop at his home, and it has been “every bit as good as gas for controllability”.
It’s also easy to clean, he says, there are no fumes (unlike gas) and it is faster for cooking than an electric coil or electric halogen cooktop as all energy goes directly into the food via the cooking equipment – none is wasted as radiant heat.
What has proven to be a less pleasant surprise is the stoves use a considerable amount of standby power, even when they appear to be switched off.
Applying some science
Hennessy tested this with his own electrical meter – calculating the difference in energy use between having the stove sitting idle and switched off at the wall, and the difference between it simply sitting idle.
It equated to about 80 watts per hour of energy waste, which over a year, he estimated comes in at around 700 kilowatts, adding around $245 to total energy bills at an average 35 cents/kilowatt hour residential energy supply cost.
He notes that his cooktop does not have a clock, or any other smart or digital feature that could account for the standby power use. In speaking to a few other people who have also installed induction cooktops, he found a similar story. Vampire energy use was high unless the stove was switched off at the wall.
This might sound simple, however, as some of his contacts reported, the main switch for a stove may be located behind the unit, or in an adjacent cupboard or underneath, making it varying degrees of inconvenient to remember to switch it off after cooking. In some properties, the switch may be almost impossible to locate, particularly for occupants who don’t know what they might be looking for.
Hennessy notes that under the construction code wiring rules, the main switch for a stove is supposed to be within two metres of the stove. Ideally, logic suggests it should also be visible and accessible.
(Try this at home – if you have an induction stove, where is the main switch at the wall? Let us know in the comments!)
No energy rating scheme, yet
Another challenge with induction cooktops and energy use is that currently there are no regulated Minimum Energy Performance Standards (MEPS) for the appliances.
The Fifth Estate contacted the federal Department of Climate Change, Energy, the Environment and Water, which administers appliance energy rating schemes, and it confirmed that currently there are no minimum energy performance standards for induction cooktops and the appliances are not required to display an energy rating label.
This may change. The source at DCCEEW said the Equipment Energy Efficiency (E3) Program is currently looking at the energy efficiency of home cooking appliances, including induction cooktops. They added that there is a possibility the E3 program may publish options for introducing MEPS and energy rating labels for induction cooktops and other domestic cooking appliances later this year.
What manufacturers should do
Ideally, manufacturers should be designing the appliances so they do not have such high vampire energy demand. Hennessy suggests an improvement to the electrical design that ensures they automatically power down to minimum energy consumption – a maximum of one or two watts per hour – would be optimal.
Manufacturers probably also need to alert consumers about the standby power use and explain why it is so high.
What stove users can do
Energy efficiency 101 involves changing behaviour – so just as switching chargers, laptops, desktop computers, TVs and other equipment with vampire tendencies off at the wall will reduce energy use, a similar practice can be applied to cooktops.
If you can find the switch, that is.
I’m in the U.S.. I can’t find a switch for my induction oven or stovetop
I have a Miele induction stove and Emporia Energy monitoring on the circuit. My stove does not show any energy consumption when not in use.
Also, you have mixed up your energy and power units. It should be “It equated to about 80 watts of energy waste, which over a year, he estimated comes in at around 700 kilowatt hours, …”
Hi PC
Interesting – I think that if anything, this further highlights the need for minimum energy performance requirements. If your induction stove can shut down to zero when not in use, why can’t all stoves? I don’t think we should single out any particular manufacturer (mine is a different brand, the person who first informed me that this might be an issue, has another, and a friend up the road who claims an even higher standby load than mine, has another brand again).
My meter is not a power analyser per se, so power factor is assumed (readings were taken at the meter, and not at the appliance). The person who first brought this to my attention used his smart meter data.
Even if the consumption was half of what was measured, it would still equate to significant energy wastage.
Re the calculations – 80W/hr = 1.92kW per day = 700kW per annum. Yes there may be a reduction if we factor in use time – in my case the 700 would drop to maybe 686kW/annum – but that’s still a significant amount of wastage.
As Willow alluded to, ‘you will never save more energy than by turning something off [at the power point]’
Steve H