Green Building Forum - Microwave power consumption

Microwave power consumption

jms452 — Tue, 01 Jun 2021 08:24:52 +0100

Slightly embarrassingly our 25 year old microwave clock is uses 10W (Which is about 15% of our total electricity consumption!).

It's also nearing the end of its life so I'm wondering if microwave standby has improved in line with other items but looking around the usual sites I can't see standby power mentioned anywhere.

To avoid me being 'that guy' with an energy eye plug arguing with the assistant in Currys:

Is there a data base for microwave standby power anywhere I'm missing?
Has anyone on GBF measured the standby of any current models?

Microwave power consumption

djh — Tue, 01 Jun 2021 10:44:09 +0100

Posted By: jms452Is there a data base for microwave standby power anywhere I'm missing?

There's one for American products at https://www.regulations.doe.gov/certification-data/CCMS-4-Cooking_Products_-_Microwave_Ovens.html#q=Product_Group_s%3A%22Cooking%20Products%20-%20Microwave%20Ovens%22

I think the rules nowadays are something like < 1 W on standby.

I'm very impressed by your total electricity consumption (under 600 kWh per year !!!?)

Microwave power consumption

jms452 — Tue, 01 Jun 2021 11:36:08 +0100

Posted By: djhI'm very impressed by your total electricity consumption (under 600 kWh per year !!!?)

Continuing the slightly embarrassing theme it's actually 6% when I do basic maths right

Microwave power consumption

djh — Tue, 01 Jun 2021 16:05:29 +0100

I'm still very impressed ~1500 kWh

Microwave power consumption

Jeff B — Tue, 01 Jun 2021 17:52:39 +0100

I must admit I would never have given the clock on our microwave oven a second thought regarding power consumption. As it is we only turn the microwave on when we want to heat something and then turn it off at the wall switch again. I don't like the idea of the power being on to the beast 24/7 - irrational really because I don't worry about the TV!

Microwave power consumption

Ed Davies — Tue, 01 Jun 2021 18:45:15 +0100

I switch all kitchen appliances off at the wall switch when not in use [Â¹]. Leaving power on to devices which are built as cheaply as the manufacturer can get away with which get temperature cycled repeatedly seems a bit irrational to me.

[Â¹] except the washing machine here because some megabrain put the socket behind the thing so it's completely inaccessible - I've never even bothered to look at it.

Microwave power consumption

revor — Tue, 01 Jun 2021 19:04:28 +0100

1500 kwh agreed is very impressive that is just 4kwh per day. I thought we were doing well at about 6 to 8 during summer and around 12 in winter. About 1 kwh is used overnight by constant on appliances i.e. fridge freezer MVHR router etc. So 4 kwh per day is great how do you manage that? At moment costing us nothing grid use practically zero as powered by the PV and battery when no sun. Occasional days we are 100% self sufficient most days 97% depends if we use high loads like showers ovens and grills. Test will be winter.

Microwave power consumption

jms452 — Tue, 01 Jun 2021 22:52:29 +0100

Posted By: revor1500 kwh agreed is very impressive that is just 4kwh per day. I thought we were doing well at about 6 to 8 during summer and around 12 in winter. About 1 kwh is used overnight by constant on appliances i.e. fridge freezer MVHR router etc. So 4 kwh per day is great how do you manage that?

There's only three of us, 4kW PV, Gas heating & hob, LED lights, A+++ appliances, chest freezer and under counter fridge, v. modest sized single tv, loadshift into the day on dishwasher & washing machine, Gas heating, slightly obsessive vampire hunting (hence the embarrassment at the microwave).

How low is this? - my only baseline is that I have to select low usage and then remove a bit on uswitch..?

edit: in 2020 we were 1338kWh but not a typical year.

Microwave power consumption

revor — Wed, 02 Jun 2021 07:59:25 +0100

Great to have comparison as we have also been somewhat OTT about consumption but never know where we are compared to what others consume all one tends to have is average figures quoted by energy companies.We are also all LED, A++ appliances and all electric apart from gas heating. Is the consumption you quote just from the grid i.e what you pay for or does it include your PV usage as well?.

Microwave power consumption

RobL — Wed, 02 Jun 2021 08:48:57 +0100

We are similarly trained now! When my daughter got a lava lamp, I insisted on it having an auto off, so it didnâ€™t pull 15W forever. Our elec garage door is just off, as it takes a cheeky 10W standby.
2 years ago our consumption was 1477kWh (we have 4kWp PV though).
Now we have an elec car on a V2G trial. It barely moves due to covid. Annual elec useage has gone through the roof, and is 7300kWh. Erk. Most of it goes back to the grid at peak times, and they pay us for that (our elec+gas â€˜billâ€™ is likely to be negative), but still looking at that number makes me queezy. Annoyingly their billing software isnâ€™t as great with elec to them as from them, so it makes dissecting whatâ€™s happening difficult. Also, elec to them is mixed up with PV as we only have 2 meters still.

Microwave power consumption

jms452 — Wed, 02 Jun 2021 20:40:30 +0100

Posted By: revorIs the consumption you quote just from the grid i.e what you pay for or does it include your PV usage as well?.

Unfortunately yes, it is currently impossible to disentangle the two due to self usage of PV.

Although we will shortly be moving to metered export with smart meter and outgoing agile.

I'd guess <2000kwH/yr 'all-in' based on winter usage.

Posted By: RobLWe are similarly trained now! When my daughter got a lava lamp, I insisted on it having an auto off, so it didnâ€™t pull 15W forever. Our elec garage door is just off, as it takes a cheeky 10W standby.
2 years ago our consumption was 1477kWh (we have 4kWp PV though).
Now we have an elec car on a V2G trial. It barely moves due to covid. Annual elec useage has gone through the roof, and is 7300kWh. Erk. Most of it goes back to the grid at peak times, and they pay us for that (our elec+gas â€˜billâ€™ is likely to be negative), but still looking at that number makes me queezy. Annoyingly their billing software isnâ€™t as great with elec to them as from them, so it makes dissecting whatâ€™s happening difficult. Also, elec to them is mixed up with PV as we only have 2 meters still.

Will be in the same boat on outgoing agile (especially if we go incoming agile too). Interesting scenario where it will be cost effective to move loads to the early hours and sell the PV, particularly in the evenings when the prices spike.

Microwave power consumption

wookey — Sun, 18 Aug 2024 12:27:10 +0100

Yes. Same issue here. My 1990s microwave (bought second hand in 1994) uses 4W standby, which does indeed add up to a surprisingly large annual consumption. We discovered this from a domestic appliance metering trial a few years ago.

Our solution has been to put the microwave on a switched extension lead. It is turned on to be used, and turned off again when finished with. We sometimes forget for a while, but overall this essentially solves the problem. Now we've kept it going for 30 years it's practical a family member, and I'm loath to get rid of the thing. I even have a spare magnetron in a box should it ever die :-) Pretty sure they don't make modern machines with this sort of longevity. (I have had to give it a new capacitor, new bulb and new incoming microwave channel screen in that time).

It has now developed a habit of stopping with 48 seconds to go, if the initial period was more than 1m40s which is really strange. What's special about 48 on a digital timer?

Microwave power consumption

djh — Sun, 18 Aug 2024 17:00:09 +0100

I had a similar situation with my EV charger. I originally fitted a dumb Chargemaster unit when we built (got it free in 2013/4/5 ish) and it had a standby power of over 15 W, so I isolated it whenever I wasn't using it. It recently failed and the replacement has a standby power of 0.09 W (I'm very impressed!) so it stays on all the time.

It's lucky it has a low standby because I *have* to leave it on all the time. It's supposedly a new-fangled 'smart' charger but it's so smart that it can't cope with my network and won't start at all. Luckily there's an emergency mechanism - press a button five times and then another five times and it goes into 'dumb' mode where it's permanently available for use. I control charging using my car's systems.

The problem seems to be that to get it going in smart mode you have to pair it with a phone app (which is fine) and then it needs to 'dial home' over the Internet. But any new device appearing on my network gets a default profile that prevents connection with the Internet. And by the time I've gone to my router's admin screen and said that the new device should be given permission, the charger has decided the network is useless and has given up!

The standby power isn't constant - there are spikes of 1W in amongst periods of 0 W. There seem to be most 1 W spikes during the mornings, with fewer during the afternoons and none at all in the middle of the night. Every day is different; I have no idea what it's doing or why. ?

Microwave power consumption

wookey — Sun, 18 Aug 2024 17:51:58 +0100

Which device has that low standby power? 0.1W is indeed commendable. (Although presumably everything has to meet the EU <0.5W standby requirement these days so nothing newer than about 2009 is 'bad').

Microwave power consumption

djh — Sun, 18 Aug 2024 20:51:12 +0100

An Evec VEC01. We definitely bought and installed the Chargemaster after 2009!

Microwave power consumption

Simon Still — Tue, 20 Aug 2024 11:25:39 +0100

https://storage.topten.eu/source/files/STANDBY%20Topten%20EU%20policy%20recommendations%20Feb%2013.pdf

so the 'sub 1w' rule came in 2010 (though it was 2w if there was a display with info - ie a clock), then dropped to 0.5w in 2013 according to the above link.

Further reductions coming in a few years covering many more items. But no mention anywhere of cookers/microwaves strangely. (and some weird exclusions - why would the limit remain <1w rather than 0.8W for a Tumble Drier with a display. but for that matter, why would a tumble drier need an always on display in any case?)

https://www.complianceandrisks.com/blog/eu-commission-approves-new-ecodesign-standby-regulation/

Microwave power consumption

Gareth J — Tue, 20 Aug 2024 12:26:00 +0100

What about a simple, mechanical one? No clocks, digital gubbins to break or buy in the first place. Or struggle to recycle. No annoying settings to learn how to navigate. Cheap to buy too.

Fair enough if you value the settings that some one with but as a machine to make food hotter, I'm quite satisfied with ours with just a mechanical timer that goes bing.