The cost of a microwave on standby

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Spectric

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You may be right with domestic meters that just use induction to operate the mechanism but not sure about modern digital meters, I have heard they can read reactive. In a domestic setting I don't think power factor is going to have a great impact on cost unlike industry running large inductive motors and such.
 

guineafowl21

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Yes, I’ve heard smart meters can read all forms, so at the click of a button we could be charged extra, possibly for apparent power, which is of course always >= real power, so the power companies will benefit.
 

TheUnicorn

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I have turned our microwave off at the switch for years, it has just become habit. I also (pretty much) never leave the telly on standby and I try to not leave lights on if I'm not in the room. it is not that I am massively environmental, I just don't see any real benifit of leaving things on if they are not in use.
 

Sandyn

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EMC Standard EN/IEC 61000 3-2, ensures the power factor is within requirements. It looks at the harmonic currents generated by equipment. It applies to equipment of up to 16A per phase. I think the latest revision came into force in 2017.
 

ian33a

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I've always left my desktop PC running as I couldn't be bothered to turn it off or hibernate it. I just got used to everything being virtually instantaneous when I wanted it.

This thread got me to rethink what I was doing. I implemented hibernation and measured the time it takes to come out of it. Even including the time to type in my pin it was less than about 10 seconds - hardly a massive drain on my time. Power saving : about 100 watts. So, with electricity costing what it does now, that's a saving.

Also, with moving, I've been gradually packing away stuff that needs to be boxed. We're saving about another 100 watts from stuff that was generally on standby to now being in a box. When we do move, the trick will be to unbox it and not leave it always plugged in.

Put in context though, the big savings have to be in not putting too much water in the kettle and not leaving the oven or grill on any longer than really necessary. The big hit heaters have to be our biggest power drain.
 

Stevekane

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I've always left my desktop PC running as I couldn't be bothered to turn it off or hibernate it. I just got used to everything being virtually instantaneous when I wanted it.

This thread got me to rethink what I was doing. I implemented hibernation and measured the time it takes to come out of it. Even including the time to type in my pin it was less than about 10 seconds - hardly a massive drain on my time. Power saving : about 100 watts. So, with electricity costing what it does now, that's a saving.

Also, with moving, I've been gradually packing away stuff that needs to be boxed. We're saving about another 100 watts from stuff that was generally on standby to now being in a box. When we do move, the trick will be to unbox it and not leave it always plugged in.

Put in context though, the big savings have to be in not putting too much water in the kettle and not leaving the oven or grill on any longer than really necessary. The big hit heaters have to be our biggest power drain.
So is that 200watts per year? Not so long ago we were using 100watt lamps,,thats 100watts consumption per hour in old money I think,,,and whilst Im in agreement with everything being said I still have the feeling that were just tinkering around the edges and a lot of this energy saving hype, like the old “if your paying too much its because your too idle to switch” is to create the impression its somehow our fault energy costs so much when in reality its to do with mismanagement by successive governments over the past 40 years or so,,,a failure to take the hard decisions,,and were now paying the price.
Steve.
 

Spectric

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Another government failure is not introducing a scheme to give incentive to everyone to ditch old style lighting in favour of LED's including industry. Dump all the high bay sodium and discharge type lamps and old flourescent type fittings and the savings would be huge, so rather than trying to keep up with demand it should be reduced. The cost of energy should also be tiered, reward the low users and penalise the high users.
 

Old.bodger

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Real life example of standby power at a constant of 200 w .
cottage in Cumbria. Economy 7 tariff. Two year , recent fixed term. Day unit cost £0.3283 per kwh Night £0.2225 kwh ignore the standing costs - they extract those any way.
7 night hours = 1.4kw (7x200w) at £0.2225 = £0. 31
17 day hours= 3.40kw (17x200w) at £0.3283=£1.11

Total per 24 hrs = £1.42

31 day month =£ 44 unless my logic / maths is wrong.


Here in the South East. Fixed non E7 Tariff due to end Feb 23.
£0.1764 kwh 24 hrs at 200 W = 4.8 kwh
So that will cost £0.85 a day £26.35 a month.

so it varies a lot !
 
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ian33a

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So is that 200watts per year? Not so long ago we were using 100watt lamps,,thats 100watts consumption per hour in old money I think,,,and whilst Im in agreement with everything being said I still have the feeling that were just tinkering around the edges and a lot of this energy saving hype, like the old “if your paying too much its because your too idle to switch” is to create the impression its somehow our fault energy costs so much when in reality its to do with mismanagement by successive governments over the past 40 years or so,,,a failure to take the hard decisions,,and were now paying the price.
Steve.

No, it's 200w average power consumption - so, in five hours, that's a KwH - so the cost is approximately £413 per year (minus the time the items are physically being used).

Even the pump in our modest fish pond is costing us about £100 a year to run now!



Before these price hikes I didn't give this whole thing much thought. With pinched budgets I'm less inclined to line the pockets of the shareholders of energy companies and I'm much more aware that incremental small changes gear up to make a massive difference.
 
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ian33a

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Real life example of standby power at a constant of 200 w .
cottage in Cumbria. Economy 7 tariff. Two year , recent fixed term. Day unit cost £0.3283 per kwh Night £0.2225 kwh ignore the standing costs - they extract those any way.
7 night hours = 1.4kw (7x200w) at £0.2225 = £0. 31
17 day hours= 3.40kw (17x200w) at £0.3283=£1.11

Total per 24 hrs = £1.42

31 day month =£ 44 unless my logic / maths is wrong.


Here in the South East. Fixed non E7 Tariff due to end Feb 23.
£0.1764 kwh 24 hrs at 200 W = 4.8 kwh
So that will cost £0.85 a day £26.35 a month.

so it varies a lot !

Your maths lines up with mine (albeit, I'm now stuck on a higher priced tariff than you are) - and we can almost wave to each other across the Surrey countryside!
 

Stevekane

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No, it's 200w average power consumption - so, in five hours, that's a KwH - so the cost is approximately £413 per year (minus the time the items are physically being used).

Even the pump in our modest fish pond is costing us about £100 a year to run now!



Before these price hikes I didn't give this whole thing much thought. With pinched budgets I'm less inclined to line the pockets of the shareholders of energy companies and I'm much more aware that incremental small changes gear up to make a massive difference.
Im getting very confused with all this,,,are we saying that running the led clock in the micro and telly can cost up to £413 per year? I sure Im misunderstanding something,,,
Steve.
 

guineafowl21

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Im getting very confused with all this,,,are we saying that running the led clock in the micro and telly can cost up to £413 per year? I sure Im misunderstanding something,,,
Steve.
Unlikely, since mine, for example, uses about £2.36 per year idle.

They may have found A microwave that uses £15 a year, but most probably don’t.

I use one of these cheap/cheerful things; quite interesting to see what uses what, and when:
 

ian33a

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Im getting very confused with all this,,,are we saying that running the led clock in the micro and telly can cost up to £413 per year? I sure Im misunderstanding something,,,
Steve.

Much of it comes down to the difference between watts and watt-hour :

All electrical items, even something like a battery wrist watch consume power if they are connected to a power source. The power source has a voltage potential between it's two terminals, in the UK, this is approximately 220v for mains (I'll ignore the difference between AC and DC in this illustration).

If an electrical item is connected between the two power source terminals, this electrical item will introduce a resistance between the two terminals of the power source. The resistance limits the amount of current that can flow from the power source into the electrical item and back out again. The current, in conjunction with the voltage available from the power source defines how much power the electrical item consumes. The circuitry inside the electrical item, often complex, needs a certain amount of current to make the electrical item work. If insufficient current is allowed into the electrical item, it wont work properly.

So, a couple of examples, a battery powered wrist watch requires very little current to operate, just a few millionths of an amp (the unit of current). An electric car requires tens of amps to operate. So, a wrist watch requires a small power source and an electric car requires a large power source.

Now, at any point in time we can measure the power required by our electrical device in watts. Put simplistically, it is the product of voltage and current. So, for my PC, needing 100W, at 220v supply it needs 0.454 Amps of current. This current keeps the microprocessor running, it keeps the memory intact, it drives the graphics card, the sound card and provides power to the various USB ports. The power taken by the PC, and most electrical items, will vary depending upon what we are doing with them at any point in time. With my PC, if I am simply reading email, it isn't taxing the hardware and the power drain is quite low. If I decided to play video games or do something which stresses the PC hard, it takes more current, and thus consumes more power.

When we pay for our electricity, the electricity companies charge us as an accumulated usage. They measure it in Kilo watt hours or KwH. The electricity meter samples the current which each of our houses draws from the national grid at fixed intervals and records the current taken over a period of time. So, in the case of my PC, consuming an average of 100W of power, it would take ten ours to consume 1 KwH of power (100W average over ten hours). If my energy supplier was charging me, say 25p per KwH, my PC would cost me 25p per ten hours. Over a year, there are 876 blocks of 10 hours, so my PC would cost me £206.74 to run.

If I put my PC into standby all year, it would still cost me a bit to run because some power is required to drive the basic system even though most of it is sleeping. When I made the measurement I looked at the delta between it being on and being in sleep mode and it's the delta that I used in the calculation.

My PC is a decent enough illustration as it's fairly average in terms of power consumption.

If I had a 1000W microwave running continuously for a year it would consume 1000W continuously. That's ten times as much as my PC so the mircowave would cost me £2067 for the whole year! Obviously, nobody does that.

The thing is, when the microwave is not heating up my lunch, the clock is running and some simple support circuitry is also monitoring the microwave for safety and sensing when I press some buttons. All of this housekeeping may only be taking a small fraction of an amp of current so, because watts is a product of voltage and current, in standby mode, it may be consuming 1 or 2 or half a dozen watts. So, if it was consuming 5W, it can sit there for 200 hours before it consumes a single KwH and costs me 25p. (it does charge for fractions of Kwh, in case you are wondering)

So, be it mains driven or battery driven, the electronics industry has been put under massive pressure to minimise power usage. Lower power means that batteries need to be recharged (or replaced) less frequently or less power is consumed through our mains sockets.

If we unplug everything when we are not using it, it consumes less power and we are not charged. It is, however, inconvenient (having to reset the microwave clock, for example). So life becomes a balance between consuming (and costing) more power and convenience of usage.

My large OLED TV, as an example, consumes an average of 132W when I'm watching something on it. When I have turned it off with the remote control but not unplugged it, it consumes 0.5W. I would need to leave it in standby for 2000 hours before it cost me a single KwH of energy but I'm not going to turn it off at the wall and have to wait for the damn thing to boot up each and every time I use it so as to save that amount of energy...... this is how modern electronics has been designed to reduce power consumption.

(In case you are wondering - I spent most of my working life in the technology industry in electronic testing).
 

Craig22

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I've studiously avoided going for a smart meter. Part of that is the intensely irritating and various dumbing down adverts with all sorts of very iffy statistics to go for a smart meter (the latest being an Einstein look alike, for heaven's sake), part is no real need to do so because I am perfectly capable of reading the meter, and part is waiting for smart meter technology to stabilize.

Like Ian above, my background and working life has been in various high technology disciplines, largely electronics and optical systems development.

However, faced with a step increase in our energy cost of 86% (and more to come later in the year) I finally cracked and smart meters are about to be installed on 9th May. We're with Octopus by the way, who in the whole spectrum of energy suppliers are a good bunch to deal with.

Craig

PS Smart meters are still not stable. In England they communicate using 2G/3G. The government is phasing these out - in their entirety in 11 years - to make bandwidth room for 5G and (good heavens) 6G. So at some point smart meters will have to be upgraded to cope with a change in comms method.
 

ian33a

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I've avoided smart meters too Craig.

Initially, I didn't trust the energy providers motivation. Later I discovered that most were not compatible with PV systems (which we have). I built a PV dump system to use some of the surplus generated PV to heat water in the water tank. Doing that didn't fill me with confidence that they will work properly with that either. Then, there's the incompatibilities with the older ones if you move from one supplier to another. Doesn't fill me with a good feeling.

Like you, we are now with Octopus. Not through choice, through redirection when Avro popped their clogs. Octopus seem fine. We're in the process of moving, it may happen some day if the chain can all speak with one another :=). I'm hoping to get Octopus at the new place. There's PV there too. I'm hoping to re-install my PV dump there provided I can get the various modules to communicate with one another (the distances and wall thicknesses are larger).

I'm also seriously reconsidering a battery for the PV. I'd discounted the idea before as it didn't make financial sense. With these last price rises I will get my spreadsheets out again.
 

Craig22

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We've liked Octopus, and intend to stay with them. The price delta is not their fault - it is in common across the energy supplier industry. And they have not pushed us in any way to get a smart meter - they leave it to the customer to make a personal decision all on their own.

They will definitely not go pop the same way as Avro and umpteen others. Octpus's main business is financial services UK Investments | Octopus Investments so they have a well funded stable structure.

Craig
 

DRC

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This issue really comes down to building regs which are really outdated. What is required is an electrical system that has circuits with timers so for example all the entertainment devices like the Tv, set top boxes etc are on a radial that turns of at a certain time and comes back on in the morning, again at a preset time.

The other area where energy can be saved is having devices correctly setup, many have power saving modes which mean the device may take longer to power back up but consumes less when not in use, an example is our Freesat box.
I thought some years ago (about 15-16yrs) about this standby issue and went down the road of all my TV's, recorders, HiFi ,aerial amp, and LED lamp transformers are plugged into Home Easy programmed sockets but you may say they (about 6 of them) consume current as well. The answer is, the current consumed is so small when they are in the OFF mode it's almost impossible to measure accurately. I also use this type of socket on other items around my home. The idea of PLC (Programmable Logic Control) controlled home was mooted about 20+ years ago but the take up was so small for the home/domestic market it never got off the ground in a big way. This sort of system can be easily fitted when building new homes so that everything can be programmed and altered and reprogrammed by the home owner. thereby saving energy costs. There is the perfect world and then there is reality.
 

Spectric

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Smart meters are in the same stage of life as we went through with Betamax and VHS recorders, not enough standardisation and it is only the supplier who will benefit from people having these meters fitted, and I suppose the enviroment because they will not require people to travel round to read them occasionaly.

The adverts are misleading, they almost infer that a smart meter will save you energy without any action on your part which is nonsense, again I think they are aimed at people who are not savy enough to take control of their energy usage without some digital display, the ones who leave all the lights on and have been upto now rather carefree, but the only way to reduce consumption is to turn off electrical loads and if you are on bare minimum then unless you sit in the dark and vegetate what else can be done.

I think the issue with smart meters has a lot to do with cost, just like we want the best woodworking machinery for less they need cheap meters due to the potential volume required.

There are also situations where they just don't work due to comunication issues, so maybe rather than just rely on mobile they should have the option to use your broadband router.
 

ian33a

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I thought some years ago (about 15-16yrs) about this standby issue and went down the road of all my TV's, recorders, HiFi ,aerial amp, and LED lamp transformers are plugged into Home Easy programmed sockets but you may say they (about 6 of them) consume current as well. The answer is, the current consumed is so small when they are in the OFF mode it's almost impossible to measure accurately. I also use this type of socket on other items around my home. The idea of PLC (Programmable Logic Control) controlled home was mooted about 20+ years ago but the take up was so small for the home/domestic market it never got off the ground in a big way. This sort of system can be easily fitted when building new homes so that everything can be programmed and altered and reprogrammed by the home owner. thereby saving energy costs. There is the perfect world and then there is reality.

I'd discounted a lot of these systems in the past because the financial outlay didn't stack up against the potential savings. A lot of them are starting to become attractive now that we are in this brave new energy world .

I will certainly be reconsidering them when we move. In part, because our current house has so few power sockets, I've not explored the idea. The new place has an abundance of 13A outlets and it lends itself better to PLC.
 
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