Permanently plugged in mobile chargers - A wasted energy discussion

Permanently plugged in mobile chargers - A wasted energy discussion
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We had several conversations at the VIP day about the load created by plugged in mobile chargers with no mobiles connected, @Transparent if I remember was very vocal on this issue.

Anyway, I plugged my energy monitor into a 13A socket and plugged in an Apple iPhone charger; I left it for ten days. Result 0.00kWh usage PF=1, I have to say I was surprised


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Just stumbled across this topic on my optimising journey - some interesting stuff!

 

Could this be a good use case for your new monitoring equipment@Transparent and @Simon1D ? 


Thanks @Jess_OVO - I think this all dates from before I joined the forum here.
After a quick skim through the comments, I'm prompted to add:

Aside from the very capable Open Energy Monitor kit (@Transparent and I have barely scratched the surface of what it might tell us), I've had one of those 13A mains socket plug-in energy monitor things for years and, early this summer, dug it out and used it to look at the consumption of a few devices. With hindsight, I realise it was this little investigation that made me so interested in the OEM project, and ready to splash out on the OEM Emonpi setup.

The biggest surprise I got, using the simple mains socket power monitor, was our washing machine (a Samsung “ecobubble”). We've always left it on standby (i.e. left switched on at the wall when powered off by touching a button on the control panel), it only uses a cold feed (and so does its own water heating), and it is run most days (but perhaps not every day). I was frankly astonished to discover that standby accounted for over half its energy consumption. On standby, it draws 15W (it is "only" ~5 years old? but therefore predates the EU directive limiting standby power to 1W. [Edit - how wrong could I be: implementation of the directive apparently dates back to 2009 and 2012, and mentions 1 W and 0.5 W respectively. I can’t be bothered to check original sources - perhaps there’s some special exemption for washing machines...) That's 360 Wh per day, about 120 kWh per year, about £20, while the programme we use most turned out to consume 0.335 kWh per cycle.  That's around £20 to actually do all our washing, plus over £20 more to do, well, to do sweet Fanny Adams...
Not any more.
You don't have to be an energy saving obsessive to get the point, and develop the habit of switching it off at the wall when unloading the machine at the end of every cycle.


Next, I monitored our 3 ageing fridges and 1 freezer. Not as efficient as new ones would be but (just about) running well enough to keep food (and beer) cool enough. They draw about 120 W between them, which would account for most of the irreducible minimum electricity consumption to be seen in overnight smart meter data.


In the Emonpi data (a record of demand for electrical power having 10 s resolution in time instead of 30 min) one can see the freezer and fridges all turning on and off, independently of one another, in a more or less random way.

That little 13A mains socket plug-in energy monitor gave me a better insight into what accounts for what, in the way of electricity consumption.

 

Not that I was completely unaware before, or anything ...

Earlier this year, over the course of a few weeks, I replaced the lights. Now they are almost all LEDs with a few compact fluorescent fittings, previously they were almost all fluorescent with a handful of tungsten bulbs and a few LEDs. We are better lit, and the average daily electricity consumption is now 7-8 kWh where previously it was 10 kWh.
It amazes me that merely replacing the bulbs had the effect of reducing our consumption by ~25%, but I've racked my brains and can't come up with any other explanation for what is fairly clear in smart meter data that cover almost 2 years, including the 6 months that have elapsed since I changed those bulbs.

It’s the need to easily generate evidence to back up (or refute) such interpretations that is why I want better presentation of “usage”, a.k.a. consumption than Ovo offers. In particular, I want to see a plot of consumption over arbitrary periods of time but with decent resolution. Talking of which, I need to return to my Python coding. I’m nearly done, @Tim_OVO, honest ...

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I think we ought to keep to different strategies:

A: For monitoring individual appliances

B: For monitoring the whole house

 

A: The plug-in socket energy monitor which @Simon1D mentions will look something like this:

I would recommend buying something like this from a reputable British company such as CPC/Farnell. Unlike Amazon or eBay, the Farnell group has buyers who will be checking the quality of products and ensuring that they comply with relevant safety standards.

These energy meters are designed specifically to monitor an individual domestic appliance wherever it is in the home. Some also allow the appliance to be turned on/off remotely via a dedicated App or a generic ‘smart home system’ such as Alexa or Nest.

 

B: The EmonPi Energy Monitor system being investigated by @Simon1D and I is for looking at the overall electricity usage within the home. It has a static base-station, usually sited close to the consumer unit and Smart Meter. In those locations it’s possible to use current-clamps around individual live wires.

 

You can’t use such a current clamp around a 3-core flex. The current being sent via the Live wire will be cancelled out by that returning on the Neutral! The clamp must be fitted only around the Live.

Moreover, if you wanted that data to be sent back to the EmonPi base station, you’d have to buy a separate EmonTX to transmit it wirelessly.

 

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I’m liking where this is going, people!

 

@Simon1D I was shocked about that washing machine standby running costs. Why on earth does it even need to be on ‘standby’ and using electricity. Something like this should be on or off. I’ll need to locate the plug in my kitchen so we can start turning it off when not in use.

 

OVO Greenlight attempts to help members be informed about this kind of inefficiency or unexpectedly high usage. That’s what the team want it to be used for.  

 

 

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...

@Simon1D I was shocked about that washing machine standby running costs. Why on earth does it even need to be on ‘standby’ and using electricity. Something like this should be on or off. I’ll need to locate the plug in my kitchen so we can start turning it off when not in use.

Shocked definitely. Gobsmacked, even, yes.

Making a measurement is always a good thing to do, think of it as a calibration of one’s knowledge of the world … got to be evidence-based, etc. (I suspect @Transparent would agree).

I didn’t mention it before, but there’s a largish screen tv downstairs that is almost never watched, from one month to the next. It too is on standby - ever ready, at a moment’s notice, to leap to our service. Me? An energy-saving obsessive?? Not entirely, no ;-)

But how much longer can I stand to remain in ignorance of that tv’s standby power consumption? Perhaps not much longer...

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Evidence-based…. absolutely!

There’s lots of extra bits I could do to my house by way of energy efficiency. But I prioritise them because I assess the level of energy loss first! Refitting a poorly-installed window isn’t important if it’s going to cost £500, take 3 days with scaffolding, and have a pay-back time of 100 years!

Since @Simon1D has mentioned his washing machine, let me provide a cautionary note about fridges and freezers.

Contrary to common-sense public opinion, the efficiency ratings provided on the sales labels have nothing to do with the electricity it will consume to keep the box cold.

Efficiency of domestic cooling appliances is related solely to the insulation.

The efficiency ‘score’ between A* to G is calculated by placing a beaker of warm water in the middle of the box, closing the door/lid and then measuring the heat loss over a period of time.

So you can actually buy a B-rated fridge which uses less electricity than an A-rated one of the same size!

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...

let me provide a cautionary note about fridges and freezers.

Contrary to common-sense public opinion, the efficiency ratings provided on the sales labels have nothing to do with the electricity it will consume to keep the box cold.

Efficiency of domestic cooling appliances is related solely to the insulation.

The efficiency ‘score’ between A* to G is calculated by placing a beaker of warm water in the middle of the box, closing the door/lid and then measuring the heat loss over a period of time.

So you can actually buy a B-rated fridge which uses less electricity than an A-rated one of the same size!

Interesting. So that time, many years ago when my fridge failed to cool altogether (it was as if it had lost its coolant - the compressor would run but have no cooling effect at all) ... that no-longer-cooling fridge could be tested for efficiency according to the official definition and it would score essentially the same as when it was new, because the insulation was intact and unchanged?!?

We replaced  it, of course, but I can imagine some semi-technical person thinking they were making an “evidence-based” decision if they were to say “let’s test the old fridge for efficiency, following the official protocol and, if its not good enough, we’ll replace it.”

If I read something like that, I doubt I’d spot the foolishness.

The lunatics have taken over the asylum ...

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The logic behind this situation can be extended further. According to the ‘standard’, the most efficient fridge is one that’s switched off.

Not only is the insulation just as effective…

… but it’s now using no electricity either :hugging:

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If buying a new appliance i would personally stay clear of anything with the old ratings. So anything with A* for example.

The highest rating is now A.

There is a bit about the new rating here

https://www.which.co.uk/news/2021/06/where-have-all-the-a-rated-fridges-and-fridge-freezers-gone/

 

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If buying a new appliance i would personally stay clear of anything with the old ratings. So anything with A* for example.

The highest rating is now A.

There is a bit about the new rating here

https://www.which.co.uk/news/2021/06/where-have-all-the-a-rated-fridges-and-fridge-freezers-gone/

 

Thanks @Jeffus - that’s helpful: at least the Which? test is sensible:

How much energy to keep something cool?

and

How much energy to cool something down?

It’s a great shame that this page (turned up in a general web search just now, not a search specific to the Ovo site):

https://www.ovoenergy.com/guides/energy-guides/energy-efficient-fridges-and-freezers

is dated 01 Feb 2021, just one month before all the ratings that it talks about were superseded.

Action needed. Perhaps @Tim_OVO and/or @Jess_OVO can take this up.

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The new ratings combined with the Which tests should give a reasonable indication of appliances and any anomalies should jump out. Which often do free trials or you might be able to ask around for someone with a subscription. Alternatively manufacturers/retailers often highlight Which best buys. 

As i said on a previous post from personal experience i would also be careful when positioning fridge freezers so they are not too close to hot water pipes, ovens, radiators, very sunny spots etc. if at all possible.

The old ratings were terrible as they were far to easy to meet hence the A* etc. 

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Great spot there, @Simon1D and @Jeffus - and great to hear this page was so highly rated by Google!

 

We’ve passed this one on to the content team for an update. Just as we were talking to them today about how much knowledge and expertise we’ve got here on the Forum too - keep on doing us proud! :thumbsup:

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I was about to write something insightful about leaving a TV on standby. But the story would probably fit better into the Feel Good Friday slot :slight_smile:

 

… which you can now read here

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A while back, I tried to get a rough idea what our electricity consumption was for, hoping to eliminate waste.

I’d fitted LEDs everywhere already.

I found and eliminated the washing machine (15 W on standby, to absolutely no useful purpose whatsoever).

I was already aware of the 3 ancient fridges and 1 ancient freezer (average 120 W in total - needlessly extravagant, and will be replaced with modern and more efficient versions at some point).

But EmonTx tells me there’s more, and I was at a loss to know what it is:

Overnight plot of household electricity demand (W) vs. time

I’ve no proof, but that looks like the one of the fridges (or the freezer) coming on, running for just over 20 minutes then staying off for another 80 minutes or so, regular as clockwork, all the time. The others are doing similar things, in their own time and making similar contributions to the demand-time plot.

Seeing this graph reminds me that I did spend a few minutes wandering round this morning, smart meter IHD in hand, turning things off as I found them, hoping that something would have a noticeable effect, but nothing did.

Unconnected to this, I happened to come across a remark in some DIY forum this evening,

“50 W? That’s not very much for a home intruder alarm system”.

Wait. What? 50 W?? We’ve got an alarm. Came with the house when we moved in. Previous owner said they gave up using it - the annual contract cost far more than the reduction it got them in the insurance premium. We’d never had an alarm before and didn’t give it another thought. I hadn’t even learned where the control panel was.

But I soon found it and (temporarily) prised open the fuse holder, thereby disconnecting the mains supply (it has a battery backup that lasts a few hours at least). Sure enough, the demand dropped (roughly) 50 W when the fuse was removed, and went back up by ~ 50W when the fuse was put back.

Never mind the cost of an annual contract, that’s over £70 in electricity alone (and ~15 % of our total consumption, for heaven’s sake). I’m not promising to turn it off because it’s doing something that is, arguably, useful. But at least I now know what it’s costing me and I admit that I had absolutely no idea before now.

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And just where is 50w being used in a home alarm system which isn’t operating its sounder?! :scream:

  • Trickle-charging a battery?
  • Blinking indicators?
  • Sending a amp through the anti-tamper loop when a few mA would do?

There’s an obvious market here for a 16-yr-old geek to create a new design using an Arduino and license it to the major companies!

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my money's on the trickle charging. I haven't tried opening mine up, but the YouTube video I saw showed what looks like quite a chunky lead acid battery...

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Would it compromise the insurance certification if that were changed to a Li-ion battery and charger module at equivalent Amp/Hr rating, I wonder?

Here’s the electronics charge module available for less than £2 from AliExpress

 

You need to add four LiMNC or LiFePO4 cells of whatever capacity you want.

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It's true there is a little sticker that I would break to get inside, but I don't have any kind of maintenance or monitoring contract, and don't claim to have an alarm on my insurance policy, so I don't see a problem. Your suggested little Arduino project (it would be my first) could keep those LEDs, on the external box, flashing for a lot less than £70 a year.

Reminds me - I've never heard the alarm do anything, I ought to check that those LEDs are actually flashing, otherwise the whole thing is pointless.

BW and thanks, @Transparent :-)

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My EmonPi monitor module is different to yours @Simon1D , but it has an Arduino Mega-328P processor on it. Your one may have the same.

A Mega is greatly more powerful than would theoretically be required for either energy monitoring or a home alarm system. But it does have more serial ports (4), internal clock/timers and several pins which can receive interrupts.

It’s those features which tend to make one Arduino version preferable to another. The cost differences are pretty insignificant.

https://hexbee.blogspot.com/

 

The main difficulty I can foresee here with using these devices and modules to reduce household energy consumption is that @Tim_OVO and @Jess_OVO now haven’t a clue what we’re discussing :confounded:

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A fantastic post, Simon. Very good investigating, can you help us understand what EmonTx is? 

 

This is something I am interested in, as we have (what we think is) a security alarm in our rented house. We don’t use it, but it has a control panel. When power to the house is disconnected, this control panel goes through some kind of reset, and at some random point, the loudest alarm goes off in our hallway. We have a 4 digit code which we put into the control panel, and the alarm stops, until the next power disconnection. An absurd state of affairs, which we’ve accepted for years. 

 

You’ve just given me another reason to get this ripped out. High electricity running costs. 

 

Can I ask, why don’t you get this disconnected? You don’t use it, it costs you money to power. But that wasn’t one of your stated options, @Simon1D

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I have an advantage, in that the previous owners left the user’s manual for the system. Although, tbh, that doesn’t say any more than I found in a youtube video.

Our (and presumably your) options are

  • pay a specialist to decommission and remove the system, “properly”. Probably not cheap.
  • Or:
    • remove that fuse (for electrical safety)
    • open the box, disconnect the battery
    • at this point, the alarm will sound, but anti-nuisance laws mean that it shouldn’t sound for more than 20 minutes (and in any case, whatever it’s running off now the battery has been removed will die before long)

At this point, all being well, you might need do no more.

I was deliberately vague about disconnecting our own. I think the reasoning is that having a box on the exterior wall with LEDs that blink, modestly, is supposed to deter intruders. I’ve even read that this might be true. I wouldn’t know, tbh, and virtually all the info I saw online was security specialist firms saying that intruder alarms are worth having.

They would say that wouldn’t they

etc.

If @Transparent’s suggestion to replace the lead acid battery with a lithium ion one leads to dramatically lower running costs, I would probably make that change and leave it in place and functional. But otherwise, as you seem to agree, £70 per year seems like a lot to pay for questionable benefit.

 

I feel sure you will recognise this thread on EmonTx/Emoncms

:-)

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@Tim_OVO  - EmonTX is one of the boxes which @Simon1D introduced us to on the Energy Monitoring topic. As his sensors are remote from the main data-logger, he has a transmitter (Tx) which collects the data and then sends it.

I, otoh, will be positioning all of the electronics in the same enclosure, near to the sensors. I therefore have an eMonPi module (shield) which connects to the Raspberry Pi controller using a physical cable.

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@Tim_OVO  - EmonTX is one of the boxes which @Simon1D introduced us to on the Energy Monitoring topic. As his sensors are remote from the main data-logger, he has a transmitter (Tx) which collects the data and then sends it.

I, otoh, will be positioning all of the electronics in the same enclosure, near to the sensors. I therefore have an eMonPi module (shield) which connects to the Raspberry Pi controller using a physical cable.

I detect a certain uncompromising air about your response, @Transparent ... I can be such a softie, myself ;-)

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I know someone who moved into a house in Bristol which had a monitored alarm system installed. He wanted to disable it, but of course, the external box went off at full volume so he had to stop.

As he didn’t own a ladder, he employed a local builder to come and remove the external box for a modest sum.

The man duly arrived, opened the front bedroom window, leaned out as far as he could whilst holding onto the frame, and swung a hammer at the box. :scream:

It fell to the ground in less than a second and smashed to pieces.

He pocketed £20 :hugging:

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