[Closed] Electricity use has jumped - what/how to check / monitor recommendations

Are going from meter reading to meter reading or have there been estimates used in your billing? If estimates have been used then this could just be a correction.

Pretty sure it's reading to reading.

You don’t have underfloor heating that might have been switched on do you?

Nope. We have an electric immersion on the water tank, but that only runs when the solar is pumping power back into the grid (it's on an iSolar thing)

We have an electric immersion on the water tank, but that only runs when the solar is pumping power back into the grid (it’s on an iSolar thing)

The iSolar thing will have a clamp which goes around your electricity supply to measure export from the panels and then divert that power to your immersion heater.

It's not that obvious which way around they go and it's possible that it's been clipped on backwards after your consumer unit change, which means that your immersion heater runs when you're actually drawing power from the grid.

This is the first thing I'd check (the CT clamp may be next to your main fuse, or in the consumer unit, or on the wiring from your panels somewhere).

90Kwh/month seems insanely low!!

which means that your immersion heater runs when you’re actually drawing power from the grid.

This is the first thing I’d check

This was a thought I'd had, and I have checked it quickly, and it's only running when the sun's shining (today is a good example, it's kicking in when the sun comes out and not when the clouds come over). I'll double check the clamp though, you never know, but I don't think he even touched it given where it is physically in relation to the consumer unit.

90Kwh/month seems insanely low!!

I may have the number wrong, but we've used a lot more this month than last month whatever.

Misread the meter. I did this last time and woke up to a £2k bill this month. All resolved now and a smart meter getting fitted next month.

Misread the meter.

Nope, we've both checked and rechecked. Of course, it could have been a misread on a previous reading I suppose.

I may have the number wrong, but we’ve used a lot more this month than last month whatever.

it's certainly strange!
We're down to about 6kwh/day (over the last 10 days) and that's with solar PV heating the water so no boiler pumps running.

Take daily readings - preferably last thing at night and first thing in the morning to see where the usage is during each 24hrs.
If you have a 4Kw solar array you should be using very little between 9am-6pm
I found that our house uses nearly 3Kwh overnight on "stuff"!!
(big fridge freezer, mesh wifi, multiple sonos, etc.)

I'm not sure that all solar immersion diverters are equal and there is a possibility of power being imported - but not to that level.

90 kwh per month on elec sounds very low .

300kwh per month is about what we use per month - 3 people - gas CH/Boiler - so elec is only used to run lights (all led) ,tv,fridge, computer, wifi, dishwasher etc

Take daily readings – preferably last thing at night and first thing in the morning to see where the usage is during each 24hrs.

Yeah, we're going to start doing that. And, on that subject, any recommendations for usage monitors in the absence of a smart meter (and we've contacted the electricity company about getting a smart meter)? I was looking at stuff like this:

https://www.ebay.co.uk/itm/203964182453?hash=item2f7d366fb5:g:6w0AAOSwBBtii7yM

Try turning everything off and check meter is not moving.

Also hourly consumption profile if poss, should id the culprit.

My immediate thought was immersion, but you've solar so would it be possible that the meter is reporting energy going *out* to the grid as usage?

Anyway, smart meters let you see minute-by-minute usage which is great for identifying power sinks, but there's usually quite a waiting list for those. However, traditional clamp-based monitors are fairly cheap and just as useful.

We used to have one of these https://efergy.com/elite-classic: clamp around the main cable going into the consumer unit, and then the monitor connects wirelessly and shows your current usage. You can then see how much is being used, turn off entire circuits in the to work out where the problem is, etc. Although I will say you can get obsessed with reducing the 'idle' usage...

As you've solar it's probably worth either investing in a better model than the Classic which can handle solar readings too and show you charts over time, or see if your provider can get a proper smart meter installed quickly.

Right, I've just checked the numbers with MrsIHN. In our previous 'worst' month, so depths of winter, solar doing sod all, lights on, oil heater on in office, we used 300kWh. Last month, which saw the solar kicking in reasonably, no oil heater use, and we were actually away for a week, we used 1200kWh. I mean, WTAF?

I've double-checked the iSolar immersion stuff, and it's definitely only kicking in when the sun's out.

Is there any way a consumer unit swap could have led to this? I'm going to get the fella back, if only to try and work out what's drawing what, but I'd like to be slightly forearmed with some knowledge of any mistakes he might have made.

Fault on the solar?

I'm wondering if your meter is faulty and counting your solar export as import. You should have a second meter for your solar generation - what's that saying?

7kW average (which is what 1200kWh in the space of a week gives you) should be sufficient to make the supply cable into your meter noticeably warm to the touch.

Is the meter showing how much you have exported rather than imported (just a wild guess..)?

Fuse board change won’t make a difference, there’s nothing in them that has a current usage. Unless you had AFDDs fitted as the processor in them uses about 1 watt a day. In domestic settings the biggest draw is if you’re trying to change the temperature of something, so check the solar tail clamp, there will be a direction arrow on it, and if you can turn the immersion off for a bit

(which is what 1200kWh in the space of a week gives you)

Sorry, just to be clear, the 300kWh/1200kWh figurers are monthly.

You should have a second meter for your solar generation – what’s that saying?

We have, I'll check

Something's very wrong there!!

Is there any way a consumer unit swap could have led to this?

Possibly but I've no idea what!

When the solar was installed at our other place the moron wired it so that the solar generation was fed into the incoming side of the meter (rather than into the CU) .... so we were paying for electricity that WE had produce ourselves!!

This is not the case with yours as your diverter wouldn't be kicking in - it would always be waiting for enough generation from the panels.

I’m wondering if your meter is faulty and counting your solar export as import.

Follow the cable from the inverter - it should go either into the CU or into the 'inside' of the meter, not the 'outside'.
If the meter is digital it should be intermittently showing a 'rEd' message when there is power being exported to the grid. This can be checked by switching off the immersion while it's sunny and watching the meter.

if it's not showing the message when you're def generating more than is being used then the meter is faulty.

Do you have neighbours 'attached'?

Sounds like your export is getting tallied on the meter as import (no, I don't know how either :D)

The easiest way to check this I can think of is to watch your meter on a sunny day, make sure you're only running a base load in the house (no washing machines, dishwashers, ovens running). Watch the meter for a few minutes so you can monitor how quickly the tenths, hundredths etc are racking up then isolate the solar system (no, not that one) and see if it stops.

If the meter is digital it should be intermittently showing a ‘rEd’ message when there is power being exported to the grid.

It is showing that message

Follow the cable from the inverter – it should go either into the CU or into the ‘inside’ of the meter, not the ‘outside’.

I'll double check this, but don't believe any of it was touched during the CU swap (and the rEd message suggests it's all the right way around anyway, doesn't it?)

Do you have neighbours ‘attached’?

We do, in an old pair of houses, with possibly some interesting wiring. We've got a nagging feeling that maybe the sparky reconnected an old circuit that was going next door or something?

Watch the meter for a few minutes so you can monitor how quickly the tenths, hundredths etc are racking up then isolate the solar system (no, not that one) and see if it stops.

Irritatingly, it only shows whole units, but yeah, this could be something to try

Is the meter showing how much you have exported rather than imported (just a wild guess..)?

Rockhopper makes a very good point! Difference between import and export might be as little as an arrow or the letters I/E.

(and the rEd message suggests it’s all the right way around anyway, doesn’t it?)

Yes it does.
rEd mean 'reverse energy detected' - so the meter's working fine.

Is the meter showing how much you have exported rather than imported (just a wild guess..)?

It's a dumb meter so it will only show power in one direction. So the meter near the CU will show the imported power and the separate meter near the inverter will show the total generated (not exported... because how would it know how much of your own generation you've used?!)

Right, so then, after logging all the previous readings and dates into a spreadsheet and looking at the pattern of usage, we think what's happened is that MrsIHN possibly misread/mistyped a previous reading, so it was 1000kWh lower than it should have been and that reading was for a 3 month period. The latest one is correct, and is only a month after the previous one, so that 'missing' 1000kWh is all showing in this month. We're going to keep monitoring to make sure, but panic averted.

No help at all on this but interested to see the outcome....

... as usual, human error!

(although it does show you just how much you really are using)

I've learnt that there are clip on smart meters.
Why did no one tell me before?

I’ve learnt that there are clip on smart meters.
Why did no one tell me before?

They are not very good, I had one once and couldn't get it to work at all.

Interested in this, we've just built a new house with 6.4kw solar array, ashp, I work from home in Separate office, lots of clothes washing etc, currently at 3865kw from start of year!

No help at all on this but interested to see the outcome….

Spoiler alert - he threw the wife under the bus, he didn't read the meter, she did and in fact he didn't even know she was reading it and if he had known she was reading it then of course he'd of put a stop to it and she must of borrowed his phone to take the pictures of the meter because he doesn't even know where the meter is or what it does and is at a loss as to how the photos of something he doesn't recognise got on his phone. 🙂

It's like you were there 🙂

Well, the plot thickens...

We're now checking the meter fairly obsessively, and overnight, from about ten last night to half six this morning, we used 12kWh. That seems pretty nuts, doesn't it? We were in bed the whole time.

We're going to start process-of-eliminating what might be using it, but I have a question about the solar panels. I'm aware, from looking at solar for the campervan, that there can be an issue where the panels actually draw power when it's dark, but I assume that on a domestic array this would be pretty rare unless somethings gone very wrong? I'm going to isolate them overnight tonight anyway, just to see, but I think that's clutching at straws, right?

We’re now checking the meter fairly obsessively, and overnight, from about ten last night to half six this morning, we used 12kWh. That seems pretty nuts, doesn’t it? We were in bed the whole time.

I have not heard of that potential fault with solar panels - it seems very unlikely.

Otherwise, the only normal way to consume that amount of electricity would be electric heating. As suggested above - do you have any underfloor heating or an electric towel rail?

As suggested above – do you have any underfloor heating or an electric towel rail?

There is a panel heater in a little hallway, that's really only there to stave off damp, comes on when the temp hits 11deg, goes off at 17deg. It's only rated at 400W though, so even if it was running all day that's only [maths...] 9.6kWh.

We’re now checking the meter fairly obsessively, and overnight, from about ten last night to half six this morning, we used 12kWh. That seems pretty nuts, doesn’t it?

Yes it does!
Our house used 2.2Kwh between 11pm and 8am.
That's running a fairly large fridge freezer, mesh wifi, 2 x TV on standby, 7 sonos speakers, a hardware firewall, 3 x Raspberry Pi's, the Solar PV inverter my PC in sleep mode and a smallish UPS.

I’m aware, from looking at solar for the campervan, that there can be an issue where the panels actually draw power when it’s dark

Pretty positive that there's a thing to stop this built into the inverter.

I’m going to isolate them overnight tonight anyway, just to see, but I think that’s clutching at straws, right?

Probably but it's certainly worth isolating the PV (there should be a big isolator near the inverter) just to eliminate it.
Switch off the immersion overnight also.

Just a thought..... your Solar diverter doesn't have the option for an automatic 'boost' does it?
(My Immersun does - I can set it to boost the hot water at a certain time)

As suggested above – do you have any underfloor heating or an electric towel rail?

A towel rail will only draw about 400w or less. 10sqm of electric underfloor is about 1kw I think but if it was on all night you'd certainly know about it when you walked on it!

IHN: looked in the loft recently?!

lots of stuf runs overnight, and most is not switxhed off.

fridge / freezer
TV
PVR
Microwave
Internet router
mesh wifi points
some radios still draw power when not running
alarm clocks
house alarm
trhe clock in the cooker

not sure that any of those would be massive though...

Do you have any outdoor circuits? Those would be the easiest for neighbours to tap in to.

Either way, it sound like you might want to switch off circuits one by one to help identify the source.

your Solar diverter doesn’t have the option for an automatic ‘boost’ does it?

Possibly, I'll check, although I don't think it's running at night as the airing cupboard is next to the bed/my head, and I hear the fan on the unit when it kicks in.

We’re now checking the meter fairly obsessively, and overnight, from about ten last night to half six this morning, we used 12kWh. That seems pretty nuts, doesn’t it? We were in bed the whole time.

yeah, thats a lot, we used 1.6kw between midnight at 7am last night

Immersion heater on a timer?

Bought an electric car and forgotten about it? 🙂 You’d be surprised how many people don’t expect their electricity consumption to go up with one…

Bought an electric car and forgotten about it?

I sometimes forget that I've already bought milk - but I'm pretty sure I'd remember buying a car 🙂

Bought an electric car and forgotten about it?

Of course! *slaps head* 😉

Check those ceiling mounted pull switches for showers and see if it gets hot. They can wear out and short and happily sit there burning hot for months then maybe burn your house down

Check those ceiling mounted pull switches for showers and see if it gets hot. They can wear out and short and happily sit there burning hot for months then maybe burn your house down

Cheers, but don't have any electric showers.

Just a thought, do you know what type of earthing system you’ve got? It should be noted on the paperwork the electrician gave you when the fuse board was changed

I'm chasing him for the paperwork, but he did install a new earthing rod as he couldn't find the old one (as I say, old house, shared supply with next door, interesting wiring...). Why's that?

I thought you’d say Earth rod (TT) system.
There’s potential You could have a fault that’s sending current down to Earth through the rod. It’s unlikely to be this if everything in the house is rcd protected, but if the electrician has ballsed it up then it’s a possibility. Only seen it once before on an old installation but that was sending around 24A to Earth off a 30A rewireable fused socket circuit fault. Their electricity bill dropped a fair bit after it was sorted!

Hmmmm.... Is there any way I could check that myself?

I strongly suspect your grid connection is not configured correctly and therefore 'backfeeding' your solar panels, this will convert the electrical energy into solar energy and reheat the sun.
Hope this helps.

I strongly suspect your grid connection is not configured correctly and therefore ‘backfeeding’ your solar panels,

Yeah, this is a thought/concern. We're going to isolate the panels tonight and see if that makes a difference.

Should we isolate the panels, or the panels and the invertor? It goes panels -> isolator -> inverter -> isolator -> consumer unit

At the AC isolator the consumer unit and the inverter - this would take the inverter out of the equation.

If power was being back fed the I would also expect your generation meter to be displaying 'rEd' all night as the power would be flowing the wrong way.

Surely you can just flip the breaker on the panels when they are producing and watch what the meter does: speed up, no change or slow down.

..... deleted for being daft.

Surely you can just flip the breaker on the panels when they are producing and watch what the meter does: speed up, no change or slow down.

eh?

Yeah, that confused me too.

He's referring to the old rotary type but even newer meters should have a blinking light that increases/decreases frequency with consumption. The theory being it should "speed up" or blink more often when you turn the panels off during the day.

To test the earth rod theory I'd turn the consumer unit off, if your meter is still drawing then something between the meter and CU is borked. Otherwise it's one circuit at a time.

should have a blinking light that increases/decreases frequency with consumption.

Aaaaah, that's what that light is...

To test the earth rod theory I’d turn the consumer unit off, if your meter is still drawing then something between the meter and CU is borked.

Right, just done that, and gave it a good thirty seconds and there was no flashing from the little red light on the meter, so I assume no power being drawn.

The theory being it should “speed up” or blink more often when you turn the panels off during the day.

Yes but all that's going to tell you is whether the panels are working or not - which is not the issue here.

If it’s going to Earth then it will be from a individual circuit so switching the whole board off won’t help. Maybe a simple test, assuming you don’t want to disconnect the cable from the rod and touch the end (really, don’t do that!) is if you have a smart meter with a tail clamp you could move that to the Earth cable between the board and rod and see if the usage value changes over the period of a couple of hours, if it’s not that then the reading won’t change

from about ten last night to half six this morning, we used 12kWh

12kWh divided by 8 hrs is 1.5kW. So we’re looking for a big load. That’s about half a kettle.

Instead of waiting and reading the meter you need to sit down and look at the live consumption. Easiest way with what you have is timing the gap between blinks of the light. Most meters blink 1000 times per kWh. Labelled as 1000imp/kWh. So at 1.5 kw it’ll be blinking 1500 times an hour. That’s a blink every 1500/3600 0.4s. A more normal rate would be every few seconds when there’s no big appliances on. Turn everything off. Then turn mcbs on in turn until you get the fast rate.

I strongly suspect your grid connection is not configured correctly and therefore ‘backfeeding’ your solar panels,

That would be very impressive as there is an inverter in the way which takes DC on one side and puts out AC on the other side. It only works one way....

Labelled as 1000imp/kWh.

Yep, that's what it says

A more normal rate would be every few seconds when there’s no big appliances on.

Yep, that's what it's doing. And double checked whilst boiling the kettle, and it blinked much faster then.

Maybe I need to check what it's doing in the middle of the night, I'm normally up at some point to have a pee...

Out of interest, how should it blink when we're exporting to the grid from the solar, will it not blink at all?

That would be very impressive as there is an inverter in the way which takes DC on one side and puts out AC on the other side. It only works one way….

What if (and I'm grasping here) there was a problem with the invertor, could it be drawing power from the grid and then just losing it as heat? It's in an unheated draughty stable, so it's not like we'd notice the room warming up.

**EDIT - although I assume it would be fairly warm to the touch if this was happening

Yes but all that’s going to tell you is whether the panels are working or not – which is not the issue here.

I was going with if it slowed down then something could be awry with the panel connection. It's an easy thing to troubleshoot so why not?

If it’s going to Earth then it will be from a individual circuit so switching the whole board off won’t help.

But it will tell you if the meter continues to run. Again, easy to troubleshoot.

Turn everything off. Then turn mcbs on in turn until you get the fast rate.

Yup, now this. Once you have the circuit turn individual sockets/appliances off, if everything is off then you have a leech.

What if (and I’m grasping here) there was a problem with the invertor, could it be drawing power from the grid and then just losing it as heat? It’s in an unheated draughty stable, so it’s not like we’d notice the room warming up.

At 1.5 kW continuous draw I'd have expected it to have burst into flames some time ago.

Have you thought about getting an electrician in? Someone who can stick a clamp on each circuit in turn etc and start narrowing down the problem....

@IHN is it drawing at the same time each night? Still wondering if it's connected to a neighbours heating circuit or such.

At 1.5 kW continuous draw I’d have expected it to have burst into flames some time ago.

Yep, fair enough. As I said, grasping...

Have you thought about getting an electrician in?

Yep, definitely, and if we can't find anything doing obvious checks then we will. Thing is, if it was happening in the day it would be much simpler, for them and us, but it seems like it's happening at night, and I doubt any sparky wants to be around at 3am...

@IHN is it drawing at the same time each night?

Don't know, last night was the first night we measured. Plan tonight is to isolate the solar array and see if that makes a difference. I get that it probably won't, but at least it can be crossed off. It will also be interesting to spot-check the blink rate on the meter when we're not using anything.

but it seems like it’s happening at night,

You don't have any of the old 500W PIR lights which are getting stuck on all night?

The old Halogen ones ate current for breakfast....

You don’t have any of the old 500W PIR lights which are getting stuck on all night?

We have PIRs, but they're all LED (I think) and all go off pretty quickly. Something to check though. Would a blown one still draw? There's a really old one, that never comes on and I assumed was bust, right up on the eaves at the back.

Would a blown one still draw? There’s a really old one, that never comes on and I assumed was bust, right up on the eaves at the back.

Unlikely - they normally fail by overheating and either the bulb dies or the holder fractures and the connection is lost.

This is what I would do.

Tonight, switch off half the circuits (maybe not the fridge / freezer). That will narrow it down to half tomorrow morning (either no current drawn and therefore the problem is likely in one you switched off, or current drawn and it's likely on one left on).

Then the next night, switch off half of the 'guilty half' from the first night.

Repeat until you find the circuit which causes the extra load or you've eliminated them all.

My quick dumb theory is the phantom load is always there but during the day the solar is supplying it. You notice it at night. Quick to test, disconnect the solar - does the load increase?

Out of interest, how should it blink when we’re exporting to the grid from the solar, will it not blink at all?

I can't remember, but don't forget that it will display rEd intermittently when exporting.

Does the range cooker have one of those plate warmer compartments? We had one years ago that was operated with a cylindrical push switch. There was no light to warn us if was on or off & they don’t give out enough heat to notice if your walking past. Ours got left on loads.

Right, well, after a bit of experimentation last night, we've found the culprit!

With the solar isolated, and just a 'base' load of telly boxes, router, stuff on standby etc, the blinky LED on the meter was flashing about once every three seconds. Quick maths (thanks Goldfish) got that to 20 times a minute => 1200 times an hour => 1.2kWh. That's seems quite a lot for what (we thought) was on, but fits what we've been seeing usage wise.

With a bit of structured circuit turn-on-and-offing, we discovered that none of the circuits in the house (and there's only four of them - upstairs lighting, downstairs lighting, sockets, cooker) made any difference. However, when we isolated the feed to the annexe, the flashing dropped to about once every 20 seconds, so 3per min => 180ph => 180w, seems reasonable for the 'base' stuff.

So, out to the annexe, which has it's own 'sub' CU. Circuit switching found the culprit was on the socket spur in the stables. The excitement mounts....

Out in the stable, there are four things plugged in, each on a switched socket. I switched them each off in turn.

Was it the freezer?

...

No

...

Was it the extension lead to the, er, extension lead (I know, I know)

...

No

...

Was it the controller unit to the water softener?

...

No

...

It was none of these things. It was the last socket, turning that off dropped the flashy rate right back down.

So, what's plugged in to the last socket..?
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...are you on the edge of your seat yet?

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The thing using up all the juice, is...

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*Masterchef-style dramatic pause*

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The pump for the borehole. It's running 24/7, and costing us, basically, a fiver a day...

I'm going to call the people now to come and take a look to see what the problem is, but the kind if annoying thing is that we're away next week but we can't switch it off as it supplies next door too.

Still, we've found the source of the problem, in no small part thanks to the advice on here, so thank all for your help.

have a quick look at this, it might help you pin point the problem with the pump quicker

https://www.northridgepumps.com/article-204_borehole-pump-troubleshooting-guide

I’m going to call the people now to come and take a look to see what the problem is, but the kind if annoying thing is that we’re away next week but we can’t switch it off as it supplies next door too.

Ask them to power it for the week when you're away!

They can just run an extension lead out to it.....