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unaccounted for kw house usage


ollie
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hi all self build last year, always thought power usage was a tiny bit on the high side.

 

i'm hoping someone brighter than me can track down where my missing kw's are going!

 

went on holiday 

so house was for idle for 10 days - house used 8.1 kw/h a day 

 

1 day usage of things that were on when we were away

 

asph used 2kwh 

sewage treatment plant - roughly 0.8kwh
mvhr - 1.5 kwh

fridge - 1kwh

(we share a bore hole with neighbour who would have been drawing water but i've been told that borehole pumps use barely any power)

 

thats 5.5kwh 

 

wheres roughly 2.5 kwh going , any ideas?

 

thanks in advance

 

ps not sure its relevant but meter is at boundary and we have a 60m 35mm armoured cable into the houses CU

 


 

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10 hours ago, ProDave said:

And what was left on standby?  Televisions, computers, broadband router, set top boxes, Fridge / freezer left on?  Or was everything unplugged?

 

 

Hi Dave

no everything was left plugged in so router was on , playstation on standby , fridge was running (but i accounted for that in my calculations) , tv on standby, alexa on  - could things on standby really amount to 2.5 kwh a day? 

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42 minutes ago, ollie said:

Hi Dave

no everything was left plugged in so router was on , playstation on standby , fridge was running (but i accounted for that in my calculations) , tv on standby, alexa on  - could things on standby really amount to 2.5 kwh a day? 

 

2.5 kWh per day is only 204 W ie 0.2kW, so that is quite possible.

 

In old money it is 2 lightbulbs.

 

If you put a 25% tolerance on your guesses, that could be half of it.

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You could buy an energy monitor to track usage over time and analyze spikes, day vs night and usage in 5 minute segments via a CT clamp on your mains supply. There are some that can identify specific loads allowing you to tag them to bring unknown ones to the fore, although they aren't always accurate. 

One approach would be to power everything down, unplug everything, turn off fuse to ASHP, and see what the background load is and start looking out for that 200w load. Unless it only kicks in at particular times of the day at least you can rule out a lot. 

It's like the phantom load in a car, the lightbulb in the boot was always on when the boot was closed, some old houses kept a light bulb in the attic on to add a bit of heat for the water tank or link in a thermostat with a heater. There are probably many more wierder examples. My friend lives in a semi and the neighbour has a plug that draws off his CU ! 

You can get plug in energy meters (go into 3 pin plug, appliance got into that) but that's only useful for more accurately gauging particular outlet usage and raising awareness in the family of what leaving a TV on standby can drain, some are much worse than others. Could add data to your search though and a good starting point. 

There are systems you can add to your consumer unit to measure each circuit but once you can measure the whole house load and everything is turned off, you can then flip the breaker/fuse of each circuit to narrow down which one the 200w is coming from, a socket or light circuit etc. If it's that visible. 

Then it's elementary dear Watson! Happy Hunting! 

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Why isn't your solar PV offsetting this? Even 4x 300w panels would put a big dent in your annual reliance on the grid. Obviously a trick question, but you get my point :) 

My friend fitted 4x 250w panels to his house ( used panels which he recovered from a new installation so given to him for free ) and the electricity they're producing ( still! ) is significant, for what they are 'on paper'.

Have you considered fitting even a 'token' PV array?

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21 minutes ago, mike2016 said:

You could buy an energy monitor to track usage over time and analyze spikes, day vs night and usage in 5 minute segments via a CT clamp on your mains supply. There are some that can identify specific loads allowing you to tag them to bring unknown ones to the fore, although they aren't always accurate. 

One approach would be to power everything down, unplug everything, turn off fuse to ASHP, and see what the background load is and start looking out for that 200w load. Unless it only kicks in at particular times of the day at least you can rule out a lot. 

It's like the phantom load in a car, the lightbulb in the boot was always on when the boot was closed, some old houses kept a light bulb in the attic on to add a bit of heat for the water tank or link in a thermostat with a heater. There are probably many more wierder examples. My friend lives in a semi and the neighbour has a plug that draws off his CU ! 

You can get plug in energy meters (go into 3 pin plug, appliance got into that) but that's only useful for more accurately gauging particular outlet usage and raising awareness in the family of what leaving a TV on standby can drain, some are much worse than others. Could add data to your search though and a good starting point. 

There are systems you can add to your consumer unit to measure each circuit but once you can measure the whole house load and everything is turned off, you can then flip the breaker/fuse of each circuit to narrow down which one the 200w is coming from, a socket or light circuit etc. If it's that visible. 

Then it's elementary dear Watson! Happy Hunting! 

hi Mike, thanks for your lengthly reply much appreciated 

 

yep definitely thought about  CT clamp on mains supply to get a good overview of whats going on 

 

- our meter is 60m from the house in a metal kiosk - with a 35mm cable coming into the CU in the house - i was advised to get one of these https://www.amazon.co.uk/geo-Minim-Energy-Monitor-Self-Installed/dp/B00JIMQP6Y/ref=sr_1_5?crid=11D86DIKH87HP&dchild=1&keywords=ct+clamp+energy+monitor&qid=1633685046&sprefix=ct+clamp+e%2Caps%2C169&sr=8-5

but i don't think the clamp will fit over a 35mm cable as its designed for 'standard' cables - do you know of anything that would work?

 

- also thought about using the IHD provided by our smart meter but this doesn't work due to the distance from house to smart meter (they never even set it up!) i have just noticed having going down there that my smart meter does have the led flashing light so i could potentially get a energy monitor that works off the led blink but then i still have the issue its 60m from the house!

 

any thoughts very welcome!

 

thanks

O

 

 

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1 hour ago, Nickfromwales said:

Why isn't your solar PV offsetting this? Even 4x 300w panels would put a big dent in your annual reliance on the grid. Obviously a trick question, but you get my point :) 

My friend fitted 4x 250w panels to his house ( used panels which he recovered from a new installation so given to him for free ) and the electricity they're producing ( still! ) is significant, for what they are 'on paper'.

Have you considered fitting even a 'token' PV array?

 

hi Nick - thanks for your reply yep solar definitely on my radar but very much so now due to electricity price hike - its a capital investment essentially isn't it.

 

Is there a 101 you can point me in the direction of as i know nothing about them - ie is there government grants a bit like the RHI I get from my ashp , who are reputable installers etc

 

thanks

O

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1 hour ago, ollie said:

- our meter is 60m from the house in a metal kiosk - with a 35mm cable coming into the CU in the house - i was advised to get one of these https://www.amazon.co.uk/geo-Minim-Energy-Monitor-Self-Installed/dp/B00JIMQP6Y/ref=sr_1_5?crid=11D86DIKH87HP&dchild=1&keywords=ct+clamp+energy+monitor&qid=1633685046&sprefix=ct+clamp+e%2Caps%2C169&sr=8-5

but i don't think the clamp will fit over a 35mm cable as its designed for 'standard' cables - do you know of anything that would work?

 

The ct clamp only needs to go over the live tail or similar, according to the TLC website the difference in diameter between 25mm and 35mm double insulated tails is 1mm (11mm v 12mm)

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10 minutes ago, ollie said:

 

hi Nick - thanks for your reply yep solar definitely on my radar but very much so now due to electricity price hike - its a capital investment essentially isn't it.

 

Is there a 101 you can point me in the direction of as i know nothing about them - ie is there government grants a bit like the RHI I get from my ashp , who are reputable installers etc

 

thanks

O

Smart Export Guarantee is the new scheme, as the FiT ( Feed in Tariff  ) has evaporated now. If you wish to claim this payment ( circa 5.5p/unit ) then you MUST have an MCS accredited installation.

Solar PV has been discussed here a LOT, so do some searching and you should get quite a lot of info that way. Feel free to add to existing / dormant threads ;) 

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14 hours ago, ollie said:

hi all self build last year, always thought power usage was a tiny bit on the high side.

 

i'm hoping someone brighter than me can track down where my missing kw's are going!

 

went on holiday 

so house was for idle for 10 days - house used 8.1 kw/h a day 

 

1 day usage of things that were on when we were away

 

asph used 2kwh 

sewage treatment plant - roughly 0.8kwh
mvhr - 1.5 kwh

fridge - 1kwh

(we share a bore hole with neighbour who would have been drawing water but i've been told that borehole pumps use barely any power)

 

thats 5.5kwh 

 

wheres roughly 2.5 kwh going , any ideas?

 

thanks in advance

 

ps not sure its relevant but meter is at boundary and we have a 60m 35mm armoured cable into the houses CU

 


 

Sounds like parasitic loads, 2.5kWh is a little over 100W at any given time - if you assume every electrical appliance i.e. the boiler, oven, alarm system, fire alarms, TV's & receiver boxes etc each use a couple of watts you will very quickly find 40W in a modern home, so the next 60W is not going to be difficult to track down really. What do you leave on, do you have any lighting loads, external lighting, garage door opener etc... 

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Set top boxes chew quite a bit more than we think. These and other vampire loads quickly add up. No skeletons here, just a reasonable amount of stuff left plugged in or on "standby". Can 'we' be bothered to go around room by room unplugging stuff and making sure standby means off? Not in my house lol, as that would be a full time job.

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53 minutes ago, markc said:

Would love to know how that meter gives CO2 emissions.

There is an industry standard (read average) given for every kW generated. I believe it is 0.223Kg per kWh, it falls every couple of years as more green energy comes online (another joke). Therefore it is based on this, and therefore it will be inaccurate. 

 

Like these firms who tell their customers their electricity is 100% green, that is very misleading because that is not true, all they are saying is they only buy energy from the renewable generation producers. What comes out your socket may very well be coal or nuclear generated power. 

 

So many of the facts and figures we are given are terribly inaccurate. 

 

I used to do a fair bit of electrical energy analysis and CO2 calculations and what not and I came to the conclusion that so many of these things are just a big circus.

 

If I wanted to advise on energy reduction with savings and payback calculations I needed several key pieces of information, the first I always asked for was known cost per kWh, then I would review actual survey data of loads, from that I could certainly make a good start, but where it all fell down was when you would ask an estate manager for office hours or for lighting, burning hours etc and to get the reply, oh just call it 09:00-17:00, now unless you are a government entity no office only runs from 09:00-17:00 bang on. 

 

So by the time you threw in all these assumptions and "just make it" parameters you had a document that was largely a work of fiction.

 

What I used to say to people was if you take a 100W lamp out, and fit it with a 6W lamp you will save 94W - that is a given. The cost will be the cost and you cannot put a cost on environmental benefits - you will save energy end of.

 

Where it becomes screwed up, particularly in government & local authority buildings is the disgusting figures that the DLO's (direct labour organisations) or approved contractors will charge to fit a new LED downlight in a school corridor. Something that should save over 50% on energy consumption becomes financially unfeasible because the fit price will end up being £100 quid, so...

 

32W fitting = 31.25hours lit for every kWh - call that 23p. Or 0.8p per hour

Replace with:

15W fitting = 66.66hours lit for every kWh - also at 23p. Or 0.345p per hour

Immediate saving: 0.455p per hour of burn time.

 

Cost of fitting and labour - £100 - Say £45 for a downlight and £55 a fitting install.

 

So length of time to save £100 would be 21978hours at 12 hours a day is 1831 days, or 5.017 years that is assuming, 12 hours every single day - not likley.

 

Product warranty will be up within 5 years for a good fitting, so the whole thing falls on its face as bean counters cannot allow for payback after warranty period. 

 

Having said all that, they will still come out with some totally inaccurate, often unfounded line about low energy this and environmental this. All total rubbish the lot of it. So much like your original question of how can it know, well it can't it's all just tripe, pure and simple, tripe!

 

Where I saw a success story was on a building with 16,000 luminaires, £17.50 a point installed cost + various costs for the different luminaires - payback was about 2.5 years and product warranty was 5 years with a sort of further 5 year support package.

Edited by Carrerahill
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Some CT clamps go on the meter tail, others can go on the consumer unit side - I had an OWL when it was free then switched to an Eco-Eye realtime monitor - has an LCD unit you can view and an SD card for data logging, after the purchase cost there was no monthly fee (no cloud service but you can setup a service to export to for a small fee on your own). The eco-eye used tails in the consumer unit, handy enough. There are other options, just depends where the tail goes and any monthly charge some of them have if you're ok with that!

If you find an undocumented bomb shelter & lodger under the house using that 200w do let us know?!!

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On 07/10/2021 at 22:04, ProDave said:

And what was left on standby?  Televisions, computers, broadband router, set top boxes, Fridge / freezer left on?  Or was everything unplugged?

 

 

security lights? movement sensors smoke detectors and so on

 

 

Edited by Marvin
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