Smart meter accuracy

QrizB

darrude said:

Thanks for this, makes sense, so the 25 days between the 2 meter readings I made, I used 831KWh, 33.25kwh/day.  

That's just over 12,000 KWH / year if averaged out, which is the ofgem medium TDCV gas usage, which probably doesn't include much if any heating, so mainly hot water?  I'm guessing (hoping) this is still high and not my real usage!!!!

I don't know how big your house is but the four of us (two adults, two teens) in our 1950s 3-bed semi use around 4000kWh of electricity and 12000kWh of gas a year (gas is used for CH, DHW and cooking).

I read my meters monthly (or more) and have a spreadsheet that crunches the numbers for me. During April we used around 32kWh/day of gas but May was 19kWh/day. Back in January it was more like 60kWh/day!

niktheguru

Youve got smart meters right?
Why dont you download the 30min usage of your electricity and gas over a 24hr period and see when all this usage is occuring.
When do you heat your hot water? Do you heat it multiple times a day?
Do remember this winter was particularly cold so your boiler may have been working overdrive.

I would suggest downloading the bright app on your phone (by hildebrand) and allow it access to your smart meters, it will then show you your 30min usage and you can work things out from there.

darrude

niktheguru said:

Youve got smart meters right?
Why dont you download the 30min usage of your electricity and gas over a 24hr period and see when all this usage is occuring.
When do you heat your hot water? Do you heat it multiple times a day?
Do remember this winter was particularly cold so your boiler may have been working overdrive.

I would suggest downloading the bright app on your phone (by hildebrand) and allow it access to your smart meters, it will then show you your 30min usage and you can work things out from there.

meter not eligible unfortunately , but thanks for the idea.

darrude

QrizB said:

darrude said:

Thanks for this, makes sense, so the 25 days between the 2 meter readings I made, I used 831KWh, 33.25kwh/day.  

That's just over 12,000 KWH / year if averaged out, which is the ofgem medium TDCV gas usage, which probably doesn't include much if any heating, so mainly hot water?  I'm guessing (hoping) this is still high and not my real usage!!!!

I don't know how big your house is but the four of us (two adults, two teens) in our 1950s 3-bed semi use around 4000kWh of electricity and 12000kWh of gas a year (gas is used for CH, DHW and cooking).

I read my meters monthly (or more) and have a spreadsheet that crunches the numbers for me. During April we used around 32kWh/day of gas but May was 19kWh/day. Back in January it was more like 60kWh/day!

in terms of hot water usage then I can't see us been much different, 2 adults, and 1 teenager one primary school age.  Teenager does spend a bit longer than i'd like him to in shower but not excessive and wife is a bit wasteful washing hair in a morning, but not crazily so.

new(ish) boiler, and 2 year old insulated hot water tank. so can't really get much more efficient I guess.

Tallerdave

Heating is the big consumer of gas, hot water much much lower. By extrapolating our summer (HW only) gas use I reckon we use around 2500-3000kWh on hot water, whilst heating is around 40,000kWh.

theoretica

A simple sense check on the boiler - can you hear it fire up?  How often does it do so and how long?

darrude

Morning All,  Thank you very much for the feedback and comments.  I spent last night and this morning going through every bit of information I had, pictures of meter readings old bills where available etc.

There are massive gaps in readings unfortunately, however conclusion is this is nowhere near as black and white as I thought.

Electric:

7/10/16 - 3/8/18 (opening and closing readings on dumb meter), ave daily usage 16.9KWh
3/08/18 - 2/10/20 (smart meter to wife getting EV), ave daily usage 17.7KWh
2/10/20 - 21/6/21 (smart meter + ev), ave daily usage 26Kwh

Gas:

7/10/16 - 3/8/18 (opening and closing readings on dumb meter), ave daily usage 5.5m3
3/8/18 - today (smart meter) ave daily usage 6.6m3

Gas I would have thought would have seen an increase, so this makes sense (WFH).
Electric, I thought I would have seen a decrease, but maybe work from home is using more than expected.

Shocked on the EV increase though, the smart monitor on it states 580KWH since we got it, which ties in with the mileage and car energy monitor, this is only 2 KWH/day not 8, so that is way off (and makes no sense with the mileage we have done, that would give us nearly 10K miles, the car hasn't even done 2K, car is garaged and pre-heating is turned off).

I think I need to do a lot more investigation on the electric side, and maybe not trust the clamp on energy monitor like I was.

I think an energy Diary going forward is needed.

Thank you to everyone that has commented so far, certainly further investigation is needed and i'll hold off on the meter accuracy test.

Can't believe my usage (Sorry Gretta).

Thanks Again.

Daz.


EDIT, checking periods on electric:
FEB - JULY (best for analysing dates)

2018 - ave 17 kwh
2019 - ave 10 kwh
2020 - ave 14 kwh
2021 - ave 24 kwh.

[Deleted User]

darrude said:

Shocked on the EV increase though, the smart monitor on it states 580KWH since we got it, which ties in with the mileage and car energy monitor, this is only 2 KWH/day not 8, so that is way off (and makes no sense with the mileage we have done, that would give us nearly 10K miles, the car hasn't even done 2K, car is garaged and pre-heating is turned off).

I am not sure that I understand. Most EVs will do 3 to 4 miles/kWh; however, this depends on the distances driven; frequency of charging etc. 580kWhs does not look that high to me for the distance driven. How have you concluded that 580kWhs would give you 10000 miles of EV driving?

niktheguru

[Deleted User] said:

darrude said:

Shocked on the EV increase though, the smart monitor on it states 580KWH since we got it, which ties in with the mileage and car energy monitor, this is only 2 KWH/day not 8, so that is way off (and makes no sense with the mileage we have done, that would give us nearly 10K miles, the car hasn't even done 2K, car is garaged and pre-heating is turned off).

I am not sure that I understand. Most EVs will do 3 to 4 miles/kWh; however, this depends on the distances driven; frequency of charging etc. 580kWhs does not look that high to me for the distance driven. How have you concluded that 580kWhs would give you 10000 miles of EV driving?

I agree with this. 3-4 miles per kwh is average in an EV. Obviously it is lower in the winter when you use the heater in the car more, and more efficient in the summer. So getting 2000miles with 580kwh is about right. But you also said you do a lot of charging on public chargers, so is that included in this figure or separate from it.  

darrude

niktheguru said:

Dolor said:

darrude said:

Shocked on the EV increase though, the smart monitor on it states 580KWH since we got it, which ties in with the mileage and car energy monitor, this is only 2 KWH/day not 8, so that is way off (and makes no sense with the mileage we have done, that would give us nearly 10K miles, the car hasn't even done 2K, car is garaged and pre-heating is turned off).

I am not sure that I understand. Most EVs will do 3 to 4 miles/kWh; however, this depends on the distances driven; frequency of charging etc. 580kWhs does not look that high to me for the distance driven. How have you concluded that 580kWhs would give you 10000 miles of EV driving?

I agree with this. 3-4 miles per kwh is average in an EV. Obviously it is lower in the winter when you use the heater in the car more, and more efficient in the summer. So getting 2000miles with 580kwh is about right. But you also said you do a lot of charging on public chargers, so is that included in this figure or separate from it.  

The plug in monitor on the car, is showing 580KWH of use charging the car which at 3miles/kwh seems to be an accurate coloration of miles done vs power consumed.  What I was trying to say the increase from reading the meter would suggest the car had done 10K miles, which it hasn't.  Sorry for the confusion.