Variance between sensors on mains vs utility meter

[OBSSD]

As a bit of a data nerd, I’ve really enjoyed having the 16-sensor Emporia Vue 2 hooked up and have added 8 Emporia plugs to gain additional insights.  Installation was straight-forward but a bit of a headache, dealing with the bulky CT clamps and big mass of wires.  I have no solar (yet) and probably won’t use the Vue 2 to measure production, but rather focus on my raw consumption.   I’ve documented a number of suggestions in the following threads:

App suggestions

Hardware suggestions

Now that I’ve completed my first full billing cycle, I exported the raw Emporia data to compare with my utility’s meter readings and was a bit surprised at the difference between the two.  Summing up usage of both mains from the 1DAY log, over the same date range as my meter readings, the Emporia was 7% lower than the utility (98kWh less).  Has anyone else seen similar results?

I’ve checked the hourly log and its totals match the daily totals so it doesn’t look like any summation issues on the Emporia side.  I’m going to try reading the meter myself at the same time of day on a weekly basis and compare my readings with the hourly Emporia logs for a while to see if it’s consistently lower.

[OBSSD]

With an additional 3 weeks of measurements, I’m continuing to see a 7% lower reading from the mains on my Vue 2 than from the utility meter.

[LAM69]

100% agree, I have been keeping an eye on the Solar generated on the roof and how much extra I am bringing in, and have found since installing the monitor it measures approximately 7.6% less on average than the Utility meter here in the UK, so it’s more indicative of use which is still useful but not 100% accurate.

[Peter]

If you want to get up close and personal with the board, you can download, and edit, and replace the factory calibrations.

https://flaviutamas.com/2021/reversing-emporia-vue-2

[dawdawdo]

This is exactly what I came here to post about and it happened to be the first topic, : )

I see a similar difference (electric company observes higher usage than the board), however, I get around a 1.5% difference over a six month period and it’s not really consistent – it has varied between +2.2% to -1.4%. Without a meaningfully similar point of reference, it feels like about the right level of noise to expect, but I’m curious to hear thoughts from others.

Thanks!

[OBSSD]

I stopped reading the meter myself (which gave accuracy down to the hour) and started going off my utility bill so I’m definitely seeing more variability month-to-month but I’m still averaging 7.1% lower on my Vue2 mains over the past 6 months.

[OBSSD]

I finally got around to reaching out to Emporia support (awesome service, BTW!!!) – it was a simple matter of replacing my main CT sensors.  I’m now tracking well within the 2% advertised accuracy (usually around 0.5%).

[rocketdog1989]

I know this is an older thread but I was wondering if the utility company is cheating somehow. Ever since the smart meter was installed my bill went up quite a lot. I had bad run-in’s with the power company claiming I was stealing electricity and sent the police to my house and had me detained while they did an illegal search and seizure of my home and took personal documents like my birth certificate and social security card. They couldn’t prove that I stole electricity so they dropped the case in court. When they cut their wires from my service, they damaged the entire service and it had to be replaced and inspected and permits to be pulled. I also had to pay a 1000 dollar deposit to have my electricity turned back on. Once my bills went from 75 dollars a month with a single person living in the home to around 150 to 250 a month consistently. This is when I decided to put in an emporia energy home monitor and it’s showing I should be using around 75 to 100 a month in electricity when my bill is 200 to 250. The power company told me the smart meter was way better at detecting power usage than the cheap chinese junk I had installed. They claimed that emporia is and has always been inaccurate at detecting power draw and they even told me it was illegal and not up to code to have extra equipment installed in my electrical panel and that I should probably remove the emporia from my electrical equipment. The lady even said that the emporia could also interfere with the smart meter and it’s communication and that I would be responsible for any data error or damage to their equipment as a result of using any non-utility equipment installed in my service panel. I am not the only one on consumers energy that complained of extremely higher bills after the smart meter was installed. A friend of my lives a few miles north of town and uses Great Lakes energy and he uses around 65 to 75 a month in electricity and it might go to 85 in the summer when hes running A/C.

• This reply was modified 2 years, 2 months ago by rocketdog1989.

[LAM69]

So I recently had a Smart Meter installed and the variance between the monitor and what I am being charged has increased, the Vue says I have used 943KW and my Energy Company is saying 1115KW, that’s an 18% increase, I do have Solar but can’t believe this is the issue, in light of what is going on in the world I need the assurance of knowing what I am looking at, unsure what to believe 🤔

• This reply was modified 2 years, 1 month ago by LAM69.

[cbbspike]

So I have not done a full cycle yet, I was off by 3 days. Vue was installed on 10/1, but reading for the month was 9/28. However I am shocked at the difference. Electric company tells me I consumed 51 kwh/day, but my Vue is telling me 25 kwh/day. What is going on? I am going to be checking with support I must have installed the Vue 2 incorrectly.

[DeeBee]

I noticed a roughly 8% variance of current between Vue readings on mains input and my meter. Support suggested putting all three sensors on my mains input and I have seen between 14% and 18% variance between the three sensors, purportedly measuring the same supply. As the sensors are specified as +-2% accuracy. I would expect no more than a 4% variance between them. Can anyone explain that?

[Author]

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