I don’t believe the Vue itself stores much data at all. In my experience, when the Vue looses connection to the Emporia servers for any length of time your actual data is lost and the Emporia servers will just “fill in” the missing data with the last recorded data. Depending on the power fluctuations in your home you could end up with a small error or large error. For example, I have a pool. From 6am to 11am my pool pump runs. During that time the total load of the pool pump and the pool sweep motors are around 3000 watts. Let’s say my internet connection goes out at 10:30am and doesn’t come back on until 1pm. I’m assuming the Emporia server will just use the last figure it was sent (3KW) and fill that in for 2.5 hours. Of course, the pool pump goes off 11:00am so there are 2 hours 3KW that will show that were really not there. I know this for a fact because it has happened to me.
To be clear, I understand why Emporia does this and I really don’t have a problem with it. Like I said previously, even PG&E occasionally will have trouble reading my meter remotely and will just estimate the usage in the time period that was missed. Most of the time it’s pretty close, but there have been times where I have lost my power for over 3 hours and when I looked on my PG&E account they showed that I used power (estimated, of course) during the time period the power was out. But they eventually even it out, because the meter keeps a cumulative amount that has to be reconciled eventually.
The Vue Gen2 isn’t perfect, but the figures it gives me are very accurate, even when you factor in the occasional “outages”. What I couldn’t tolerate before was the Vue Gen1 loosing the wifi connection and not being able to reconnect without a hard reset (i.e. cut power to the Vue). That was unacceptable. Also the Vue Utility has a fatal flaw that causes it to go offline every 65 or 70 minutes. Emporia eventually gave me my money back on the Vue Utility because of this flaw. To the best of my knowledge this flaw still exists today.
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