By Matt
We initially had a single smart meter from Peoples Cooperative that monitored how much energy we used and when it was used, which then allowed them to of course bill us for used energy. In addition these data could then be accessed by using the Smarthub website, either through a browser or a phone app. This was useful in seeing when our main loads were, how much energy we used, how much we used with and without the minisplits running, and what our vampire loads totaled. See below.
This is our energy use on Dec 18, 2018, where we had a string of sunny days such that we could turn off the mini-splits and see our other base loads. From 12 AM to 4 AM the only power draws are vampire loads, the small power pulls by always on/monitoring appliances. That totals 0.2 kW per hour, which over a year means vampire loads total 1752 kWH. Might have to hunt some of these down and reduce this number. The biggest spike in electrictity use comes in the morning from shower use, and then in the late afternoon to cook dinner, with the total use when the minisplits are not running of about 20 kWH per day.
Now with the solar panels being installed, an additional meter was installed to monitor solar panel electricity generation, and the previous smart meter was exchanged out with a new one that can run backwards (when we generate excess electricity). Here are our two meters.
Of course they dont really give you a manual for these things, and they flash up several numbers so it was hard to decipher what the values meant. So I checked them a couple of times along with monitoring power use and generation to figure it out.
The meter on the left hand side flashes three numbers.
001 followed by 5 digits
-> This is the amount of energy supplied from the grid to the house
004 followed by 5 digits
-> This is the amount of energy supplied from the solar panels to the grid
006 followed by 5 digits
-> This is the difference between the two previous numbers, or the “Net” energy
If this value is positive, this is the amount of energy we have to pay for, if this is negative then we have supplied more energy to the grid than used (actually cycles back to large 5 digit number like 99950).
There is also a three dash bar (under the 01/04/06 number) that appears either in sequence left to right, meaning power is being drawn from grid, or right to left, meaning power is being pushed to grid from the solar panels.
Finally the new meter to the right measures the amount of total solar energy produced by our solar panels. It has a similar flashing number scheme of 01, 04, and 06. After monitoring it appears that the 01 and 06 number is the same and is equivalent to the amount of solar energy produced. Perhaps the two numbers will eventually be different. Perhaps one is a yearly number and one is total overall since installed, but currently they are the same. The 04 number is currently zero, and is not defined.
Recent numbers, a few days out after installation, has these numbers. Meter on the left reads 01 (00108), 04 (00078), and 06 (00029) and meter on the right reads 01 and 06 (00111). Meaning we have generated 111 kWH of solar power, 78 kWh has gone back to the grid, 108 kWH has been drawn from the grid, and we have a net draw from the grid of 29 kWH that we have to pay for.
The kWH we have to pay for will climb throughout the heating season until summer where we generate the bulk of our solar electricity, whereupon we should be “net” positive (a less than zero number on the 06 number on the left meter.)
The Smarthub web and phone app becomes less useful after installation of solar power as this has difficulty in graphing and displaying local production of power due to the solar panels.