Get Power Used from smart-meter on main fuse & PV

Hi all,

I have a Flukso V2 where I hooked two smart meters using pulse signals:

1) "main" meter located on the main fuse box (between grid cable and household fuses).
2) "PV" meter located right after my inverter, that is injecting power into a second fuse box (in my kitchen)

I'm not an expert in electricity so I'll try to draw a schema of the setup:

GRID ---- "main" meter ---- Main fusebox ---- Secondary fusebox ---- "PV meter" ---- Inverter

The PV injection into the secondary fusebox can't be changed.

Before installing PV, the "main" meter was used to monitor household consumption. However, since the PV is installed and generating power, the signal of the "main" meter that is pushed to the Flukso seems to take into account generation (PV) and househould consumption. This results in a signal that is equal to the household consumption when no power is injected (see red line in figure below, before 10:30 AM and after 6:30PM). When power is injected, the main signal follows the PV (blue line) and the difference between the blue and red seems to be equal to the net consumption (import/export from/to the grid).


Does this make sense?

I wanted then to push the data to pvoutputs and given assumptions above, I have setup the auto upload from the Flukso device like this:

In the first device, I subtract the Generated power ("PV" Meter) from the Power recorded at "Main" Meter. This is, according to me, returning the Net Consumption and not the Power used.

In the second device, I get the "PV" meter data only which I'm sure is Generated Power only.

The result on pvoutput is this:

The Power Used seems therefore to show the Net Consumption and not the actual power used (without pv contribution). Therefore I'm not sure that the Net Energy (import or export) figures are correct.

My question: Is it possible to setup the automatic upload in order to get the Power Used instead of Net Consumption in my situation? Does someone can help me to set it up on pvoutputs?

I asked some help from their forum and someone suggested to replace my current configuration by:

Primary device
- Direction = Solar
- Sensor = PV Meter

Secondary device
- Direction = Net
- Sensor = Main Meter

This now yields this:

There is still something I don't really get: in the graph above, we can see that the Power used follows directly the PV generation. Therefore there is a peak in the consumption directly linked with the peak of production. My consumption is therefore way too high as it seems to take into account the PV generation.

I tried several setups but can't get it right... So I just would like some help from you guys, and hopefully be able to extract the power consumption given my electrical setup.

Thanks a lot,

gebhardm's picture

What does the main meter do when you produce more power than you use? A Ferraris Counter would run backwards (if there is no reverse lock). Thus, either it tells "Zero" (reverse lock) or "I currently feed to to the grid" (with a negative sign on "consumption").
The pity is, that you cannot detect the direction of current flow with a pulse meter with single pulse output (and the FLM cannot either).
I always asked to prohibit physics, as it brings nothing but trouble ;-)

leroygr's picture

The main meter doesn't distinguish the direction of current so it still considers I'm consuming when production is higher. I guess I have to accept the situation ;-)