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Welcome, Adrian,

Unfortunately, you cannot do it according to your diagram. Because the emonTx needs the timing between the voltage and the current waves to be exact, it is not possible to use a radio link where you have shown it.

Is it possible to run a small ('microphone' - twin twisted pair type) cable between your inverter and your fuse box? What is the distance? You should be able to have 10 - 20 m of cable with no problem.

If that is not possible, then you will need to have 2 x emonTx V3, one at the inverter and one at the fuse box. Each will have one 9 V ac adapter and one CT. You do not need a separate 5 V dc USB adapter with the emonTx V3. You can then calculate your electricity use (= grid power + PV power) in emonCMS and in your emonGLCD (if you intend to have one).

I think this sort of config will be more and more common. My setup is very similar with the PV Array on the shed roof and the emon back on the house. This does mean that any load at the shed is not being measured, but for me it is accurate enough. Another option depending on your grid-tie inverter is to take the feed from that. I have thought about doing it that way but lack the skills to write the code ;-)

Regards

Nathan

I have a similar set-up, and I'm using a special logger device for the inverter, that I can access via http. That way, I can get the PV data via an shell script over the network, instead of using a clamp.

Are you able to tell me how you get the data from the inverter? I can access the inverter via http and it can output a xml file I am unsure how to get this into emon.

Cheers

Nathan

Robert:  emonTx needs the timing between the voltage and the current waves to be exact, it is not possible to use a radio link where you have shown it.

For that particular leg, I wonder if you could take advantage of the observation that most grid-tied inverters only produce real power.  That leg is one of the few legs in my house where I consistently see a PF of 1.  So if he does have a mechanism to broadcast Irms across a radio link, the old "Irms * Vrms = apparent power =  ~real power" shortcut might be spot on.

I know there are some fairly recent German inverter standards that allow the grid manager to remotely request inverters start injecting reactive power, so mileage may vary depending on where you live. 

Hi!

First thanks all for the help!

My grid is connected so far away from the fuse box, about 15m :( .  I think the best choice is make a new line from the grid to the fuse box... if I can :)

Thanks again!