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Monitor Solar and import with emonPi and emonTX?

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Hi All,
I’m looking to monitor our import and PV generation, maybe other loads as well if there is the opportunity.
So I’m after advice on the best setup to do that.

The main consumer unit has the import meter and various loads that might be worth monitoring, water pump, immersion heater, garage.

Our SolarPV are located on a granny annex that has it’s own secondary consumer unit about 15-20 meters away.

There are a couple of two pair wires unterminated near each CU, I have no idea what they were for or the condition of them.

I’m guessing if I connect an emonPi in the secondary CU to monitor the generation, where there is power and data and an emonTX to the primary CU to monitor the import and other loads, it should work?

If so do I have to buy both units at the same time or can I get the Pi and add the TX later?

Is there a better way to do it?


What is along the 15 - 20 m line between there and the main c.u. (how many walls and their construction, etc)?

I think you’re probably right - I can’t think of a reason why not. But have you got a mains socket at the main c.u, because to measure the direction of power flow as well as for accuracy, both the emonPi and the emonTx need an a.c. mains to measure and get a phase reference from. The flashing LED on your meter most likely doesn’t flash when you’re exporting, so you can’t rely on counting meter pulses.

Unlike commercial firms, no you don’t, you can chop and change, add (and subtract) to your system however and whenever you wish. The only consideration is postage costs. Not mentioned anywhere, we always recommend you buy a programmer as well. It’s not strictly necessary, but it enables you to update and if you wish to customise your gear should you need to, and it makes it a lot easier to investigate should you have a problem.

Provided the radio can get through, I can’t immediately think of one. Presumably, the annex is within Wi-Fi or cabled Ethernet range of your router?

I must mention the RJ45 socket on the emonTx is not Ethernet - the emonTx will be talking via the 433 MHz ISM band radio to the emonPi, it’s that which talks Wi-Fi or Ethernet to your router.

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