Real time home energy monitor for solar PV and battery?

[AndyC_772]

Hi all,

This week we've had a solar PV system with battery storage installed. The system consists of a Fronius Primo solar inverter and a Lux battery inverter, both of which come with wi-fi and a manufacturer's on-line 'portal' which is able to receive real-time usage data and present it in various forms through their respective web sites.

Neither is ideal, though. The Fronius equipment isn't aware of the battery system, so it can't show any information relating to that, and the manufacturer has decided to hide basic information like "how much energy have I exported to the grid this month?" behind a 'premium' subscription 

The Lux site is much more comprehensive, but it still only records an instantaneous measurement every 3 minutes. Also the inverter seems to randomly lose its connection from time to time and I've yet to figure out what causes it. (It's not bad wi-fi).

Finally, from a general privacy and security point of view, I'm not really happy about having my real-time energy consumption data transmitted to anyone, anywhere, for any reason.

With all that in mind, I'm interested to see if there's a device available which I can hook up with a few current transformers, which will provide reliable, regular, local logging and monitoring of my energy usage. Maybe a dedicated piece of hardware, or perhaps something like a Raspberry Pi with a few sensors attached.

I'm not looking to develop something myself from scratch here. Must be off-the-shelf.

Any suggestions please?

[nfmax]

Does your system have energy meters (PV generation, battery output)? Do they have flashing 1/WHr LEDs, or even open collector meter pulse outputs? I use a phototransistor glued in front of the LED and count the pulses in a commercial datalogger (a Honeywell JACE, though it is very old, uses no longer supported PC software, and I have just ordered a Raspberry Pi based replacement) The datalogger holds the last 3 days (maximum) of data, and my music server wakes up every night and downloads all the new data, which I keep in CSV files organised by year/month/day.

You can get DIN-rail mounted energy meters if your system doesn't have them.

[NiHaoMike]

Neither is ideal, though. The Fronius equipment isn't aware of the battery system, so it can't show any information relating to that, and the manufacturer has decided to hide basic information like "how much energy have I exported to the grid this month?" behind a 'premium' subscription 

If it doesn't have sensors installed on the grid input to the main panel, it can't display that since it doesn't know that.

What voltage is the battery and the solar array? You can use clamp on Hall sensors to monitor the currents, but I'm not aware of any reasonably cheap off the shelf isolated DC voltage sensor other than a cheap multimeter with RS-232 output.

On the AC side, power meter modules are commonly available.

[NivagSwerdna]

For DIY... I've used bits from https://openenergymonitor.org/ in the past

There are probably better, more commercial, solutions now...