I have been using this for 3 years and it’s been rock solid, but I’ve replicated (some of) it with an arduino/rpi combo, so I no longer need it. It’s the rev02b version - it’s currently up to rev3 but not a great deal has changed worth changing for, in my opinion.
So I had 2x pulse meters hooked up to this, but you can also use current clamps. I also have an updated firmware on it so it publishes/brokers MQTT messages, so it’s also been my smart home MQTT broker for some time now.
It’s natively supported by pvoutput and mine has been uploading to pvoutput for the whole time.
More info here:
https://www.flukso.net/content/fluksometer-v3e
https://www.flukso.net/
I was after $50, which is a lot cheaper than new.
Edit: Sold