Quick update: I took the plunge with an Emporia Vue £160 on Amazon with 16 x 50A sensors.
So far, so good. Here's some thoughts from the Amazon review I posted earlier today:
A clever product which seems to work well. Good app and great support. This was a UK DIY install.
A few notes re installing in the UK:
I managed to fit 15 50A sensors in my consumer unit. It was a bit of a squeeze but it all fitted in ok (see photos) Make sure you get each sensor round the right way, they are clearly labelled 'breaker' with an arrow (in the photo, I have two sensors, 3 and 7, upside down, I fixed that before closing the consumer unit). The 16th 50A sensor went on the PV feed live, the 200A on the live from the grid supply meter.
The device itself was definitely not going to fit in the consumer unit. I therefore shortened the 4-wire power lead and connected it to a two-core connector: red, white and blue leads to neutral, black to live, with some shrink wrap over the wires for neatness and to provide double insulation. You can see this in one of the photos. The other end of the connector is wired into a standard UK 3-pin plug which is plugged into a wall socket.
This works fine, no need as far as I can see to wire the power lead directly into the consumer unit. I guess the only issue is that you could accidentally unplug the power lead or switch the wall socket off, at which point you'd lose monitoring of course. As our socket is in the service cupboard this isn't really an issue.
I did have an issue after the install when trying to configure the device via the app. It failed at the point I told it I had solar PV. Within the app there is the option to connect to a chat support service, which I did. The guy (James) was really helpful, checked lots of things with me. He was a bit worried that the unit wasn't powered directly from the consumer unit but... eventually we discovered I had made the novice mistake of putting the 200A sensor on the live feed from the meter THE WRONG WAY ROUND (doh!) Once I flipped it, it all worked fine.
Tbf I have one further minor problem - the tip of the jack plug has broken off one of the 50A sensor leads. I don't think that was me. I actually have 15 circuits plus the PV so ideally I could use all 16 50 A sensors. I have emailed Emporia to see whether they can replace it or whether I should go via Amazon. I suspect it will be fixed without issue.
Anyway overall a good product and very good support. Aimed primarily at the US & Canada but it's working well for us.
I can now see how much of our PV generation we are actually using minute by minute, and how much we are giving to the grid. This will help us decide whether batteries would pay for themselves.