I have a Shelly 1PM-plus set up to run my solar hot water booster. It is integrated with Shelly in HA and works.
The element is 2300W (240v).
The Shelly is showing that it draws 2300 watts when on, but the daily Energy helper that I set up is showing a much higher energy draw. After an hour at 2300 watts, the reading shows 2.9 to 3kwh. I would expect 2.3kwh so I am assuming there is something off in the way the data is collected and calculated.
I have looked at the calibration service under Developer Tools, but I am not sure how to use that. Ideally I would like to take the state and multiply by 0.8 to get a realist value (2.3/2.9).
Any advice or suggestions (for a 5 year old please!)
The Shelly energy meter doesn’t reset every day - I think it might reset every fortnight or similar, so I am getting a high reading like you. It’s currently showing 58.21kwh and as best I can see from the history graph, that was zeroed somewhere around 11 days ago. (see history graph)
The flat line is because we have had several days of sunshine and there was no need for the booster - but this graph shows that so far today the booster has used circa 8.5kwh.
The daily meter that I set up using the Utility Meter Helper resets every day and is currently showing 8.45kwh
So the two graphs agree… but the booster has been on for three hours and so should have used circa 6.9kwh. The Shelly power sensor shows a draw of 2.3kw and a clamp meter on the element shows 2.3kw.
This makes me think the Shelly energy sensor is not calibrated properly - ie their time/watts calculations are out and I just want to correct that so I can see an accurate reading. I was hoping the Calibration commands under Developer Tools would help, but it looks like it only take a single number… or I can’t work out how to use it.
I am thinking a value template sensor might be the way to go.