Hi Bernardo, the device displays various values and counts kWh, but it does not keep a log, so no historical data. Greetings

It's great for testing as you can see how many watts are being produced on the display. It also totals the data, so you could theoretically check how many kWh you have produced after a week. However, if there is a power cut, all the data will be lost and you won't be able to see how much you have produced per day. I recommend this device for a balcony power station:

myStrom Smartplug WLAN Energy Control Switch 2

It comes with an app and can be easily integrated into other tools such as the solar manager if you still have a large system on the roof.