Apart from reading the laptop’s technical specifications, how do you actually measure the laptop’s total power consumption? Do you use a multimeter?
I have a "Tapo Smart Plug", but it's easier to check the current energy consumption (in W) on my grid energy meter, then pull the plug on the laptop and see the difference. That's the amount I'm actually paying for.
Another rough estimate: check the remaining battery capacity (in Wh), mentioned by your OS, and see how many hours it lasts on battery.
I think it's time to end this - very interesting - discussion on low power hardware in Meta 
Feel free to create a topic about it and mention me there to continue.
