[FrostKiwi]

Interesting! Can you reference some numbers? Other processes such as SLM and DED require a powerful laser, starting from 3000W. When talking about copper specifically and especially when wanting higher processes speed, you need higher wavelength blue laser reaching 10000W of power. But on the flipside, the process can be quite quick. Non-laser alternatives like Metal Paste Deposition need a furnace, though I'm unsure of the power requirements there.

Any idea or references on how ECAM would compare to that?

[kragen]

every metal atom requires two electrons (or three for some metals), and you typically need 1–3 volts, and sometimes there are side reactions that waste most of your electrons; probably 'faradaic efficiency' or 'coulombic efficiency' is the term to google

slm and ded and metal paste deposition just have to rearrange some crystal structures; in electrolysis (including ecm machining) and electrodeposition you have to actually rip molecules apart, atom by atom and electron by electron

basically you're charging a battery, so you can get a rough idea by thinking about how much energy a battery could store if it was the same size as your desired workpiece