The power edge server is going to draw way more power just because it has a “powerful” cpu(s) and other power running components. The Qnap will be much quieter and consume maybe a few watts less power than your existing setup, potentially. I wouldn’t use it though because your existing setup is way more flexible on what you can do with it.
It is not just EVs, this can be done on almost every new car in some form or another.