Newbie questions

Hello, I am a complete newbie and I lack time 4 reading all this stuff…

can someone tell me I can operate on emontx 3.4 only through wifi network?
What is the accuracy of power consumption reading on 220V line?
I have a beaglebone black for my “smart home” and I need to get reading of power consumption from any desired time. Is that possible without wifi? If I can map network drive on emontx and write readings in some file, then there should be no problem. can I do that?

@korenje accuracy within 1 or 2%, or better, if you calibrate Learn | OpenEnergyMonitor and use a proper Ac - AC adaptor Power Supplies - Shop | OpenEnergyMonitor
5% to 10% if you don’t.
You could use a network or use an ESP emonTx WiFi Adapter - Shop | OpenEnergyMonitor