Any reason for the first opamp?
Circuit 1 uses two non-inverting inputs and their high input impedance as a differential amplifier suitable for low voltage sensing without significant loading current but poor CMRR due to R matching needed.  Each input impedance is implied by the Op Amp input bias current.

Circuit 2 has several design violations ( including U1B-out to 240V Neutral and trying to measure AC current with poor CMRR and no isolation) It also is not the same as CCT 1.  


  Note how above CCT 1 is pleasing to the eye and figure out why that is so.  :)


Further info below


FWIW https://meettechniek.info/diy-instruments/arduino-wattmeter.html