Just received my first bill from HK Electric. Out of curiosity, I checked that I consumed 522 units (I am not quite sure what unit that is) for which I have to pay HK$574.79. There is a remark at the bottom of the statement that reads "CO2 emission per unit of electricity consumed = 0.78kg". The bill is for the month of December and I have traveled approximately 2000km in that 1 month period. So, that means I have had 522 x 0.78kg = 407kg CO2 emission in this month. Divide that by 2000km, that means each km I consume 204g. I compare that to a Porsche 911 GTS CO2 emission 212g/km (and some others around two hundred something gram/km), I wonder eventually are we really giving significantly less CO2 emission or we just want to believe it is true!! Is my calculation about right?? Can someone help to verify??