The article mentions "no more than 2,000 watts (i.e. 2 kWh per hour or 48 kWh per day) by the year 2050, without lowering their standard of living" so it is not 2kWh/day but 2kWh/hour. You are already below it in your household.
Some of it depends on the local climate and other factors that you don’t have a lot of control over though.