MacKay's entire analysis is posed using KWh (and multiples) as a standard unit for energy. Why? From memory he stated it was because everything would otherwise

MacKay's entire analysis is posed using KWh (and multiples) as a standard unit for energy. Why? From memory he stated it was because everything would otherwise need to be converted to Joules (or multiples) and KWh were at least a common enough energy unit that people "think" in them for resource estimates.