I have a new column up at The Breakthrough Institute which asks, "How Much Energy Does the World Need?" In it I apply a methodology of "backcasting" to calculate how much energy consumption is implied by postulating that in 2035 global per capita energy consumption equals that of Bulgaria, Germany and the US in 2010. The results imply a big gap in energy access as you or I might understand it and (a) projections of where the world is headed and (b) official definitions of what constitutes "energy access" (see figure above).
Lots of numbers crunched and three bottom-line conclusions reached -- comments/critique welcomed. See it here and please feel free to return and comment.