The indicators you choose depend on what you want to know, which depends in turn on your perspective on policies and issues.
Indicators are like stock market indices.
They mark important changes in quantities of interest to policy makers and analysts. They are usually based on a disaggregated view of the link between energy use and economic or human activity. They are formed from data and from estimates where data do not exist. Many are quantities or indices, some are intensities formed by dividing one datum by another. Indicators include both measures of structure or activity as well as measures of energy use per unit of activity.