Thanks for getting in touch! I'll reply soon. In the meantime, check out some of my recent projects below, if you haven't yet seen them.
This is a four-series bubble chart showing that energy use is highly correlated with a country’s income. One of the main points of the accompanying research was to propose energy-use categories (low energy, middle energy, etc.) just as we have income categories (low income, middle income, high income). No high-income countries use less than 5,000 kWh per capita per year.
Size of the bubbles indicate population size.