Since the beginning of time, people have gradually consumed more and more energy through advancements in technology. Consumption was initially around 3 kWh per day per person and mostly used for nourishment. Because of the necessity and possibility of heating for warmth, consumption in prehistoric times rose to 6 kWh primary energy per day.
In the Middle Ages, people in Europe wore more clothes and created more elaborate houses and churches, increasing the daily energy consumption to 24 kWh. Today, we need less than 6 kWh are for pure nourishment, with more than 12 kWh for the preparation and transportation of food. US and German citizens consumed in 2013 about 228 and 128 kWh, respectively.
The 2013 data on the energy consumption (BP) and the population (PRB) show that the average daily energy consumption of a person in India is still 15 kWh. But China (67 kWh) exceeded already the world average and is striving to consume approximately the same amount of energy as industrial nations in the next few decades. In 2013, the world primary energy consumption was 12,73 billion toe (ton of oil equivalent). With a world population of about 7 billion, we have now a world average consumption of primary energy of 57 kWh per day per person.
If the world population increases to 10 billion as expected, and all countries advance to match the present consumption of US, the world energy demand will increase nearly sixfold.