Re-examination of the concept of “Primary Energy” for a Precise Analysis of Energy Issues (Published)
The concept of “primary energy” should be re-examined in order to grasp a complete view of energy issues, and to evaluate the precise effectiveness of renewable energies, especially by non-thermal means. In many energy statistics, the term “primary energy” is always used, and the unit is often “toe” (ton of oil equivalent), which is based on the caloric value of oil. Since there are several kinds of energy supplied and consumed in society, the concept of “primary energy” is important and convenient to calculate the total amount of energies, in particular when fuels are burned and utilized. However, the situation is complicated when electricity is supplied from renewable energies without fossil fuel consumption. There are several conversion factors between fuels and electricity used in the statics of the IEA (International Energy Agency), which results in the confused meaning of the total amount of the “primary energy” expressed by “toe”. In this study, the author proposes a common conversion factor from electricity to “toe” in energy statistics, which will make it easier for us to analyze energy issues and to evaluate the effectiveness of renewable energies and select a better energy source.
This article contributes to explaining the recently observable acceleration in the growth of output in renewable energies, through studying the fundamental role of renewable energies in sustaining human settlement. A model of general equilibrium is introduced, based on the logic of the original production function by Cobb and Douglas, where the size of the human population in a given place at a given time is in equilibrium with the available food and energy. Empirical check provided for the model strongly suggests that renewable energies can sustain the majority of local human populations on Earth, and most countries, with the intriguing exception of China and India, can sustain significantly bigger populations than their present ones, by reorienting their economies totally to renewable energies.