The World's Appetite for Light: Empirical Data and Trends Spanning Three Centuries and Six Continents

Abstract

We have collected and self-consistently analyzed data for per-capita consumption of artificial light, per-capita gross domestic product, and ownership cost of light. The data span a wide range (three centuries, six continents, five lighting technologies, and five orders of magnitude), and are consistent with a linear variation of per-capita consumption of light with the ratio between per-capita gross domestic product and ownership cost of light. No empirical evidence is found for a saturation in per-capita consumption of light, even in contemporary developed nations. Finally, we extrapolate to the world in 2005, and find that 0.72 percent ($437B/year) of world gross domestic product and 6.5 percent (29.5 Quads/year) of world primary energy was used to produce 130 Plmh/year of artificial light.