The Indirect Link between Computing Efficiency Gains and Energy Savings: Focusing on the Jevons Paradox
This study began from a question: devices use less electricity every year, yet digital devices and artificial intelligence are said to be driving up electricity demand. We examined whether improving energy efficiency actually reduces energy consumption. When efficiency improves, the cost of using the same service falls, and by the law of demand, usage and new applications increase, consuming the energy that was saved. This is called the rebound effect, and the case in which the added consumption exceeds the savings, so that total consumption rises, is called the Jevons paradox. We compared three cases using published statistics: coal in nineteenth-century Britain, internet data transmission networks, and artificial intelligence. Watt’s steam engine greatly improved the efficiency of coal use, but as steam engines spread across industries, Britain’s total coal consumption surged. Between 2015 and 2021, internet traffic grew by 440% and the electricity used by data transmission networks grew by 20–60%. Electricity per unit of data fell by about 70–80%, yet total electricity use still increased. The cost of using artificial intelligence of a given capability fell to about 1/280 in roughly two years, while weekly users of a leading service grew about ninefold. In all three cases, efficiency gains slowed the growth of consumption but did not reduce it. Energy efficiency is therefore a necessary but not a sufficient condition for sustainable energy use, and total usage must be managed alongside efficiency. To this end, we proposed an efficiency-linked carbon price, mandatory minimum software support periods, and energy labeling with energy-saving default settings for digital services.