Monday, October 17, 2005

How much energy?

According to the World Energy Assessment, the world consumes about 400 Exajoules/year of primary energy (1 EJ = 10E18 J = 24 Mtoe = 0.96 Quad = 278 TWh), or about 60 GJ per capita per year. But energy use is by far not spread equally. North Americans consume 350 GJ, Europeans 150, and Africa only 40 GJ. Russia/CIS consumers 150 GJ, i.e. the same amount as Europe, but produces much less units of GDP, and hence welfare, per unit of energy consumed.
Europe could save 30% of its primary energy use, establishing a benchmark of 100 GJ/capita for a fully industrialised society. For a future world population of 9 billion people, this means a need to plan for an energy system of 900 EJ/year/capita. With 'technological leapfrogging', developing countries could avoid some of the mistakes made by Europe, settling the figure to for example 800 EJ, or slightly below 100 GJ per world citizen.
Not managing this growth properly, may result in a much more energy-vorous system. At 350 GJ per capita, a world of 9 billion would consume over 3000 EJ, requiring for example 33,000 nuclear power plants, 150 million wind turbines, 4 million square km of solar arrays, or any combination thereof.
Another issue is that we an increasing share of renewables and decentralised generation, and with the new energy technologies that can be expected in the future, we may need a new system for energy accounting. The current system is largely based on fossil fuel accounting, and does not properly address modern energy forms, which have been of marginal importance until recently.

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