In the International Energy Outlook 2017 Reference case, total world energy consumption rises from 575 quadrillion British thermal units (Btu) in 2015 to 736 quadrillion Btu in 2040, an increase of 28%. Most of the world’s energy growth will occur in countries outside of the Organization for Economic Cooperation and Development (OECD), where strong, long-term economic growth drives increasing demand for energy. Non-OECD Asia (including China and India) alone accounts for more than half of the world’s total increase in energy consumption over the 2015 to 2040 projection period. By 2040, energy use in non-OECD Asia exceeds that of the entire OECD by 41 quadrillion Btu in the IEO2017.
In the long term, the IEO2017 Reference case projects increased world consumption of marketed energy from all fuel sources—except coal, where demand is essentially flat—through 2040. Renewables are the world’s fastest-growing energy source, with consumption increasing by an average 2.3%/year between 2015 and 2040. The world’s second fastest-growing source of energy is nuclear power, with consumption increasing by 1.5%/year over that period.
Although consumption of nonfossil fuels is expected to grow faster than fossil fuels, fossil fuels still account for 77% of energy use in 2040. Natural gas is the fastest-growing fossil fuel in the projections. Global natural gas consumption increases by 1.4%/year. Abundant natural gas resources and rising production—including supplies of tight gas, shale gas, and coalbed methane—contribute to the strong competitive position of natural gas. Liquid fuels—mostly petroleum-based—remain the largest source of world energy consumption. However, the liquids share of world marketed energy consumption falls from 33% in 2015 to 31% in 2040, as oil prices rise steadily, leading many energy users to adopt more energy-efficient technologies and to switch away from liquid fuels when feasible. (Source: EIA)