World Energy Outlook 2023
About this book
World Energy Outlook 2023, published annually by the International Energy Agency (IEA), is the most influential global energy analysis and projections publication, providing the definitive forward-looking assessment of how global energy supply and demand may evolve through to 2050 under different policy scenarios. The 2023 edition analyses a world transformed by the energy crisis of 2022-2023, the unprecedented scale of clean energy investment, and the persistent gap between stated climate commitments and the emissions trajectories implied by current policies. The 2023 WEO opens with a headline finding that represents a historic milestone: under the IEA's central scenario (the Announced Pledges Scenario — APS), fossil fuel demand is projected to peak by the end of the 2020s across all three fuels — oil, gas, and coal — for the first time in the history of the energy system.
This represents a structural turning point driven by the rapid scaling of solar PV, wind power, and electric vehicles, which are displacing fossil fuel demand across the electricity, transport, and heating sectors simultaneously. Three scenarios organise the analysis. The Stated Policies Scenario (STEPS) reflects current policies and regulations without assuming additional commitments, showing continued fossil fuel growth.
The Announced Pledges Scenario (APS) assumes all net-zero pledges and climate commitments are met fully and on time, leading to a faster energy transition. The Net Zero Emissions by 2050 Scenario (NZE) describes the pathway consistent with limiting global warming to 1.5°C with a 50% probability, requiring complete transformation of the energy system within 27 years. The 2023 edition pays particular attention to the energy security-affordability-sustainability trilemma in the context of the geopolitical energy crisis.
Russia's invasion of Ukraine accelerated Europe's transition away from Russian gas, but triggered significant investment in new LNG capacity and coal-to-gas switching that may lock in emissions for decades. The IEA examines how countries can navigate this trilemma — maintaining energy security and affordability while accelerating decarbonisation. Detailed sectoral analysis covers electricity (the central vector of decarbonisation, with renewables approaching 90% of global new capacity additions), transport (EV adoption trajectories by vehicle type and region), buildings (heat pump adoption and building envelope efficiency), industry (green hydrogen, electrification, material efficiency), and fossil fuels (the investment and stranded asset implications of peak demand).