Important message for WDS users

The IEA has discontinued providing data in the Beyond 2020 format (IVT files and through WDS). Data is now available through the .Stat Data Explorer, which also allows users to export data in Excel and CSV formats.

Tracking energy investment

The way investment is measured across the energy spectrum varies, largely because of differences in the availability of data and the nature of expenditures. This document highlights the methodology used to ensure that the estimates are consistent and comparable across sectors in the World Energy Investment 2025 (WEI 2025) report and other publications from the International Energy Agency.

The IEA measures investment as the ongoing capital spending on assets. For some sectors, such as power generation, this investment is spread out evenly from the year in which a new plant or upgrade of an existing one takes a final investment decision (FID), i.e. when a project reaches financial close or begins construction) to the year in which it becomes operational. For other sources, such as upstream oil and gas and liquefied natural gas (LNG) projects, investment reflects the capital spending incurred over time as production from a new source ramp up, or to maintain output from an existing asset.

For energy efficiency, the measurement task is more complex and much of the expenditure is by consumers for whom purchases of more efficient goods are not investments per se. In WEI 2025, as in other recent IEA reports, investment in energy efficiency aims to reflect the incremental spending by companies, governments, or individuals to acquire a piece of equipment that is more efficient than the local market average. Due to the different possible methodologies available, this estimate of energy efficiency investment is not definitive but still included to provide a comparison with the scale of investment in energy supply. Fossil fuel and power sector investments are those that raise or replace energy supply, while energy efficiency are counted as those that reduce energy demand.

Investment estimates are derived from International Energy Agency (IEA) data for energy demand, supply and trade, and estimates of unit capacity costs, analysis of which benefits from extensive interaction with industry. By default, investment data are given in year 2024 US dollars, adjusted using country-level gross domestic product (GDP) deflators and 2024 exchange rates. Unless otherwise stated, all time series and historical comparisons are presented in real 2024 US dollar terms, adjusted for inflation.

This investment approach mirrors real-world practices and aligns with capital expenditure in financial reporting. In reality, time lags and varied spending occur between FID and project operation. Where possible, financial and energy performance metrics are included to better reflect asset turnover and capital commitment decisions. Other areas of spending – including operating and maintenance expenditures, R&D, financing costs, mergers and acquisitions or public markets transactions – remain important for energy sector development, and are analysed on a standalone basis in IEA investment work, but are not included in the calculations of WEI 2025.

Clean power
Fossil power: unabated Hydro and pumped hydro storage Solar PV: buildings and utility-scale Solar CSP Wind: offshore and onshore Tidal Geothermal Bioenergy and renewable waste Renewables: Natural gas w/ CCUS Coal w/ CCUS Oil w/ CCUS Bioenergy and waste w/ CCUS CCUS Battery storage: buildings Battery storage: utility scale Hydrogen Ammonia H2-based fuels Transmission and distribution Battery storage
Nuclear Low-emissions power p Investment in ower
Natural gas: unabated
Coal: unabated
Non-renewable waste
Oil: unabated
Fossil power Investment in e nd use In this area the aim is to capture the incremental cost vs a business as usual baseline: The IEA defines an energy efficiency investment as the incremental spending to acquire equipment that consumes less energy than would otherwise have been used to provide the service, such as lighting, heating or mobility, had the consumer not bought a more efficient option (i.e. the baseline).
The additional cost of a more efficient alternative can represent a small share of the total spending on a particular energy-related good or service. Similarly, additional investment in decarbonisation technologies or other fuel switches is also represented in end use investment as the incremental cost vs. a baseline technology. However, changes where investments are reduced are excluded from the calculations. Furthermore, spending is typically carried out on the balance sheets of many millions of households and firms, often without external financing. As much as possible, a bottom-up analysis using data on sales of efficient goods is used.
Water/space Heating/cooling Cooking Switch from fuel to electricity for heating, cooling and cooking. (e.g. Heat Pumps) Appliances Building materials (envelope and retrofits) Heat Pumps Bioenergy Geothermal Solar home systems (solar heating) Hydrogen Other renewables Road vehicles (cars, buses, trucks, and two- and three-wheelers) Domestic navigation Rail transport Maritime and aviation (at the aggregate world level) Industrial energy management systems Fuel efficiency Equipment efficiency (such as motors) Deployment of best available technology Bioenergy Geothermal Solar thermal Hydrogen and H2-based fuels Carbon capture Heat Pumps for industrial heat Electric boilers Electrification of energy-intensive processes Battery and plug-in hybrid (Road) Fuel cell (Road) EV charger utility (Road) Electricity, Hydrogen and Bioenergy for transport (Rail, navigation and aviation)
Buildings Transport Energy efficiency Electrification Renewables for building use Energy efficiency Electrification
Industry Electrification Energy efficiency Renewables and other decarbonisation technologies CCUS
CCUS infrastructure Electrification f Investment in uel supply
Fossil fuels
Reduce flaring Methane abatement
Mining
Refining Reduce emissions Oil & Gas Infrastructure Production Infrastructure Coal
Low-emissions fuels
Production without CCUS Production with electrolyser CCUS for hydrogen production Production with CCUS Processing Liquid biofuels and biogases Hydrogen and hydrogen-based fuels
Direct Air Capture Off-site CCUS facilities and infrastructure includes capital expenditures in exploration, drilling and lifting. includes transmission, distribution and seaborne trade. CCUS for hydrogen production only captures the CCUS part (capture and compression) of the investment. Hydrogen processing includes hydrogen-based fuels production. refers to all carbon capture and sequestration activities conducted outside of the oil and gas, power, and industry sectors. For reporting purposes, it has been attributed to the fuel supply sector. Oil and natural gas productionInfrastructureOff-site CCUS facilities and infrastructure Infrastructure Transmission and distribution lines Grid equipment (transformers, substations, etc.) All end-use investment is in clean energy