Every year, the Statistical Review of World Energy follows energy through each stage of the energy system. It records the production of primary energy, secondary and final energy, international trade, electricity generation, energy supply and consumption, and the emissions associated with energy use. Looking at these stages together helps explain how energy moves from natural resources to the services we rely on every day, while also allowing users to compare countries, technologies and long-term trends using worldwide data that is compiled using expert analysis and tried and trusted techniques by the Energy Institute.

Nations are distinct entities in a political and economic sense, so they are the fundamental reporting unit of energy measurements in the Statistical Review. Most nations manage their own energy system in their own way. In addition, many oil producing countries have national oil companies (NOCs). However, many energy producers and developers are international, including international oil companies (IOCs) such as BP, Shell and TotalEnergies, and renewables developers such as Ørsted and Masdar, as well as exploration and mining companies such as Anglo American or Rio Tinto.  

Just because a commodity is produced in a certain country does not mean the country owns or controls that supply chain. Note also that some nations’ production may be affected by other international factors, such as members of the international trading bloc OPEC.  

What is the energy supply chain?

The energy system begins with primary energy – energy that exists in nature before it has been converted into another form. Examples include crude oil, natural gas, coal, uranium, sunlight, wind, flowing water and biomass. These resources are extracted or captured and then converted into forms that are easier for people and businesses to use.  

Many of these resources are transformed into secondary energy or energy carriers. These are forms of energy that have been processed for practical use. For example, crude oil is refined into petrol, diesel or jet fuel; coal and natural gas can be used to generate electricity; and renewable energy sources such as wind, solar and hydropower are converted directly into electricity. Electricity itself is an energy carrier because it delivers energy to homes, businesses and industry rather than existing naturally in the environment.  

The final purpose of the energy system is to provide energy services – the things people actually want. We use electricity to light buildings, run computers and power machinery, petrol for transport, and natural gas for heating. In other words, primary energy is converted into useful forms of energy that ultimately provide the services people and economies need.  

Converting energy into useful forms

Oil refining is one example of this conversion process. Crude oil is processed in refineries, where it is heated and separated into different groups of products. These include lighter products such as liquefied petroleum gas (LPG) and petrol (gasoline); middle distillates, such as jet fuel, kerosene and diesel; and heavier products, including fuel oil, lubricants and bitumen. The mix produced depends on the type of crude oil and the refinery.  

Refineries can also process condensate, a light hydrocarbon liquid produced alongside natural gas. Because it has similar properties to very light crude oil, condensate can be processed alongside crude oil or separately in a condensate splitter to produce a range of petroleum products.

Electricity: from capacity to output

Electricity is unique among energy commodities because, unlike oil or coal, it cannot easily be stored at large scale. Supply and demand must therefore be balanced continuously. Every second, electricity system operators adjust power generation to match demand so that the grid remains stable. If demand suddenly increases, additional generation must come online almost immediately.

If generation exceeds demand, output must be reduced or excess electricity stored where possible. Maintaining this balance is one of the most important tasks of modern electricity systems. When comparing different electricity technologies, it is important to distinguish between capacity and output. Capacity is the maximum amount of electricity a power station or wind farm can produce under ideal conditions, usually measured in megawatts (MW) or gigawatts (GW). Output is the amount of electricity actually generated over a period of time, typically measured in terawatt-hours (TWh). A wind farm may have a capacity of 1GW, but because the wind does not blow constantly it will produce less electricity than if it operated at full power every hour of the year.  

This relationship is known as the ‘load factor’ (or ‘capacity factor’). Gas-fired power stations, which can operate whenever fuel is available, generally achieve much higher load factors than wind or solar farms, whose output depends on weather conditions. Even so-called ‘baseload’ sources of electricity such as nuclear power will not achieve 100% load factors because of the need to stop the plant periodically to refuel and perform maintenance, or in case of unexpected circumstances.

Energy trade and energy security

Very few countries can produce all the energy they need. A very few countries have access to energy reserves far greater than their domestic requirements. As a result, energy is traded extensively around the world. Oil is transported by tanker, pipelines or rail; natural gas moves through pipelines or is shipped as liquefied natural gas (LNG) by being cooled to around –162°C; coal is transported mainly by bulk carrier ships and rail. Electricity can also be traded between neighbouring countries through interconnectors – high-voltage transmission cables that allow electricity to flow across borders.

International trade helps improve energy security, balances regional shortages and allows countries to make use of their most abundant resources. However, it also creates challenges. Countries that rely heavily on imported energy can become exposed to supply disruptions, geopolitical tensions and price volatility. Events such as wars, natural disasters or disruptions to shipping routes and pipelines can quickly affect energy availability and prices around the world. Understanding where energy is produced, traded and consumed is therefore essential for interpreting global energy trends and assessing energy security.

Energy and greenhouse gas emissions

The production and use of energy are closely linked to greenhouse gas (GHG) emissions and climate change. Burning fossil fuels such as coal, oil and natural gas releases carbon dioxide (CO₂), while energy production and supply can also result in emissions of methane and other GHGs.  

Understanding these emissions alongside energy production and consumption helps show how changes in the global energy system affect its environmental impact. The Energy Institute Statistical Review of World Energy provides data on carbon emissions from energy use, alongside the data needed to examine how emissions vary between countries, fuels and over time.

Thinking like an analyst

Finding the right number is only the first step. The real value of the Statistical Review comes from understanding what the data are telling you. Competent analysts do more than report figures; they ask questions, compare different measures and check whether the results make sense.

A good place to start is by considering whether absolute change or percentage change tells the more useful story. A country that increases its wind generation by 20TWh over a particular period of time has added more electricity than one that increases by 5TWh; that is absolute change. However, if the second country started from a much smaller base, its percentage growth could be much higher than the larger country’s.

Context also matters. Large countries generally produce and consume more energy simply because they have larger populations and economies. Comparing total energy use between China and Poland, for example, tells you relatively little about how energy is used in each country. In many cases, it is more informative to compare data on a per person basis or alongside measures such as gross domestic product (GDP) to understand differences in energy intensity and economic development.

It is also important to distinguish between production and consumption. One country may produce large quantities of oil or natural gas but export much of it, while another may consume far more energy than it produces and therefore rely heavily on imports.  

Looking at production alone does not provide a complete picture of a country’s energy system. Analysts routinely compare production, consumption and trade data to understand where energy is produced, where it is used and how it moves around the world.

• Further reading: ‘Electrification and security: two big themes emerge from the latest Statistical Review of World Energy’. Discover the key findings of the 2026 Energy Institute Statistical Review of World Energy.