Global Energy by Source: Fossil Fuels Still Supply 86%

Overview

Global primary energy consumption passed 600 exajoules in 2025, up 1.7% on the year. The composition of that total is the part most often reported inaccurately.

Oil supplied roughly a third at about 201 exajoules, followed by coal at about 166 and natural gas at about 151. Together the three fossil fuels accounted for around 86% of world energy — a share that has moved remarkably little despite two decades of renewable deployment.

Nuclear contributed about 5.2%. Renewables including solar, wind, geothermal and biofuels made up about 5.9%, with hydropower a further 2.7%. Solar reached roughly 10.12 exajoules and wind 9.77 — about 3.3% of world energy between them.

The finding that most complicates the usual narrative is this: renewables were the largest single contributor to energy growth in 2025, adding 3.3 exajoules — and global energy-sector CO2 emissions still rose 1.1%, to about 35.8 billion tonnes. Understanding why requires looking at growth rather than share.

Fossil Fuels Still Supply 86% of World Energy

The headline number is the one most likely to surprise anyone following renewable energy coverage. After decades of deployment, falling costs and policy support, oil, coal and gas still supply approximately 86% of global primary energy.

This is not a contradiction of renewable growth — that growth is real and is documented below. It is a statement about scale. The global energy system is enormous, and the fossil infrastructure built over a century does not shrink because newer capacity is being added elsewhere.

It is also worth being precise about what 'primary energy' means. It counts all energy entering the system, including the substantial portion lost as waste heat when fossil fuels are burned in thermal power plants. Because renewables and nuclear have different conversion characteristics, comparisons need care — a point returned to later in this piece.

The share is what it is regardless. Fossil fuels remain the foundation of the world energy system, and any analysis that implies otherwise is describing an aspiration rather than the current data.

Oil, Coal and Gas: The Actual Split

Within the fossil total, the three fuels are closer in size than most people expect, and their roles are quite distinct.

Oil is largest at roughly 201 exajoules, about a third of world energy. Its dominance rests on transport, petrochemicals and heavy industry — applications where energy density and existing infrastructure make substitution genuinely difficult, whatever the pace of electric vehicle adoption.

Coal follows at about 166 exajoules, roughly 27.6%. It is concentrated in electricity generation and heavy industry, particularly steel and cement, where the chemistry as well as the heat is hard to replace.

Natural gas is third at about 151 exajoules, roughly 25.1%. It is often framed as a transition fuel because it emits less CO2 per unit of energy than coal, though methane leakage across the supply chain reduces that advantage by an amount that remains contested.

Coal Was Supposed to Be Declining

Coal's position is the single most awkward fact in the global energy picture, and it is worth stating without softening.

Coal is the most carbon-intensive major fuel and the most direct target of climate policy. It has been the subject of phase-out commitments, financing restrictions and retirement schedules across many countries for over a decade.

Coal consumption nevertheless rose again in 2025, adding about 1.1 exajoules. It remains the world's second-largest energy source at roughly 27.6% of the total.

The explanation is largely geographic. Coal use has genuinely declined across much of Europe and North America. It has grown in Asian economies where electricity demand is rising quickly and coal is the cheapest domestically available option. Those two trends have not cancelled out — the growth has been the larger of the two.

Renewables Grew Fastest, and Emissions Still Rose

Both halves of this section's heading are drawn from the same dataset, and holding them together is essential to reading the energy transition accurately.

Renewables — solar, wind, geothermal and biofuels — were the largest single source of energy supply growth in 2025, adding 3.3 exajoules. That exceeded the growth of oil at 2.5, gas at 2.4 and coal at 1.1. On the margin, renewables are winning.

Global CO2 emissions from the energy sector nonetheless rose 1.1%, reaching approximately 35.8 billion tonnes. Total emissions including non-energy sources reached around 41 billion tonnes, also up 1.1%.

There is no inconsistency here, and the reconciliation is the most important idea in this article. Renewables grew faster than any other single source — but total demand grew faster than renewables alone could cover.

The Addition Problem

Total primary energy grew 1.7% in 2025, an increase of roughly ten exajoules on a base above 600. Renewables supplied 3.3 of that increase.

The remaining growth was met largely by fossil fuels, which added roughly six exajoules between oil, gas and coal. New renewable capacity was therefore absorbed by new demand rather than replacing existing fossil generation.

This is the central dynamic of the current transition. Renewables are being added to the energy system rather than substituting within it, which is why record deployment coexists with rising emissions. Emissions fall when low-carbon sources displace fossil generation, not merely when they grow.

The implication is arithmetic rather than ideological. For emissions to decline, renewable growth must exceed total demand growth — and until it does, faster deployment slows the increase without reversing it.

Solar and Wind: 3.3% Combined

Solar and wind attract the majority of energy transition coverage, which makes their actual share worth stating plainly.

Solar reached about 10.12 exajoules in 2025, roughly 1.7% of global primary energy. Wind reached about 9.77 exajoules, roughly 1.6%. Together they account for around 3.3% of world energy consumption.

That figure invites two readings, and both are correct. It is small — smaller than most people assume given the volume of attention. It is also growing faster than anything else in the system, from a base that was negligible fifteen years ago.

The constraint is no longer primarily cost. Solar and wind are now the cheapest new generation in many markets. The binding constraints have shifted to grid capacity, connection queues, permitting timelines and the storage needed to manage output that varies with weather.

Nuclear's Quiet 5.2%

Nuclear supplies about 5.2% of global primary energy — more than solar and wind combined, with a fraction of the coverage.

Its distinguishing characteristic is that it provides firm low-carbon power. Output does not depend on weather or time of day, which means it can supply baseload demand without the storage or backup capacity that variable renewables require.

Output grew modestly in 2025, adding about 0.4 exajoules. Growth is constrained less by the technology than by construction economics: large reactors have consistently run over budget and behind schedule in Western markets, though build times in parts of Asia have been considerably shorter.

Small modular reactors are the frequently cited answer to that problem. They remain largely pre-commercial, and the honest position is that their economics will be established by operating units rather than by projections.

Hydropower: The Renewable That Can't Scale Much Further

Hydropower supplies about 2.7% of global primary energy, making it the largest single renewable source — ahead of solar and ahead of wind.

It is also the most mature. Hydropower has been generating at scale for over a century, and the largest facilities are among the biggest power stations of any kind ever built.

Its limitation is physical rather than technological. Hydropower requires suitable river geography, and in most developed economies the viable sites have been developed. Growth in 2025 was about 0.1 exajoules, the smallest increase among major sources.

Climate change adds a further complication that is easy to overlook: hydropower output depends on rainfall and snowmelt, and drought has reduced generation in several major hydro-dependent regions in recent years. It is a renewable source that is itself exposed to the climate.

Why Different Sources Give Different Numbers

Readers comparing energy statistics across publications will find figures that disagree, sometimes substantially. This is usually a question of accounting method rather than data quality, and it is worth understanding.

The difficulty is that fossil fuels are burned to produce heat, most of which is wasted — a coal plant may convert only around 40% of the fuel's energy into electricity. Renewables and nuclear produce electricity more directly.

Counting the raw energy input treats a unit of coal energy and a unit of solar electricity as equivalent, understating renewables relative to the useful energy they deliver. The alternative 'substitution method' scales non-fossil electricity up to reflect the fossil fuel that would have been needed to generate it, producing notably higher renewable and nuclear shares.

Neither approach is wrong; they answer different questions. The figures in this article follow a consistent set from a single source for the same year, which is the practical requirement — a mix of methods produces shares that do not sum correctly and comparisons that do not hold.

What the Trend Line Actually Shows

Pulling the data together produces a picture that fits neither of the usual narratives about the energy transition.

The pessimistic reading — that renewables are not working — is contradicted by the growth figures. Renewables added more energy supply in 2025 than any other single source, and solar and wind costs have fallen far enough to make them the default choice for new generation in many markets.

The optimistic reading — that the transition is well underway — is contradicted by the share figures. Fossil fuels remain at about 86%, coal grew again, and energy-sector emissions rose 1.1% to roughly 35.8 billion tonnes.

The accurate summary sits between them and is less satisfying than either. A transition is genuinely happening at the margin, in new capacity, while the installed base changes slowly. The measure worth watching is not renewable deployment in isolation but renewable growth against total demand growth — because that difference, and not the deployment figure, is what determines whether emissions rise or fall.

Conclusion

Global primary energy passed 600 exajoules in 2025, and fossil fuels supplied about 86% of it — oil at roughly 201 exajoules, coal at 166 and gas at 151. Nuclear contributed 5.2%, renewables 5.9% and hydropower 2.7%, with solar and wind together at about 3.3%.

Renewables were the largest single source of growth, adding 3.3 exajoules and outpacing oil, gas and coal individually. On the margin, low-carbon energy is winning the competition for new supply.

Emissions nonetheless rose 1.1% to approximately 35.8 billion tonnes, because total demand grew by around ten exajoules while renewables supplied 3.3 of them. New clean capacity met new demand instead of displacing existing fossil generation.

That is the transition's actual state: real and accelerating in new capacity, slow in the installed base. Emissions begin to fall when low-carbon growth exceeds total demand growth — and in 2025 it did not.

Data Source and Attribution

Energy Institute Statistical ReviewStatistical Review of World Energy 2026Our World in Data (Energy)

All energy shares, exajoule figures, growth rates and emissions totals for 2025 come from the Energy Institute Statistical Review of World Energy 2026 (74th edition series), published July 2026: total primary energy above 600 EJ (+1.7%); oil approximately 201 EJ, coal 166 EJ, gas 151 EJ; fossil fuels approximately 86% of total energy supply; nuclear 5.2%, renewables 5.9%, hydropower 2.7%, solar 1.7% (10.12 EJ), wind 1.6% (9.77 EJ); growth of oil +2.5 EJ, gas +2.4 EJ, coal +1.1 EJ, nuclear +0.4 EJ, hydro +0.1 EJ, renewables +3.3 EJ; energy-sector CO2 emissions of 35,806.2 million tonnes (+1.1%) and total emissions of approximately 41,000 million tonnes.

FactsFigs reviews, cleans, and cross-checks every source dataset before shaping it into a data story. Each visualization is created and designed in FactsFigs Design Studio — an internal tool developed and owned by FactsFigs — and is the original work of a FactsFigs author, not an AI-generated copy of any existing graphic. Individual assets within a visual may or may not be produced with AI tools, but the design of the visual itself is solely FactsFigs' own.

Percentage shares are rounded and drawn from a single consistent source and year. Primary energy accounting methods differ between publications, as explained in the article, so figures here should not be mixed with shares calculated on a different basis.

2026-07-20