By Thanasis Petras
International Correspondent | Chief Editor & Publisher — Diethni.gr
Renewable growth can reduce fossil fuels’ share of electricity without reducing their output. Evidence available at the beginning of 2026 shows where that distinction matters.
The world can build record amounts of renewable power and still burn more fossil fuel. This apparent contradiction becomes clearer when we distinguish between the size of the electricity system and the sources supplying it.
According to Ember’s Global Electricity Review 2025, renewables and nuclear supplied 40.9% of global electricity in 2024, up from 39.4% in 2023. Yet fossil electricity generation increased. Low-carbon sources gained market share, but growing electricity demand left room for fossil output to rise too.
Are renewables replacing fossil fuels? In some electricity systems and periods, the evidence shows replacement. Across the wider global energy system, however, renewable expansion had not yet produced a sustained decline in fossil fuel consumption.
Renewable growth and rising fossil generation
According to the International Energy Agency’s Global Energy Review 2025, global electricity demand increased by 4.3% in 2024. Renewables and nuclear supplied approximately 80% of the increase in electricity generation, but generation from natural gas rose by around 170 terawatt-hours and coal by around 90 terawatt-hours.
These observed changes explain why a rising low-carbon share did not produce an absolute decline in fossil electricity. Low-carbon sources supplied most of the additional generation, while coal and gas also increased their output.
The IEA identified rising cooling demand, industrial electricity consumption, electrification of transport and the expansion of data centres among the contributors to growing demand. Renewable expansion was substantial, but it did not cover the entire increase in electricity requirements.
Renewables overtook coal in early 2025
Ember’s Global Electricity Mid-Year Insights 2025 reported that renewable generation increased by 363 terawatt-hours compared with the first half of 2024, reaching 5,072 terawatt-hours. Coal generation fell by 31 terawatt-hours to 4,896 terawatt-hours.
Renewables supplied 34.3% of global electricity, exceeding coal’s 33.1%.
Renewables moved from producing less electricity than coal to producing more. Most of that shift reflected renewable expansion, rather than coal’s comparatively small decline.
Two distinct developments occurred: renewables overtook coal, and coal generation fell in absolute terms. Neither establishes that all fossil electricity declined, because gas and oil must also be counted. Nor does a six-month comparison establish a lasting trend.
Europe’s electricity mix shows a deeper shift
The European Union provides a longer-term example.
In its European Electricity Review 2024, Ember reported that EU coal generation fell by 327 terawatt-hours between 2016 and 2023, while wind and solar generation increased by 354 terawatt-hours. These changes are consistent with substantial substitution, although their similar size does not establish a one-for-one causal relationship.
In 2024, EU solar generation reached 304 terawatt-hours, overtaking coal’s 269 terawatt-hours. Solar supplied approximately 11% of electricity, compared with coal’s 10%, according to Ember’s European Electricity Review 2025.
Solar’s lead is not a measure of the coal it displaced. Additional renewable electricity can replace gas, meet growing demand or change cross-border flows. Coal generation can also decline because of greater nuclear availability, recovering hydropower or lower consumption.
Assessing replacement requires following the whole electricity balance.
Installed capacity is not electricity generated
Installed capacity describes how much power equipment can produce under specified conditions. Generation describes the electricity it actually delivers over time.
The IEA reported that around 700 gigawatts of renewable capacity were added globally in 2024, with solar photovoltaic installations accounting for nearly 80% of the additions. Separately, it reported that electricity generation from solar and wind increased by a combined 670 terawatt-hours.
These are different measurements: gigawatts describe installed power capacity, while terawatt-hours describe electricity generated over time. Actual generation depends on resource availability, operating conditions and access to the grid. Capacity announcements alone therefore cannot establish how much fossil generation has been displaced.
Equally, a fossil plant can remain open while operating fewer hours and consuming less fuel. Plant counts and construction announcements therefore reveal less about displacement than generation and fuel consumption.
Electricity is only part of the transition
Cleaner electricity does not automatically replace the oil burned by aircraft or the gas consumed directly in buildings and factories.
Electrification connects changes in electricity supply with these other uses. Electric vehicles can replace petrol consumption; heat pumps can replace fuel combustion for heating. The emissions outcome depends partly on how their electricity is generated.
These technologies also change energy requirements. Combustion involves conversion losses, while electric technologies can deliver the same service with less energy input. Replacing fossil fuels does not necessarily require an equal quantity of renewable electricity.
The useful comparison is therefore between services delivered, fuels consumed and emissions produced.
The broader global record remained one of expansion in 2024. The IEA reported that total energy demand increased by 2.2%, with oil, gas and coal demand all rising. Progress in electricity had not yet produced a decline across the wider energy system.
Progress has not yet become a sustained global decline
The available data show that renewable expansion was changing electricity supply. Coal generation declined globally in the first half of 2025, while renewable generation grew. In the European Union, solar generated more electricity than coal in 2024.
These developments should be assessed alongside the wider energy figures. The IEA’s Global Energy Review 2025 reported that global oil demand increased by 0.8% in 2024, natural gas demand by 2.7% and coal demand by 1%. Progress in electricity was therefore occurring alongside increasing fossil fuel consumption across the economy.
The evidence supports a qualified answer: renewables are contributing to fossil displacement in some electricity systems and periods, while also supplying growing demand. By the beginning of 2026, that progress had not established a sustained decline in global fossil fuel consumption.
Assessing the transition requires tracking electricity generation, direct fuel consumption and emissions together. Renewable growth is an important part of the story; whether fossil use actually falls is the decisive outcome.
Sources
- International Energy Agency, Global Energy Review 2025.
- Ember, Global Electricity Review 2025.
- Ember, Global Electricity Mid-Year Insights 2025.
- Ember, European Electricity Review 2024.
- Ember, European Electricity Review 2025.
