The year 2025 was paradoxical for British electricity: renewable sources broke records, but at the same time, gas production increased. Coal no longer contributed to the energy mix at all (for the first time in more than a century). The result is a mix that is greener than ever before, but in practice is coming up against the limits of the grid, the availability of nuclear power, and growing demand.
Numbers worth paying attention to
According to data analysis (NESO, DESNZ), the following applies for 2025:
- Electricity demand: 322 TWh (+1%) – second consecutive increase after years of decline.
- Total renewable sources: 152 TWh (+6%) and a record share of 47% of electricity supply.
- Gas: 91 TWh (+5.8%) and a 28% share.
- Nuclear: only 36 TWh (a decline of -12%), the lowest level in “half a century” due to shutdowns/maintenance.
- Coal: 0 TWh (still approx. 2 TWh in 2024).
And now an interesting detail: even though production from renewable sources has increased and coal is no longer used in production, carbon production has risen slightly to 126 gCO₂/kWh (from a record low of 124 g in 2024). This can be attributed primarily to the shutdown of nuclear power plants and the coverage of these sources by gas-fired power plants.
Records: wind, solar, biomass
The year 2025 brought new annual production records:
- Wind: 87 TWh (+5%)
- Solar: 19 TWh (+31%)
- Biomass: 41 TWh (+2%)
- In the case of solar, a combination of higher installed capacity and weather conditions helped – 2025 was exceptionally sunny in the UK (which was reflected in production).
Why did gas prices rise when renewable energy sources also grew?
- Because several things happened at once:
- The end of coal
- A weaker nuclear sector – shutdowns created a gap in supply that someone had to fill.
- Growing demand – the electrification of transport and heating + data centers are starting to show up in the numbers.
- Increased energy sales abroad
In other words: RES supplied a record amount of energy, but backup and infrastructure are still pushing the envelope.
What to take away from this (even outside the UK)
A record high in renewable energy ≠ automatically less gas. If nuclear/coal power fails and consumption rises, gas plays a balancing role in the grid when no other energy is available.
Solar energy is an important part of the energy mix
Electrification is beginning to change the demand trend.
Sources:
