Carbon Brief recently conducted an analysis revealing that fossil fuels accounted for a record-low 2.4% of electricity on Great Britain’s island for one hour on April 15th. This analysis highlights the progress made by the National Grid Electricity System Operator (NGESO) towards achieving its target of “zero carbon operation” for short periods by 2025.
However, despite the increasing frequency of periods with minimal electricity from fossil fuels, there are still instances where gas power remains crucial for the GB grid. In fact, during a few hours in January, fossil fuels supplied around 66% of the demand. So, is the GB grid becoming less reliant on fossil fuels or not?
Examining snapshots from short periods fails to provide a comprehensive view of the situation. Even annual averages mask the variability caused by the growing reliance on weather-dependent renewables like wind and solar power.
To provide a more complete picture, Carbon Brief created a figure resembling Joy Division’s iconic “Unknown Pleasures” album cover. This figure illustrates the distribution of half-hour periods since 2009 based on the share of fossil fuels during each period. The periods where fossil fuels accounted for more than 50% are shaded red, while those with less than 50% are shaded blue.
The figure demonstrates a significant shift away from fossil fuel reliance over the past 15 years. The entire distribution of half-hour periods has moved away from fossil fuels, with both the maximum and minimum extremes decreasing. For instance, in 2009, every half-hour period relied on fossil fuels by at least 50%, whereas in 2024, nearly 92% of periods had less than 50% reliance on fossil fuels.
Additionally, there has been a widening of the range between the maximum and minimum fossil fuel share. While fossil fuels are still essential for maintaining secure electricity supplies, they are becoming increasingly uncommon as the country progresses towards the government’s target of a “fully decarbonised” grid by 2035.
This shift underscores the need for flexible low-carbon alternatives that can be deployed for short periods. While achieving a record-low fossil fuel share is a significant achievement, reaching the 2035 target will require substantial further progress.
