
The UK's Electricity Mix: What Powers Our Homes?
Jan 30
3 min read
In September 2024, the UK closed its last remaining coal power plant, marking the end of coal's 142-year dominance in British power generation. Just 30 years ago, coal provided 45% of our electricity - today, that figure is zero. So what are the sources of power in the UK’s electricity mix?
The short answer is that most of our electricity is provided by clean sources of generation - a larger proportion than what most people think. Renewable energy now generates over 46% of our annual electricity, and when you include nuclear power, over 60% comes from carbon-free sources, with the rest met by natural gas plants and imports of electricity from neighbouring countries using undersea cables. In fact, 2024 marked a historic milestone: wind power overtook gas as our largest source of electricity for the first time.

But our electricity mix isn't static - it changes dramatically throughout the day and across seasons. Here's what influences these changes:
Daily Patterns
Most homes use more electricity in the morning (think showers and breakfast) and early evening (dinner time and entertainment). These predictable peaks currently require quick-starting gas power plants to meet the surge in demand. In time more renewable energy capacity, combined with greater availability of energy storage from large batteries and pumped hydro, will reduce the role that gas currently plans.
Seasonal Changes
Winter brings both challenges and opportunities. While solar output drops significantly, wind generation typically increases. However, electricity demand also rises due to increased lighting needs and electric heating, often requiring more gas power and imports to fill the gap.
Weather Impact
The weather has a huge effect on our power mix. On windy days, wind farms can provide up to 54% of our electricity - a figure that will continue to go up every year. Meanwhile, sunny summer days boost solar output - though interestingly, solar panels actually perform better at temperatures below 25°C.
Market Forces
Most renewable energy is secured through long-term government contracts, meaning it will always be utilised by the grid operator, unless there are transmission bottlenecks. When gas prices are high, we tend to import more electricity from countries like France and the Netherlands through undersea cables - and battery storage is likely to kick in. Unfortunately our ability to substitute for gas generation is quite limited, which explains why gas prices are driving the high cost of electricity.

As you may imagine, the makeup of our electricity generation has a big impact on its carbon intensity. If you are curious to check the breakdown of generation sources at any moment in time, we recommend this website or this app.
Looking ahead, the National Energy System Operator (NESO) is planning for an even greener future, with renewable energy set to grow significantly by 2030. Traditional gas generation is predicted to shrink to just 5% of annual electricity demand over a typical weather year, eventually getting called only on certain days. Enabling this will require a big increase in energy storage and demand flexibility to help manage the daily fluctuations in demand and supply under a more variable system.
This shift away from fossil fuels represents one of the fastest energy transitions in the world - and it's happening right here in the UK.