The generation mix right now: more than half is renewable

In 2024, UK renewable energy sources produced 50.8% of the country's electricity for the first time. That landmark figure comes from Ember and RenewableUK, and it represents a genuine turning point in British energy history. In 2010, renewables covered less than 7% of UK generation. The transformation has been rapid and is still accelerating.

Here is how the 2024 generation mix breaks down:

Source Share of UK electricity Type
Wind (offshore + onshore)~29.9%Renewable
Nuclear~15%Low-carbon (not renewable)
Gas (CCGT)~25%Fossil fuel
Biomass~6%Low-carbon (debated)
Solar~5.5%Renewable
Hydro~2%Renewable
Imports + other~17%Mixed

The 50.8% renewable figure includes wind, solar, hydro, and biomass. Exclude biomass and you get to roughly 37% from purely intermittent and hydro renewables. Add nuclear and the low-carbon share reaches approximately 52% of UK generation. Gas, once dominant, now covers around 25% and is in structural decline.

The UK has committed to net zero by 2050 and to a clean power system by 2030. Both targets require the grid to run on low-carbon sources for 95%+ of electricity generation. The infrastructure to get there is already being built.

Wind: the UK's biggest source of electricity

Wind delivered approximately 30% of UK electricity in 2024, according to Carbon Brief and Ember. That makes it the single largest source of UK electricity, ahead of gas for the first time. On good windy days, wind routinely covers 50-60% of national demand. During strong storms, it has exceeded 70%.

The UK is among the windiest countries in Europe. Its geography is exceptional for wind: long Atlantic coastlines, a shallow North Sea shelf ideal for offshore foundations, and prevailing westerly winds that blow with reasonable consistency through the year. This is not luck. It is the physical reason the UK became a world leader in wind energy rather than solar or hydro.

Wind generation has a critical timing characteristic that directly affects Agile prices. Wind turbines generate electricity based on weather, not on demand. At 2am on a blustery night in January, wind output can be at its daily peak while household demand is at its annual low. The result: surplus electricity, low wholesale prices, and cheap Agile half-hours for anyone awake enough to notice.

This is the fundamental mechanism behind why cheap electricity is green electricity. The grid's cheapest moments are its greenest moments. Understanding where wind fits in the generation mix makes that connection visceral rather than abstract.

Offshore vs onshore wind: why the UK leads the world

The UK operates the largest offshore wind fleet in the world, with over 14GW of offshore capacity installed by 2026. For context, Germany is second with around 8GW. The scale of the UK's offshore ambition is genuinely without precedent.

Offshore wind produces approximately 40% more energy per MW of installed capacity than onshore wind. The reason is physics: offshore winds blow harder, more consistently, and without the turbulence created by hills, trees, and buildings. A 1MW offshore turbine generates around 3,500-4,000 MWh per year. A 1MW onshore turbine generates around 2,200-2,800 MWh. Over a 25-year operational life, the difference in output is enormous.

Offshore is also more expensive to build and maintain. Salt water, remote locations, and deep foundations all add cost. But the economics work out: the higher capacity factor more than compensates for higher capital expenditure, and the UK's shallow continental shelf makes foundation installation more practical than for most countries.

The flagship project is Dogger Bank, being built 130km off the Yorkshire coast. When complete, Dogger Bank A, B, and C will have a combined capacity of 3.6GW, making it the largest offshore wind farm in the world. At full output, it will power over 4.5 million homes.

Onshore wind was effectively banned in England between 2015 and 2023 due to planning restrictions. That policy has reversed, and new onshore developments are now underway. Scotland never had the same restrictions and has consistently built onshore capacity. Scotland's wind generation regularly exceeds 100% of its own electricity demand on good days, with the surplus exported south.

Solar's seasonal impact: summer champion, winter bit-part

The UK has around 20GW of installed solar capacity in 2026, spread across large solar farms and approximately 1.5 million rooftop installations. Solar is the fastest-growing renewable technology by installed units, and costs have fallen by over 90% since 2010.

But solar in the UK has a fundamental limitation: it is intensely seasonal. A 1kW solar panel system generates approximately:

Annual output for a 1kW system is around 850 kWh per year in the UK, compared to 1,200-1,400 kWh in southern Spain. The UK is not a solar-first country. But 20GW of even seasonal solar capacity adds up to a meaningful contribution in spring and summer.

For Agile users, solar creates a second type of cheap window: midday dips in summer months. When solar generation peaks (11am-3pm on sunny days), wholesale prices often fall sharply. These midday windows are less predictable than overnight wind windows but are increasingly common in April through September.

Solar has no overnight impact whatsoever. After sunset, every kilowatt of electricity comes from wind, nuclear, gas, hydro, or imports. This is why the overnight window remains the most reliable cheap period on Agile year-round, not just in summer.

The baseload problem: what solves the variability challenge

Wind and solar are variable. They generate electricity when the weather cooperates, not when the kettle is switched on at 6pm. This variability is the central engineering challenge of the modern grid, and it is worth understanding clearly rather than dismissing or overclaiming.

The UK grid must balance supply and demand at all times. The system frequency is held at 50Hz. If supply exceeds demand, frequency rises. If demand exceeds supply, frequency falls. Large deviations from 50Hz damage equipment and, in extremis, cause blackouts. Balancing the grid with 30-50% intermittent generation requires tools and flexibility that a fossil-fuel-dominated grid never needed.

Nuclear provides the closest thing to a solution on the generation side. The UK's nuclear fleet contributes around 7GW of constant baseload power, running at 90%+ capacity 24 hours a day regardless of weather. Nuclear power is not renewable, but it is reliably low-carbon and provides the stable backbone that allows more intermittent renewables to function without the grid collapsing.

Gas fills the gaps that nuclear cannot. When wind drops and solar is absent, gas turbines ramp up within minutes to meet demand. Gas is the swing source: flexible, responsive, but carbon-intensive. Reducing the UK's gas dependency requires either more storage, more demand flexibility, or more interconnector capacity, ideally all three.

Interconnectors: buying and selling electricity across Europe

The UK is not an energy island. Eight or more high-voltage undersea cables connect the British grid to neighbouring countries, allowing electricity to flow in both directions depending on supply and demand conditions.

Key interconnectors include:

Total interconnector capacity is approximately 8GW in both directions. When the UK has surplus wind at night, it can export that electricity to France or Belgium. When wind drops and the UK needs power, it can import from Norway's hydro reservoirs, which function as vast natural batteries.

Interconnectors are one of the reasons the clean energy transition is more viable than sceptics claim. The UK grid is not a closed system. It is part of a continental network. Surplus from one country balances deficit in another, and that exchange is governed by price signals that look remarkably like Agile half-hourly pricing at a European scale.

Storage: batteries and pumped hydro

The simplest solution to renewable variability is storage: charge when electricity is cheap and plentiful, discharge when it is expensive and scarce. The UK has two main storage technologies operating at scale today.

Pumped hydro is the largest form of grid storage in the UK by capacity. Dinorwig power station in Snowdonia, Wales, can generate 1.8GW by releasing water stored in an upper reservoir into a lower lake through turbines. It can reach full output in under 12 seconds, making it invaluable for grid emergencies. Cruachan in Scotland adds another 400MW. Both facilities were built during the nuclear era to absorb overnight baseload surplus. Today they serve the same function for overnight wind surplus.

Grid-scale batteries have grown from a standing start in 2016 to over 3GW of installed capacity in 2026, with more under construction than in any other European country. These lithium-ion installations charge during low-price windows (overnight, during plunge pricing events) and discharge at peak demand periods. They are also used for grid balancing, responding to frequency deviations in milliseconds.

For Agile users, the growth of storage matters for two reasons. First, batteries absorb more surplus renewable electricity, reducing curtailment and keeping overnight prices low. Second, they provide peak demand support that would otherwise require gas peakers to run, keeping peak Agile prices in check. More storage is unambiguously good for smart tariff users.

The 2030 clean power mission: what it means for Agile

The UK government's clean power mission targets 95% of electricity from low-carbon sources by 2030. That means roughly four years of intensive infrastructure build. The pipeline includes:

For Octopus Agile users, the trajectory is straightforward. More renewable generation means more surplus at off-peak times. More surplus means lower overnight prices. More frequent negative pricing events. A wider spread between peak and off-peak rates. The Agile tariff becomes more valuable, not less, as renewable penetration rises.

In a grid with 95% clean power, the overnight window becomes even more reliably cheap and green. An EV charged at 2am in 2030 will consume electricity that is essentially carbon-free, and it will cost a fraction of what peak electricity costs. The direction of travel is clear, and it rewards households who build flexible habits now.

You can track where the UK grid is right now, including which renewable sources are generating, through AgileAlert's live price dashboard. When Agile prices drop overnight, that is the renewable surplus making itself visible in your electricity bill.

Read more about why cheap electricity is the greenest electricity, and how timing your usage to low-price windows contributes directly to the clean energy transition.

Frequently asked questions

Did renewables really hit 50% of UK electricity?
Yes. In 2024, renewable sources generated 50.8% of UK electricity according to Ember and RenewableUK. This includes wind, solar, hydro, and biomass. It is the first full year in which renewables exceeded fossil fuels as a share of UK generation. Wind alone contributed approximately 30% of UK electricity in 2024.
Why does the UK have so much offshore wind?
The UK has a shallow continental shelf, strong and consistent Atlantic winds, and a long coastline. These physical advantages made offshore wind economically viable earlier and at greater scale than in most other countries. Government support from the early 2010s, combined with dramatic cost reductions from scale, made the UK the world leader. By 2026, UK offshore capacity exceeds 14GW, well ahead of any other country.
Does more renewable energy mean lower Agile prices?
Generally, yes. Renewable energy has near-zero marginal cost once the infrastructure is built. High renewable output suppresses wholesale electricity prices, particularly overnight when demand is low. More wind and solar capacity means more surplus periods, which translates to lower off-peak Agile prices, more frequent plunge pricing events, and a wider gap between cheap and expensive half-hours. The Agile tariff gets more rewarding as the grid gets greener.
Is nuclear power renewable?
Nuclear power is not classed as renewable because it relies on finite uranium fuel. However, it is low-carbon: nuclear generates roughly 12g of CO2 per kWh over its lifecycle, comparable to wind and solar. In the context of the UK's clean power target, nuclear is a critical low-carbon baseload source. The UK's existing fleet provides around 7GW of constant generation, providing the stable foundation that allows intermittent renewables to function without grid instability.
When will the UK reach its clean power target?
The UK government targets 95% clean electricity by 2030. That requires roughly doubling current wind capacity and tripling solar capacity within four years. Most analysts consider it achievable but challenging, dependent on faster grid connection processes, planning reform, and sustained investment. Even if the 2030 date slips slightly, the direction is clear: the UK electricity mix will be overwhelmingly low-carbon well before 2035.