Solar power supplied a record 14.4% of Great Britain's electricity in July 2026, according to data from the National Energy System Operator (Neso), a 50% increase on the 9.6% share recorded in July 2025. The Guardian

The figure is the latest data point in what Frankie Mayo, a senior analyst at the clean power thinktank Ember, describes as the UK's "second solar boom." Official figures recorded 142,536 new solar installations in Great Britain in the first half of 2026, more than in any six-month period since 2011. Household rooftop systems account for slightly less than a third of total solar capacity, showing that both small-scale rooftop panels and large utility-scale solar farms are driving the current expansion.

On the utility side, the UK's largest operating solar project is Cleve Hill in Kent, at 373 MW (megawatts — a measure of power generation capacity). The country's first solar farm, the 1.4 MW Wheal Jane installation in Cornwall, has been dwarfed by orders of magnitude. Looking ahead, the Springwell solar farm in Lincolnshire, planned at 800 MW, is expected to begin generating in 2029, which would more than double the capacity of the current largest site. Chris Hewett, chief executive of the trade association Solar Energy UK, said solar is "now a major player in the UK electricity mix." The Guardian

Neso's data infrastructure reflects the growing significance of what's called "embedded generation" — electricity produced by smaller, distributed sources like rooftop panels that feed directly into local networks rather than through the main transmission grid. The operator publishes embedded wind and solar forecasts up to 14 days ahead on its data portal, noting that their effect is to suppress electricity demand during periods of high solar output. NESO Data Portal When rooftop and distributed solar reduces apparent grid demand, it directly affects balancing decisions (how the grid operator keeps supply and demand matched in real time), wholesale price formation, and the economics of running conventional power plants.

The trajectory is visible in earlier milestones. Neso's "Britain's Energy Explained: 2025 Review," published in January 2026, recorded maximum solar generation reaching 14,023 MW on 8 July 2025, with maximum wind generation hitting 23,825 MW on 5 December 2025. NESO Back in 2020, solar set records for both its highest generation level (9.7 GW) and its highest share in the electricity mix (34%), though that share figure reflected lower overall demand during pandemic lockdowns rather than the absolute generation levels seen now. NESO

Government deployment data aligns with the operator's generation figures. DESNZ's Energy Trends June 2026 publication reported UK renewable installed capacity at 66.0 GW, up 3.4 GW (5.4%) compared with the first quarter of 2025, with solar PV accounting for 2.4 GW of that new capacity. DESNZ Energy Trends, June 2026 The department's March 2026 publication had already recorded a new annual record for UK solar generation, up 37% to 20 TWh with a record 6.9% share of total generation, alongside 0.5 GW of newly installed capacity. DESNZ is also working to improve its tracking of installed solar capacity, as set out in a methodology update in the December 2025 Energy Trends publication, reflecting persistent challenges in monitoring distributed and behind-the-meter PV (panels connected on the customer's side of the meter, whose output the grid operator can't directly measure).

The UK picture fits a global pattern. In April 2026, wind and solar combined generated more electricity than gas worldwide for the first time, supplying 22% of global electricity compared with 20% from gas, according to Ember. Ember The International Energy Agency expects global solar PV generation to grow by an average of 24% per year, with solar's share of total generation reaching 10% in 2026 and approaching 18% by 2030. IEA

The broader context here is one of structural change in how Great Britain's electricity system is managed. Neso's connections reform timeline indicates that Phase 1 distribution connection offers are being processed between early July and mid-November 2026, a process aimed at clearing a backlog of renewable projects awaiting grid access. NESO The pace of that reform will materially influence whether the deployment trajectory visible in the first-half installation figures can be sustained through the back half of the decade.

There are also questions about the limits of what monthly share figures can convey. A 14.4% share in July, when demand is lower and solar irradiance peaks, does not translate linearly to winter months. Neso's monthly electricity reports, published on its energy stats page, will be the vehicle for tracking how the annual share evolves as more capacity comes online across seasons. NESO

What is clear is that the rate of change has accelerated. The jump from 9.6% to 14.4% year-on-year, combined with installation volumes not seen in fifteen years, places solar squarely in the tier of technologies shaping dispatch economics (which power plants get turned on and off, and in what order) and investment decisions in the British power market. Whether the pipeline, from rooftop installations to projects like Springwell, can continue to outpace grid-connection and planning constraints is the variable to watch.