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). That's a 50% jump from the 9.6% share recorded in July 2025. The Guardian

The figure is the latest sign of what Frankie Mayo, a senior analyst at the clean power thinktank Ember, calls the UK's "second solar boom." Official figures recorded 142,536 new solar installations in Great Britain in the first half of 2026. That's more than in any six-month period since 2011. Household rooftop panels account for slightly less than a third of total solar capacity, meaning both home systems and large solar farms are driving the growth.

On the large-farm side, the UK's biggest operating solar project is Cleve Hill in Kent, rated at 373 MW (a megawatt, or MW, is a unit of power generation capacity). The country's first solar farm, the 1.4 MW Wheal Jane installation in Cornwall, is tiny by comparison. Looking ahead, the Springwell solar farm in Lincolnshire, planned at 800 MW, is expected to begin generating in 2029. That 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 systems reflect the growing role of "embedded generation" — electricity produced by smaller, local sources like rooftop panels that feed into neighborhood power lines rather than the main national grid. The operator publishes forecasts for this kind of solar and wind up to 14 days ahead on its data portal, noting that high solar output reduces the amount of electricity the grid needs to supply. NESO Data Portal This matters: when rooftop panels reduce the demand seen on the grid, it affects how operators balance supply and demand, how electricity prices are set, and whether conventional power plants need to run.

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 of the electricity mix (34%). But that share figure was partly inflated by lower overall electricity use during pandemic lockdowns, rather than reflecting the generation levels seen now. NESO

Government data lines up with the operator's figures. DESNZ (the Department for Energy Security and Net Zero) reported in its June 2026 Energy Trends publication that UK renewable installed capacity reached 66.0 GW, up 3.4 GW (5.4%) compared with the first quarter of 2025, with solar 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 (a terawatt-hour is a unit of energy, roughly enough to power about 300,000 UK homes for a year) with a record 6.9% share of total generation, alongside 0.5 GW of newly installed capacity. DESNZ is also working to improve how it tracks installed solar, as set out in a methodology update in the December 2025 Energy Trends publication, because counting panels on rooftops that connect on the customer's side of the meter has been persistently difficult.

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 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 big changes 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. This process is aimed at clearing a backlog of renewable projects waiting for permission to connect to the grid. NESO The pace of that reform will materially influence whether the growth seen 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 a single month's figures can tell us. A 14.4% share in July, when electricity demand is lower and sunlight is at its peak, does not translate to winter months. Neso's monthly electricity reports, published on its energy stats page, will be the way to track how the annual share evolves as more solar 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 among the technologies shaping electricity prices 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.