IN Brief:
- Renewable sources supplied a record 55.8% of UK electricity generation in Q2 2026, producing 38.3TWh.
- Wind generated 19.2TWh and supplied 27.9% of electricity, exceeding gas generation's 26.8% share.
- Installed renewable capacity reached 66.3GW, 2.7GW above Q2 2025, with solar accounting for 2.1GW of the increase.
Department for Energy Security and Net Zero statistics show renewable sources supplied a record 55.8% of UK electricity generation during the second quarter of 2026, as stronger wind output and additional installed capacity pushed renewables above their previous quarterly high.
Renewable generation reached 38.3TWh between April and June, 5% higher than in the corresponding quarter of 2025. The 55.8% share exceeded the previous record of 54.8%, set in the third quarter of last year. DESNZ says the five most recent quarters are now the five highest renewable shares in the series.
Wind provided most of the increase. Combined onshore and offshore generation rose 9.4% to 19.2TWh and accounted for 27.9% of total electricity generation. That was higher than gas, which supplied 26.8% during the quarter.
Onshore wind generation increased 13% year on year, adding around 0.9TWh, while offshore wind rose 7.1%, adding roughly 0.7TWh. DESNZ attributes the stronger output to a combination of additional capacity and higher average wind speeds.
Solar generation reached 8.4TWh, matching the record established in the second quarter of 2025 even though sunshine hours were lower. The reason was capacity growth: the UK had added 2.1GW of solar over the intervening year, allowing a larger installed fleet to offset less favourable weather.
The comparison illustrates why installed capacity and electrical output have to be considered separately. More panels can increase the amount of energy captured under the same weather conditions, but generation remains tied to irradiation and time of day. The power system therefore has to manage greater daytime photovoltaic output without assuming that the same capacity is available through the evening peak.
DESNZ puts total installed renewable capacity at 66.3GW at the end of the quarter, 2.7GW or 4.2% higher than a year earlier. Solar accounted for around three quarters of that increase, with the rest coming from onshore wind, offshore wind, and energy from waste.
The quarterly additions were more modest than the annual number suggests. Approximately 0.4GW of new capacity was added between April and June, with the increase divided mainly between onshore wind and solar. That means the record generation share resulted from a combination of accumulated capacity growth and favourable wind conditions rather than an exceptional single quarter of construction.
Solar deployment has nevertheless reached substantial scale. UK installations passed two million earlier this year, with capacity already above 22GW by the end of March. Small rooftop systems dominate the installation count, while larger ground-mounted projects provide a substantial proportion of overall capacity.
That growth changes conditions beyond the generating plant itself. Distribution networks have to manage increasing levels of generation connected below transmission level, including reverse power flows, voltage changes, export constraints, and growing interaction between solar, batteries, electric vehicle charging, and other flexible loads.
The effect is also visible at system level. Recent analysis of Britain’s solar growth has highlighted the increasingly sharp transition between strong daytime renewable output and tighter evening conditions. Batteries, demand flexibility, interconnectors, and dispatchable generation all become more important as photovoltaic output falls after sunset.
Wind creates a different operating profile but the same requirement for flexibility. Output can remain high for much longer periods than solar, yet can also fall across large geographical areas during low-wind conditions. Additional turbines therefore reduce fossil generation when conditions are favourable without removing the requirement for resources capable of responding when renewable output changes.
The wider low-carbon share did not set a corresponding record because nuclear generation fell. DESNZ reports that nuclear output declined 11%, leaving low-carbon technologies with 68.5% of generation, 0.9 percentage points below the same quarter in 2025. Fossil generation increased 3.5% and supplied 27.2%.
That difference is useful because it prevents a record renewable percentage being treated as evidence that every low-carbon technology moved in the same direction. Electricity systems are portfolios: changes in nuclear availability, wind conditions, solar output, imports, gas operation, demand, and storage all alter the mix from one quarter to the next.
The renewable fleet is now large enough for those interactions to dominate the next stage of deployment. Another gigawatt of generation creates value only when network capacity, balancing resources, storage, controls, and demand can absorb its output when it is available and replace it when it is not.
A 55.8% quarterly share marks another record for renewable electricity, but the more important engineering figure may be the 66.3GW installed behind it. As that capacity continues to rise, Britain’s power programme is increasingly shifting from adding generation alone towards building the networks and flexibility needed to operate a system in which renewables regularly supply more than half of total electricity.
