Renewable energy solutions set new Q2 heights for UK electricity

The UK's transition to renewable energy solutions reached a major milestone in Q2 2025, as renewable electricity generation accounted for 56% of the country’s electricity mix - the highest share ever recorded for a second quarter, according to data from the Energy Dashboard ¹. Total renewable output stood at 29.7 TWh out of 52.8 TWh of overall generation.

Both wind and solar recorded their highest Q2 outputs, reflecting favourable weather conditions and continued capacity growth.

From a single source perspective:

• Wind - 17.6 TWh (dominant source)
• Solar - 7.2 TWh (record-breaking for Q2)
• Biomass - 4.5 TWh
• Hydro - 0.4 TWh

Renewables share of the UK power mix past 10 years - not including imports (TWh & %)

Sunniest spring on record sparks solar boom

In Q2 2025, the UK generated a record-breaking 7.2 TWh of electricity from solar power - marking a 32% increase compared to the same period in 2024 ¹.

Solar output increased significantly in late March and throughout April, driven by exceptionally sunny conditions. A total of 653 hours of sunshine was recorded across the quarter, 43% above the seasonal average, resulting in remarkable growth for renewable electricity generation.

According to the Met Office, spring 2025 was the sunniest on record since their data series began in 1910 ².

Carbon Brief’s analysis on UK solar generation saw that May 2025 set a new monthly record for solar generation in the UK, producing 2.5 TWh and contributing 11.6% of the nation’s electricity. At its peak on 6 April, solar power delivered 13.2 GW - meeting 40% of national demand in a single half-hour.

This solar surge, a key part of the UK’s renewable energy solutions, significantly reduced reliance on imported gas, offsetting around 16 TWh and saving an estimated £600 million. It also prevented 6 million tonnes of CO₂ emissions, equivalent to nearly 2% of the UK’s annual total.

The trend highlights the impact of both expanded solar capacity, now reaching 20 GW - and exceptionally positive weather, underscoring solar’s growing role in the UK’s energy mix ³.

2015 -2025 Solar Generation over the past 10 years

Curtailment challenges persist despite record Q2 wind output

Wind generation in Q2 2025 reached 17.4 TWh, setting a new second-quarter record and marking a 2% increase from Q2 2024 (17.0 TWh).

Despite consistently strong output throughout the quarter, curtailment remained a significant challenge for renewable electricity generation, particularly from late May through the end of June, when wind conditions were especially strong ⁴.

In the UK, our energy system occasionally shuts down wind turbines, even when they're generating a lot of clean, low-cost electricity. This is known as wind curtailment. It helps to stop the power grid from becoming overloaded, particularly in regions like Scotland during high wind speeds.

A notable curtailment event occurred on the night of 27 June, when approximately 7.5 GW of potential wind output was curtailed due to a combination of high wind generation and low electricity demand. This was one of the largest curtailment incidents recorded during the quarter.

On average, around 889 MW of wind capacity was bid down by the system operator, representing roughly 11% of total wind output. This suggests that, without transmission constraints, wind generation could have been up to 11% higher - highlighting the ongoing limitations of the UK’s grid infrastructure, and the need for more advanced renewable energy solutions to manage surplus generation.

Power generation by fuel type for Q2 past 10 years

Source - Energy Dashboard

Outlook in Q3

Q3 2025 began with unseasonably warm weather, with temperatures reaching 16°C by late June—well above the seasonal average. This early heatwave led to reduced electricity demand, while renewable energy solutions like solar and wind generation remained consistently strong.

According to Montel Analytics, this combination of low demand and high renewable output triggered a surge in negative electricity price events during Q2. If current trends persist, Q3 could surpass the 96 negative price occurrences recorded in the same period last year ⁶.

This underscores how intermittent renewables are reshaping the energy landscape and highlights the urgent need for a more flexible system to manage periods of surplus of renewable electricity generation.

Summary

In Q2 2025, the UK’s electricity sector continued its shift toward renewables, which accounted for a record 56% of the energy mix. Solar power surged to 7.2 TWh - up 32% year-on-year - thanks to the sunniest spring on record, while wind generation reached a Q2 high of 17.4 TWh despite significant curtailment due to grid constraints.

Imports remained steady at 10.8 TWh, mainly from France and Norway, supporting the grid during periods of low renewable output. Gas generation held at 14.0 TWh but continued its long-term decline, while nuclear output fell 12% due to maintenance outages. Biomass and hydro remained stable.

With Q3 starting warm and renewable energy solutions still strong, the energy market is facing more frequent negative pricing - highlighting the urgent need for a more flexible and resilient grid.

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In this article

• Renewable energy solutions set new Q2 heights for UK electricity
• Sunniest spring on record sparks solar boom
• Curtailment challenges persist despite record Q2 wind output
• Gas
• Imports
• Nuclear
• Hydro and Biomass
• Outlook in Q3
• Summary
• 100% renewable electricity for your business

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