In this article, Josh Cornes, solar analyst at Solar Media Market Research, outlines his prediction for how the UK solar market will develop in 2026. He discusses the added capacity and some of the challenges developers may face.
The UK solar market is expected to grow 50% year-on-year for the second year in a row, and is expected to add 5-5.5 GWp-dc of capacity by 2026, comfortably its best year on record.
The market grew by 50% year-on-year by 2025 (as predicted at the beginning of the year), bringing the total capacity past 23 GWp with 3.5 GWp added. Growth in 2025 was largely driven by ground installation, with nearly double the number of installations in that segment than in 2024.
Residential rooftops also had a good year, with more than 650 MW added. helped by the number of initiatives introduced and proposed by the government over the past twelve months.
In 2024, ground mounting represented 60% of total capacity, increasing to 70% by 2025, continuing the trend of ground mounting becoming increasingly important in the market and expected to continue to grow year-on-year. Residential roofs accounted for 18%, while commercial roofs accounted for the remainder. The residential roofing market had its best year ever, up 25% year-on-year.
Figure 1 shows the significant amount of solar added by 2025, as well as the significant increase in ground-mounted solar. Rooftop has been stable over the past five years, with 2026 set to be somewhat unpredictable due to the aforementioned number of initiatives the Labor government continues to bring in.
Figure 1: Cumulative solar capacity and added capacity per year. The lines highlight the growing importance of ground mounting as it continues to account for a larger share of added capacity on an annual basis.
Excluding Cleve Hill Solar Farm, half of the remaining capacity came from just four developers, one of which completed 350 MWp.
Contracts for Difference (CfD) projects made up 60% of the added capacity, interestingly a lower share than in 2024. Of allocation round 4 (AR4), 1.6 GWp has now been completed, with a further 500 MWp under construction. 750 MWp of AR5 has been completed, while another 850 MWp is under construction and 400 MWp of AR6 is operational.
In short, 60% of the added capacity in the last 3 years are projects that have received a CfD. It’s a shame that AR7 has been taken out (offshore results have been announced, but nothing else yet) and this round is expected to be significantly the largest ever.
Although 4.2 GWp is currently under construction, construction times are becoming longer due to the increasing project size. Of the 75 projects completed in 2025, the average size was 35 MWp. Twenty of the completed projects had a capacity of more than 50 MWp (higher local planning authority level).
Challenges for implementation in 2026
With 2026 set to be the best year ever, grid connection issues remain a concern. Some developers continue building as if nothing happened, while others wait. Even for protected projects, the continued push back on fixed date offers is causing unrest, with some projects with possible connection dates before the fourth quarter of 2026 not even starting construction.
The next concern is that, with 4.2 GWp of projects under construction, mechanical completion is the easy part. Some projects then remain in the ground for up to 18 months until the Commercial Operation Date (COD). Even if the electricity grid is reformed, this is expected to remain a problem.
Other issues of lack of progress in projects will also slow down the process with a 7 GW gap for distribution connection projects. To achieve this goal, the turnkey Gate 2 Phase 2 projects must be brought forward.
However, despite these frustrations, investor concerns and significant delays, the ground-mount market is expected to grow by up to 60%, potentially reaching the 4GWp mark for the first time. Residential roofs are expected to grow by around 20%, while commercial roofs will experience similar growth.
Strong annual growth is needed over the next four years to meet the National Energy System Operator’s (NESO) targets of 47 GW of ground-mounted solar capacity operational in Britain. Large-scale solar energy will play a major role with almost 6 GWp of approved Nationally Significant Infrastructure Projects (NSIPs) approved by the government. Little Crow Solar Farm is next to begin construction and is expected to be completed in mid to late 2027. Others have been delayed, and some hope to be connected by the end of 2029.
All the data above comes from Solar Media Market Research analysis, which can be accessedhere.
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