In 2026, the UK solar market will grow by 5-5.5GW, according to forecasting by Solar Media Market Research analyst Josh Cornes.
February 3, 2026
In this contributed article, Josh Cornes, solar analyst at Solar Media Market Research, outlines his forecast of how the UK's solar market will shape up in 2026, covering capacity added and some of the challenges that developers may come up against.
The UK solar market is forecast to grow by 50% year on year (YoY) for the second year in a row, expected to add 5-5.5GWp-dc of capacity in 2026, comfortably the best year on record.
The market grew 50% YoY in 2025 (as predicted at the start of the year), taking the total capacity past 23GWp with 3.5GWp added. Growth in 2025 was largely driven by ground-mount, nearly double as much installed in that segment as was completed in 2024.
Residential rooftop also had a good year, with over 650MW added, helped by the number of initiatives being introduced and proposed by the Government over the last 12 months.
In 2024, ground mount made up 60% of the total capacity, in 2025 this rose to 70%, furthering the trend of ground mount taking increasing importance in the market and is forecast to continue to grow YoY. Residential rooftop accounted for 18%, with commercial rooftops making up the rest. The residential rooftop market had its best year on record, with a 25% YoY increase.
2025 finishes as the most active year since UK solar market began, Phase 1 shortfall remains
Figure 1 shows the significant amount of solar added in 2025, as well as the considerable uptick in ground-mounted solar. Rooftop has remained steady over the last five years, with 2026 set to be slightly unpredictable due to the aforementioned number of initiatives the Labour Government continues to bring in.
Figure 1: Cumulative solar capacity and added capacity by year. The lines highlight the growing importance of ground mount, as it continues to make up a larger portion of the added capacity YoY.
Excluding Cleve Hill Solar Farm, half of the remaining capacity came from just four developers, with one completing 350MWp.
Projects with Contracts for Difference (CfD) made up 60% of the added capacity, interestingly a lower proportion than in 2024. From Allocation Round 4 (AR4), 1.6GWp is now completed, with another 500MWp under construction. 750MWp of AR5 is completed, with a further 850MWp under construction and 400MWp of AR6 is operational.
In short, 60% of the capacity added in the last 3 years are projects that have received a CfD. It’s a shame that AR7 has been pushed out (results for offshore have been announced but nothing further yet) with this round expected to be the largest on record, significantly.
Although there’s 4.2GWp under construction currently, build out times continue to get longer due to increasing project size. Across the 75 projects being completed in 2025, the average size was 35MWp. 20 of the projects completed were greater than 50MWp (higher end Local Planning Authority level).
Transmission chaos: developers need answers as grid connection offers pushed back
With 2026 set to be the best year on record, grid connection issues remain a worry. Some developers continue to begin construction as if nothing is happening, whilst others wait. Even with protected projects, the continuous push back of firm date offers going out is causing unease, with some projects that potentially have Q4 2026 connection dates not even starting construction.
The next worry 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 with grid reform, this is expected to be an issue.
Other issues of lack of advancements in projects are also going to slow the process with a headroom of 7GW for distribution connection projects, to hit this target the ready to build Gate 2 Phase 2 projects must be advanced.
However, despite these frustrations, investor worries and firm date delays, the ground-mount market is expected to grow by up to 60%, potentially touching 4GWp for the first time. Residential rooftop is expected to grow by around 20% and commercial rooftop is set to see a similar growth.
Triple Point acquires 28MW Essex solar PV project
Over the next four years, strong growth is required YoY to hit targets set by the National Energy System Operator (NESO) of 47GW of ground-mount solar capacity operational in the UK. Large scale solar is set to play a big role with nearly 6GWp of approved Nationally Significant Infrastructure Projects (NSIPs) that have been approved by the government, Little Crow Solar Farm is the next to begin construction, estimated to be completed by mid to late 2027. Others have been delayed, with a number hoping to be connected by the end of 2029.
All the data above is taken from Solar Media Market Research’s analysis, which can be accessed here.
To book a demo and access the data, please email [email protected].
Read more about:
Josh Cornes
Market analyst, Solar Media, Solar Media Market Research
Josh Cornes joined Solar Media in May 2022. He's a Market Research Analyst who specialises in the UK Solar and Wind sectors, tracking all projects within development to create informative reports and write data driven articles on UK trends and market sizing.
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