The UK solar market smashed records in 2025. MCS-certified installations hit 257,397 — a 32% surge over 2024 and the highest annual total ever recorded. Total deployed capacity reached approximately 21.6 GW by year-end (DESNZ provisional), with Solar Media estimating as much as 23.8 GW when accounting for pipeline projects. Solar generated an estimated 18,314 GWh, up 30% from 14,067 GWh in 2024, contributing roughly 6.4% of UK electricity.
And 2026 is forecast to grow another 50% year-on-year. Here is what is driving the acceleration and what it means for installers, investors, and policymakers.
Installation Volumes: Breaking Down the Record
Q1 2025 delivered 57,000 installations — the strongest first quarter since 2012. March 2025 alone saw approximately 24,000 installations. The full-year total of 257,397 beat the previous annual record of 203,125 set in 2011 during the original Feed-in Tariff boom. Cumulative MCS-certified installations now total 1.85 million.
A notable structural shift: new-build installations accounted for 35% of all 2025 installations, up from 32% when MCS began tracking in October 2023. The impending Future Homes Standard — requiring new English homes to produce significantly fewer carbon emissions — is driving developers to include solar as standard rather than optional.
The commercial sector is growing faster than residential. Ground-mounted utility-scale projects commanded 70% of capacity added in 2025, with residential rooftop at 18% and commercial rooftop at approximately 12% by capacity. However, by installation count, residential still dominates at 73-86% of total.
Market Size and Installer Landscape
The solar panel installation industry was valued at £2.1 billion in 2024-25 (IBISWorld), having grown at a compound annual rate of 31.1% over five years. IMARC Group's broader valuation covering the full solar energy value chain puts the market at approximately £8 billion, projected to reach USD 26.9 billion by 2034.
The UK now has over 5,250 MCS-certified contractors — the highest since MCS began in 2008. Of these, over 4,000 hold solar PV certification, with 718 new solar PV contractors certified in 2024 alone. This expansion is both an opportunity and a challenge: more installers means more competition for the same leads, driving up marketing costs and putting pressure on margins.
Battery Attachment Rate: Higher Than Anyone Thought
The official MCS-recorded battery attachment rate sits at approximately 20%, but this is widely considered a significant undercount since battery certification is not mandatory. SunWiz analysis suggests the true rate approaches universality in many regions. MCS-certified battery installations surged from 4,965 in 2023 to approximately 59,000 in the first nine months of 2025 — a 122% year-on-year increase.
This has profound implications for the value proposition of solar. With battery storage, self-consumption jumps from 30-50% to 60-80%, fundamentally changing the ROI calculation. Battery costs have fallen 93% over the past decade, with the marginal cost of adding a battery to a new installation now just £1,000-£1,500.
Policy: 0% VAT Sunset and the Warm Homes Pivot
The 0% VAT rate on residential solar expires 31 March 2027, reverting to 5%. No extension has been announced. This creates urgency: on a typical £7,279 system, the 0% rate saves approximately £1,456 compared to standard VAT. Expect a surge of pre-deadline installations through early 2027.
ECO4 was confirmed to end without extension, with the government transitioning to the Warm Homes Plan. The Boiler Upgrade Scheme has been extended to 2030 with a £295 million annual budget. ESOS Phase 4 qualification date of 31 December 2026 is pushing large businesses toward solar investment.
The government's Clean Power 2030 Action Plan targets 45-47 GW of solar capacity by 2030. With approximately 22 GW deployed as of early 2026, this requires adding roughly 5.5-6 GW per year — more than double the 2.6 GW added in 2025. The UK's 2025 solar output was boosted by the sunniest year on record (1,622+ hours, Met Office), demonstrating the generation potential of the growing fleet.
What This Means for Installers
The opportunity is clear: record demand, government targets requiring a doubling of installation rates, and a 0% VAT deadline creating a ticking clock. But competition is intensifying with 5,250+ certified contractors. The installers winning market share are those with strong local SEO presence, sector specialisation (schools, hospitality, industrial), and efficient lead-to-close processes.
For a detailed analysis of marketing costs and strategies, see our solar installer marketing guide. For commercial sector trends, see our commercial solar analysis.