Installer guide · 20 min read

The UK Commercial Solar Market in 2026: Size, Growth and Trends

Short answer: the UK had a provisional 23.2 GW of solar across 2,130,896 installations at the end of August 2026, up 9.0% in a year, according to the government's own monthly statistics. The 10 kW to under 5 MW bands, where most business systems sit, account for 5.9 GW of that. Every figure below comes from DESNZ, Ofgem, MCS or legislation.gov.uk, with the period it covers, so you can quote it with confidence.

Data checked 7 October 2026 (trends section updated 22 October 2026; Solar Roadmap and Clean Power 2030 section added 23 October 2026; key figures re-checked against DESNZ ET 6.3 on 24 October 2026). Latest DESNZ release: August 2026 data, published 29 September 2026. For the full year-by-year tables since 2010, month-by-month figures for the commercial bands and solar's share of UK electricity, see our UK commercial solar statistics data page.

Key numbers

DESNZ adds that during August 2026 alone there were 24,154 new installations totalling 124 MW, and that the median over the past 12 months is over 24,000 installations a month, against around 3,000 a month between 2016 and 2021. Over 2025 as a whole, 269,500 installations came online, the most of any calendar year, and the 2.7 GW added was the highest annual figure since 2015.

UK solar by size band

This is DESNZ Table 1 for the whole UK at the end of August 2026. The main table in this release uses the capacity bands DESNZ introduced in December 2025 to line up with government scheme eligibility, so a 5 MW site sits in the 5 to under 25 MW band rather than the band below. The "typical sites" column is our reading of what each band usually contains, not a DESNZ classification.

Two things stand out. Systems under 50 kW are 99.6% of all installations (our calculation) but only 38% of capacity. And the 50 kW to under 5 MW band, which covers most commercial and industrial rooftops, is under 0.5% of installations but 17% of capacity, at an average of around 450 kW per site. Fewer jobs, much bigger jobs: that is the commercial market in one line.

What the size bands mean for a commercial installer

Most commercial rooftops land somewhere between 10 kW and 5 MW. A small workshop or surgery sits in the 10 to 50 kW band; a warehouse, factory, cold store or large farm building is usually in the 50 kW to 5 MW band. Together those two bands hold 5.9 GW on 101,496 installations, about a quarter of UK capacity.

Read them with two caveats from DESNZ itself. First, the statistics "do not currently include all unsubsidised solar installations below 150 kW capacity" that are missing from its data sources, which are mainly MCS, the Renewable Energy Planning Database (sites over 150 kW), the old subsidy registers and a survey of large operators. A commercial roof of 60 to 150 kW installed without MCS registration and outside the planning database may not be counted. Second, the domestic split is by property type: 7.1 GW and 1,761,110 installations are recorded as being on homes, which leaves around 370,000 installations and 16.2 GW (our calculation) that are not recorded as domestic, including every solar farm.

Ofgem's Smart Export Guarantee data gives a second view of the smaller end. SEG tariffs are open to installations up to 5 MW, and at 31 March 2025 the 270,331 solar PV registrations broke down like this:

Only 745 SEG registrations are above 50 kW. SEG only counts sites that signed up to an export tariff, so this is not a count of commercial systems, and its bands are not the same as DESNZ's.

UK solar market trends: how each band has grown

These three columns all come from the September 2026 release, so they use the same band definitions and the same revisions and can be compared directly. Figures are UK cumulative capacity in MW at the end of August each year.

The 10 to under 50 kW band grew 19.4% in capacity and 26.0% in number (73,449 to 92,553 installations) in the year to August 2026. The 50 kW to under 5 MW band grew far more slowly on paper, by 57 MW and 421 installations. Given the coverage gap below 150 kW and the fact that DESNZ often hears about new sites months after they are built, treat that band's recent growth as a floor rather than the full picture. The largest farms (25 MW and over) added 503 MW.

Four longer-run trends in the UK photovoltaic market come out of the same DESNZ data. Small commercial is having its best years: the 10 to under 50 kW band added 15,070 installations in 2025, the most of any year since 2010 (our calculation). The 50 kW to 5 MW band adds around 80 MW a year on paper, against more than 1 GW a year in 2015 and 2016. Domestic solar is growing its share again, from about 24% of capacity for most of the years since 2017 to 30% now, according to DESNZ. And solar's share of the electricity the UK generates rose from 2.2% in 2015 to 6.9% in 2025, reaching 12.3% in April to June 2026 (DESNZ ET 6.1). The year-by-year tables behind each of these are on our UK commercial solar statistics page.

Solar by region

DESNZ added a regional table (Table 4) in its August 2026 publication. Capacity here includes solar farms, which is why rural regions lead, so use it as a guide to where solar is established rather than where the next commercial roof is.

A further 84 MW and 16,082 installations are unallocated to a region (including the pre-2009 estimate). If you are planning where to focus a sales team, pair this with your own data on travel time and survey capacity; our commercial solar lead calculator helps you turn install targets into the number of site meetings you need.

Targets and policy behind commercial demand

The 2030 ambition. The Clean Power 2030 Action Plan (December 2024) sets expectations of 45 to 47 GW of solar by 2030. The Solar Roadmap (June 2025) explains that this is a Great Britain ambition for all solar, ground mount and rooftop, with grid capacity available for up to an additional 10 GW if the system needs it. In the Roadmap's illustrative "current policy" scenario, around 15 to 20% of 2030 capacity could be commercial rooftop and ground mount, and removing rooftop barriers could take commercial rooftop and ground mount to more than 10 GW by 2030. These are scenarios, not forecasts.

Planning in England. SI 2023/1279 came into force on 21 December 2023. It amended Class J of Part 14 of the permitted development rules (solar on non-domestic premises) to remove the 1 megawatt capacity threshold, and to allow solar on a roof slope fronting a highway on article 2(3) land. The Roadmap notes that the 1 MW cap had been one of the main challenges for commercial rooftop solar. Other conditions still apply, so check each site. The Roadmap also refers to a permitted development right for solar canopies in non-domestic off-street car parks in England.

Business electricity prices. The demand driver most installers lead with is the bill. DESNZ's non-domestic price survey shows what businesses actually pay, by annual consumption band:

On the all-consumer average, businesses paid about 1.9 times their 2019 unit price in the second quarter of 2026 (our calculation). Prices for each band are averages across contracts, so a given business may pay more or less.

UK Solar Roadmap and Clean Power 2030: what they mean for commercial installers

Two government documents set the direction for solar to 2030. The Clean Power 2030 Action Plan (DESNZ, December 2024) sets a Great Britain ambition of 45 to 47 GW of solar by 2030, against 16.6 GW installed in the second quarter of 2024. The Solar Roadmap (DESNZ, 30 June 2025) gives the Solar Taskforce's final conclusions and the actions government and industry will take to get there, with a new Solar Council, chaired jointly by government and industry, to track progress. The points below are what the documents themselves say.

The scenarios. The Roadmap models three illustrative pathways. With no significant change in policy ("business as usual"), capacity reaches about 30 GW in 2030. At the top of the "current policy" range it reaches 45 to 47 GW in 2030 and 75 GW by 2035. With "further rooftop barriers removed", including measures aimed at commercial rooftop, it exceeds 50 GW in 2030 and reaches around 85 GW by 2035. The Roadmap stresses that these are not forecasts, and that they do not reflect the full technical potential of commercial rooftop.

Smaller projects and the grid. Projects below the threshold for a transmission impact assessment (TIA) do not need to align with the Clean Power capacity ranges for connections reform, so small-scale solar is in effect exempt from that part. Ofgem approved raising the TIA threshold in England and Wales from 1 MW to 5 MW in May 2025. NESO-led work with the distribution network operators suggested a further 9 to 10 GW of smaller rooftop projects could deploy before 2030, subject to the pipeline; the Roadmap calls the resulting 57 GW closer to a theoretical maximum than a forecast.

The commercial rooftop actions. The Roadmap numbers its commitments. The ones aimed at business and public buildings are:

• Action 9: two options for the Future Buildings Standard, both leading to solar on new non-domestic buildings, with a government response promised for autumn 2025.
• Action 10: the UK Warehousing Association and the logistics, real estate and solar industries to streamline rooftop solar on leased commercial buildings and write guidance on landlord and tenant agreements.
• Action 11: the National Wealth Fund to explore ways to finance solar projects or portfolios, including PPAs with sub-investment grade buyers.
• Action 12: a Department for Business and Trade steering group to consider how government could promote corporate PPAs.
• Action 13: solar on around 200 schools and 200 hospitals, match funded by Great British Energy and government.
• Actions 21, 23 and 24: distribution network operators to consider how to make solar on large new non-domestic buildings easier and a common approach to witness testing; independent network operators, which run many business park networks, to review their solar connection processes; and an Ofgem review of their regulation.
• Action 32: Solar Energy UK to develop an exemplary fair contracts and fair payment document.
• Action 56: a UK Warehousing Association toolkit for warehouse owners and occupiers on design, permissions, legal points and grid connection.

What to do with it. Lead with the policy only where it helps the customer decide: landlord consent on leased sites, grid limits on larger roofs and finance for buyers without a strong credit rating are the barriers the Roadmap itself names. Our guides cover the routes it points to: commercial solar PPAs, offering finance on commercial solar and public sector solar funding.

Where the commercial opportunity is

Official sources name a handful of sectors. Treat the estimates below as the Roadmap reports them: some come from industry bodies rather than government.

• Warehouses and logistics. The Roadmap defines commercial rooftops as municipal buildings, industrial and manufacturing buildings, offices and warehouses. It cites UK Warehousing Association estimates that the largest 20% of warehouses offer 75 million square metres of roof, enough for around 15 GW of rooftop solar.
• Leased commercial buildings. The Roadmap names landlord and tenant lease structures as a barrier and commits industry to guidance and a standard form of agreement for retrofitting solar on leased industrial and commercial buildings. Landlord consent is the first thing to check on any tenanted site.
• Public sector. Great British Energy's first major project funds rooftop solar on around 200 schools and up to 200 hospitals in England. Public bodies usually buy through tenders and frameworks; see our guide to commercial solar tenders and frameworks.
• Car parks. The Clean Power 2030 Action Plan committed to a call for evidence on solar canopies over outdoor car parks, and the Roadmap repeats it.
• Finance-constrained businesses. The Roadmap notes that behind-the-meter solar can be hard to finance for businesses without a strong credit rating, so commercial rooftop has tended to be restricted to major corporates, "leaving a large part of the market untapped".

What it means for winning work

The numbers say the same thing commercial installers feel on the ground: business jobs are few, big and slow to land. Around 9,000 UK installations sit in the 50 kW to under 5 MW band after more than a decade of deployment, so every qualified conversation with a building owner who pays a large electricity bill is worth a lot of pipeline.

TNW Marketing books pre-qualified, exclusive commercial solar site meetings with the decision-maker for UK installers. Before a meeting is booked, the business is checked for property ownership or landlord consent, energy spend, roof or land suitability and buying intent, using outbound calling, email, LinkedIn and paid ads to find them. You pay per qualified, attended appointment, with no retainer and no minimum spend, and bookings that cancel, don't show or don't match the agreed brief are replaced or refunded rather than charged. The show rate is 60%+. See how that works in detail on our pay per appointment commercial solar leads page, or how appointment setting for solar installers differs from general B2B calling.

If you are weighing up suppliers, our comparison of commercial solar lead generation companies and the guide to pay-per-lead vs retainer pricing set out the trade-offs. For budgeting, read what commercial solar leads cost in the UK and the wider commercial solar lead generation guide. Our checklist on how to qualify commercial solar leads covers the ownership, lease and energy-use questions the statistics above point to. For proof from installers we work with, see client results, the case studies and video reviews.

How often the statistics update, and where to get them

• DESNZ solar deployment (ET 6.3): monthly, a month in arrears, now published on the Energy Trends: UK renewables page. August 2026 data came out on 29 September 2026; September 2026 data is due on 29 October 2026. The latest month is provisional and usually revised up.
• Non-domestic energy prices (QEP 3.4.1 and 3.4.2): quarterly; the next update is due 17 December 2026.
• MCS Data Dashboard: updated every 24 hours, covering MCS-certified installations up to 50 kWe. Useful for the small commercial end; not a full count, as MCS certification is not mandatory.
• Ofgem SEG annual report: yearly, for the SEG year ending 31 March. The April 2024 to March 2025 report is the latest at the time of writing.

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