Commercial solar panels for UK businesses
If your business owns or leases roof space and burns most of its electricity between 8am and 5pm, rooftop solar is one of the few capital projects that pays for itself and then keeps going for another two decades. This page covers the numbers that actually decide it - roof area, generation, indicative cost and payback - without the brochure language.
The four numbers that matter
What counts as a commercial panel
There is no separate 'commercial' panel - the difference is scale and specification. Commercial roofs typically take 550–700 W bifacial or mono-PERC modules on trapezoidal or membrane fixings, wired into three-phase string inverters rather than a single small domestic unit.
How much roof you need
Allow roughly 6–8 m² of usable roof per kWp once walkways, plant, rooflights and set-backs are deducted. A 40,000 sq ft warehouse roof commonly supports 250–400 kWp, depending on purlin spacing and remaining roof life.
What it generates
UK commercial rooftops usually yield around 850–1,000 kWh per kWp per year. Orientation, pitch and shading move that figure more than panel brand does, which is why a site-specific model beats a brochure comparison.
What it costs
Installed cost is indicatively £600–£900 per kWp, falling per kWp as the array grows. Scaffolding, roof condition, DNO works and switchroom distance are the variables that move a quote most.
All figures are indicative UK ranges. Every project needs a site-specific review before any saving, price or payback is relied on.
Business solar panels at a glance
The specification ranges most UK commercial rooftop schemes sit inside. Use them to sense-check a proposal, not as a substitute for a site survey.
| Item | Typical UK range |
|---|---|
| Typical module output | 550–700 W bifacial or mono-PERC |
| Usable roof per kWp | 6–8 m² after walkways, plant and set-backs |
| Annual yield | 850–1,000 kWh per kWp per year in the UK |
| Indicative installed cost | £600–£900 per kWp, lower per kWp at scale |
| Inverter life | 10–12 years typical, extensions available |
| Panel warranty | 25–30 year performance terms are common |
| Install duration | 2–6 weeks on site for most rooftop schemes |
| Grid route | G98 for small systems, G99 above the threshold |
Solar panels for business: what decides the payback
Two identical arrays on identical roofs can pay back years apart. The difference is almost never the panel brand.
- Self-consumption. Electricity you use on site is worth full import price; exported units are worth considerably less. Weekday daytime load is the single strongest driver of return.
- Import tariff. The higher your current unit rate, the faster the array pays. Contract renewal dates matter to the model as much as the roof does.
- Tax treatment. Capital allowances and Full Expensing change the net cost materially for profit-making companies - see grants and funding.
- Roof condition and access. Scaffolding, remaining roof life and switchroom distance move quotes more than module choice does.
- Grid headroom. An export limit reduces what a large array earns, but usually not what it saves.
Find commercial solar in your region
Irradiance, DNO timescales and roof stock all vary by region. Our regional pages set out local context, and each links through to town-level detail.
- Commercial solar in the South East
- Commercial solar in the South West
- Commercial solar in the Midlands
- Commercial solar in the North West & Yorkshire
- Commercial solar in the North East
- Commercial solar in the East of England
- Commercial solar in the Wales
- Commercial solar in the Scotland
- Commercial solar in the Northern Ireland
Browse by system size
Each size page sets out typical roof area, panel count, annual generation and indicative cost, so you can sanity-check a quote before you sign anything.
- 50 kWp
50 kWp commercial solar system - cost, size and payback (UK)
£40,000–£50,000 installed · Payback 4–6 years after Full Expensing
- 100 kWp
100 kWp commercial solar system - cost, size and payback (UK)
£75,000–£90,000 installed · Payback 3.5–5 years after Full Expensing
- 150 kWp
150 kWp commercial solar system - cost, size and payback (UK)
£115,000–£135,000 installed · Payback 3.5–5 years after Full Expensing
- 250 kWp
250 kWp commercial solar system - cost, size and payback (UK)
£180,000–£220,000 installed · Payback 3.5–5 years after Full Expensing
- 500 kWp
500 kWp commercial solar system - cost, size and payback (UK)
£360,000–£420,000 installed · Payback 3.5–4.5 years after Full Expensing
- 1 MWp
1 MWp commercial solar system - cost, size and payback (UK)
£700,000–£860,000 installed · Payback 3.5–4.5 years after Full Expensing
- Battery + solar
Battery storage sizing for commercial solar (UK)
£250–£450 per kWh installed (£25k–£45k per 100 kWh) · Payback 6–9 years standalone; 5–7 years paired with new solar
- Sizing calculator
Commercial solar system size calculator (UK)
£700–£950/kWp installed · Payback 3.5–6 years typical
Where to read further
FAQ
How many commercial solar panels do I need?
Work backwards from your daytime electricity use rather than your roof. A site consuming 250,000 kWh a year with steady weekday load typically suits 150–250 kWp, which is roughly 270–450 modern panels. Our calculator sizes it in about a minute.
Which commercial solar panels are best?
Tier-1 manufacturers with UK-serviceable warranty routes and a bankable balance sheet matter more than a headline efficiency figure. Panel choice usually changes yield by a few per cent; design and self-consumption change payback by years.
Do commercial solar panels need planning permission?
Most rooftop arrays in England fall under permitted development, but listed buildings, conservation areas, some scale thresholds and ground-mounted schemes are exceptions. A site-specific check is quick and worth doing early.
How long do commercial solar panels last?
Panels normally carry 25–30 year performance warranties and keep producing beyond that at reduced output. Inverters are the shorter-lived component, typically 10–12 years with extensions available.
Can I install commercial solar panels without capital?
Yes. Asset finance, lease and PPA structures all exist for UK commercial solar. Buying outright gives the highest lifetime return; a PPA gives day-one savings with no capex.
Are solar panels for business different from domestic panels?
The modules themselves are largely the same technology. What differs is the scale, the three-phase inverter and metering arrangement, the structural and CDM work required on a commercial roof, and the grid application route. A domestic installer's process rarely transfers to a 200 kWp warehouse roof.
What size business solar panel system suits a typical warehouse?
Warehouses of 30,000–60,000 sq ft commonly land between 150 kWp and 400 kWp, limited more often by daytime consumption and grid export headroom than by roof area.
Are there grants for business solar panels in the UK?
There is no single national grant for commercial rooftop solar. The meaningful support sits in capital allowances and Full Expensing, occasional regional or sector schemes, and finance structures that remove the upfront cost. Our grants and funding page sets out what is actually claimable.