Commercial solar is worth it when the economics on a specific roof clear your hurdle rate after realistic assumptions — not when solar is fashionable or the roof looks big on satellite imagery. For UK commercial buildings, that usually means strong self-consumption, defensible capex, and no show-stopping engineering or grid flags at screening level.
The honest answer for many roofs is no — and that is a successful outcome if it stops wasted survey and installer spend. Feasibility exists to give you that answer in writing before you commit.
Owner-occupier vs landlord — different questions
Owner-occupiers capture savings directly when the array offsets electricity they already pay for. If your operation runs during daylight hours — manufacturing, logistics, retail, chilled storage — self-consumption can be high and payback attractive. See commercial solar payback in the UK for how the number is built.
Landlords must ask who benefits. If tenants pay the bills and the landlord funds PV, payback depends on lease clauses, rent uplifts, or export income the landlord can access. A technically strong roof can still be a poor landlord investment without a commercial structure to recover value. Portfolio landlords often find a minority of assets drive most upside — which is why portfolio solar screening matters before ordering dossiers on every address.
Self-consumption usually decides the case
UK commercial rooftop PV economics hinge on when the building draws power relative to when the roof produces. Export revenue is typically worth less per kWh than avoided import, so roofs with weak daytime load — even vast warehouses — can produce a park verdict.
Half-hourly meter data, tenant load profiles, or defensible benchmarks beat a flat “70% self-use” assumption. We explain the mechanics in self-consumption and export for commercial solar.
Treat any payback below four years with scepticism unless every assumption is disclosed. Treat any case that relies entirely on export without a contracted rate the same way.
When commercial solar is often not worth it
Several patterns recur on roofs that fail feasibility:
- Low daytime load with weak export terms — the array produces power nobody uses and export does not pay enough to compensate.
- Short remaining lease — payback extends beyond tenure without a clear mechanism to recover investment.
- Structural or wind flags at screening level — remediation cost can overturn headline economics.
- Grid constraints — G99 reinforcement, export limits, or long DNO queues that feasibility should flag before board approval.
- Imminent major roof works — installing PV twice is poor capital allocation; feasibility should align with refurbishment timing.
A park verdict on any of these grounds protects budget. It is not a comment on whether solar works in general — only whether this roof, on these terms, now is worth pursuing.
What to do before you decide
You do not need to commission surveys or accept installer visits to test the headline question. A practical sequence:
- Name the building — address, rough roof type, who pays the electricity bill.
- Screen free — free screening on one roof gives a pursue-or-park filter, panel placement, and monthly generation within three working days. No card required.
- Commission full feasibility on shortlisted sites — a fixed-fee dossier with 25-year financials, engineering flags, and sourced workings for board or asset committee use.
If an installer has already sent a proposal, read feasibility study vs installer quote before treating their PDF as an independent answer. For a step-by-step check on sales documents, see how to validate a commercial solar installer quote.
How Stage1Energy answers the question
Stage1Energy does not install solar. We produce independent feasibility — a written pursue-or-park verdict with figures you can challenge, including when the answer is do not pursue. That independence matters because free installer preliminary assessments are subsidised by expected contract value.
Read the full process in our commercial solar feasibility guide, review the example report, or start free screening on one building this week.