1 MWp commercial solar system — cost, size and payback (UK)
A 1 MWp system is standard for major UK distribution and fulfilment centres, energy-intensive manufacturers, and food-production giants. It's the largest system that remains under rooftop Permitted Development in England, and the point at which corporate PPAs and flexibility markets deliver material additional value.
1 MWp at a glance
Best fit business types
- Big-box distribution and fulfilment (150k+ sq ft)
- Automotive and heavy manufacturing
- Large food-production plants
- Data centres and hyperscalers
- Portfolio landlords deploying across multiple sites
Design and spec notes
- Multi-central-inverter or string architecture on high-density roofs.
- DNO G99 approval, often with export limitation or new HV connection.
- Corporate PPA and sleeved-PPA structures widely used.
- Battery pairing (1–2 MWh) unlocks Balancing Mechanism and DFS income.
Related reading
FAQ — 1 MWp systems
Is 1 MWp the largest rooftop system allowed?
1 MWp is the practical cap for Permitted Development in England on most non-domestic rooftops. Larger arrays are possible but usually need a planning application.
What's the lead time for a 1 MWp system?
Typically 6–9 months from signed order to first generation, driven by DNO approval and equipment lead times.
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