Generating 1 megawatt (1MW) of solar power typically takes between 2,000 and 2,900 panels, depending on the wattage you’re working with – modern high-output panels around 450-500W need fewer than older or budget 350W panels. A 1MW installation sits firmly in commercial or utility territory rather than domestic, and it comes with a land, cost and grid-connection conversation that’s very different to sizing a house roof.
How Many Panels You Need by Wattage
| Panel wattage | Panels needed for 1MW |
|---|---|
| 350W | ~2,857 panels |
| 400W | ~2,500 panels |
| 450W | ~2,222 panels |
| 500W | ~2,000 panels |
These figures are for the DC nameplate capacity of the array (1MWp, “peak”), which isn’t the same as 1MW of continuous output – like any solar array, actual output varies through the day and year, and a 1MWp installation typically generates over 1,000,000 kWh annually in a reasonably sunny UK location.
Land Area Needed for a 1MW Solar Installation
How much space you need depends heavily on whether it’s roof-mounted or ground-mounted. Rooftop systems need roughly 4,000-5,000m² (around 1-1.25 acres) of usable, unshaded roof area, which is why 1MW rooftop arrays are usually only feasible on large warehouses, distribution centres or big agricultural buildings. Ground-mounted arrays need considerably more – typically 6,000-9,000m² (1.5-2.2 acres) – because panels need row spacing to avoid shading each other as the sun moves, plus access paths for maintenance and, often, a security perimeter.
How Many UK Homes Can a 1MW Solar Installation Power?
With average UK household electricity consumption sitting around 2,700-3,000 kWh a year, and a well-sited 1MW installation generating over 1,000,000 kWh annually, the maths works out to roughly 330-370 average homes’ worth of annual electricity – though this is a useful comparison for scale rather than a literal claim, since a solar farm generates during daylight and homes consume around the clock, meaning the electricity is fed to the grid generally rather than following a direct one-to-one household connection.
Is a 1MW System More Likely to Be Rooftop or Ground-Mounted?
In practice, 1MW ground-mounted solar farms are far more common than 1MW rooftop installations, simply because very few individual buildings have 4,000m²+ of usable, unshaded, structurally suitable roof space. Large distribution warehouses, big agricultural sheds (see our guide on solar panels for farms) and some industrial sites are among the few building types that can approach this scale on the roof alone; most 1MW-class projects are dedicated ground-mounted solar farms instead.
Planning Permission for a 1MW Installation
At 1MW, you’re well beyond the domestic permitted development thresholds that cover most house roof installations. Ground-mounted arrays of this size almost always require full planning permission from the local authority, and larger utility-scale projects (roughly above 50MW in England, with different thresholds in Scotland and Wales) can be classed as Nationally Significant Infrastructure Projects requiring a different consent route entirely. At 1MW specifically, you’re typically dealing with standard local planning permission rather than the NSIP process, but expect requirements around landscaping, ecological surveys, and grid connection agreements as standard conditions.
Grid Connection Considerations at 1MW
A 1MW export capacity typically requires a higher-voltage grid connection than a standard domestic or small commercial installation, and depending on the strength of the local network, the district network operator (DNO) may need to carry out reinforcement work before granting a connection offer – this can be one of the longest lead-time items in a 1MW project, sometimes taking longer than the physical construction itself. Getting an early, informal capacity check from the DNO before committing significant design costs is standard practice at this scale.
Rough Cost Expectations for a 1MW Installation
Costs vary considerably with site conditions, but ground-mounted commercial solar at this scale often falls somewhere in the region of £500,000-£800,000 all-in for a 1MW installation, before accounting for available capital allowances (see our guide on questions to ask an installer, several of which apply at commercial scale too) which can substantially reduce the effective net cost for a UK business or landowner.
Frequently Asked Questions About Generating 1 Megawatt of Solar Power
How many solar panels does it actually take to generate 1MW?
Typically between 2,000 panels (using 500W panels) and 2,900 panels (using 350W panels). The exact number depends entirely on the wattage of the specific panel model chosen, with higher-wattage panels needing fewer units to reach the same total capacity.
What is the difference between 1MW and 1MWp for solar?
1MWp (“megawatt peak”) refers to the array’s total rated DC capacity under standard test conditions, while 1MW of actual output only happens briefly under near-ideal sunlight. In everyday use, a 1MWp system’s real-world output varies throughout the day and year, similarly to how a domestic system’s kWp rating differs from its actual generation.
How much does a 1MW solar farm cost to build in the UK?
Broadly in the region of £500,000-£800,000, though this varies with site preparation needs, grid connection costs, and panel/inverter specification. Costs have fallen considerably over the past decade as panel prices have dropped, though grid connection and land costs have become a larger relative share of total project cost.
Do I need planning permission for a 1MW solar installation?
Almost certainly yes for a ground-mounted array at this scale – it falls well outside permitted development rights, which are designed for small domestic installations. Full planning permission from the local authority is the standard route for 1MW projects, alongside ecological and landscaping assessments typically required as part of the application.
