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What’s the maximum number of solar panels you can have in the UK?

josh jackman
Written By
Christopher McFadden
Reviewed By
Updated on 23 June 2025
  • You can install as many solar panels as you want – there’s no legal limit in the UK
  • But if your system exceeds 3.68 kWp, your installer must get approval from your local electricity network (DNO)
  • Bigger isn’t always better – oversized systems often cost more than they save
Solar panel technician in orange with drill installing solar panels on a roof
Credit: Torino

If you’re wondering ‘how much do solar panels cost?’ then good news, the cost of solar panels continues to tumble – falling by 4.5% from March 2024-2025 – and they can cut your energy bills by 70%, so it’s understandable to get as many as possible, especially with the government grants that help with the upfront cost. 

In this guide, we’ll look at the details of many solar panels you can have installed.

If you want to go solar at any point, you can compare solar panel prices with our help. Just provide a few quick details, and our expert installers will be in touch with free quotes for you to compare.

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In short, there isn’t one, you can have as many solar panels on your roof as you like.  Nothing legally prevents you from having as many solar panels as you want or can afford.

There is, however, a physical limit based on the size of the space you have on your roof or land to put them. However, it is possible to have too many solar panels in terms of cost-effectiveness. If you produce more solar energy than you need, you’ll end up overpaying for the system.

But as long as they’re safely installed, properly connected to your electricity supply, entirely situated on your property, and follow all relevant planning permission rules (though solar panels are usually considered permitted development), nothing is stopping you from having as many solar panels as you want.

Once again, in short, there is no maximum amount of solar energy production limit in the UK (beyond physical limitations, of course). If you are interested in finding out how much power your panels can produce, check out our solar panel output calculator. 

That said, your solar panel installer must inform your Distribution Network Operator (DNO) – the company controlling the hardware that supplies your area with electricity – before installing a system with a peak power capacity above 3.68 kWp per phase.

That means if you have a single-phase setup, as the great majority of UK homes do, you’ll need prior approval for any installation above 3.68 kWp.

A household with three-phase electricity will be able to install 11.04 kWp – 3.68 kWp for each of its phases, without asking for permission in advance of the installation.

Upgrading your electricity supply from single-phase to three-phase typically costs between £3,500 and £8,000.

If your installer does have to ask for approval before the job, that’s no reason to worry. Solar panel systems under 5 kWp are usually approved without any issues. Installations above 5 kW typically require additional checks, but still almost always receive a stamp of approval, albeit with a slight delay.

Again, while there is no physical or legal limit on the amount, you can end up overpaying if you produce more energy than you need.  

Totals vary, but the average roof on a three-bedroom house in the UK can hold between 10 and 20 solar panels.

By way of example, consider a home with a roof area of 70 m², which is enough space to fit five rows of four solar panels. Considering that solar panels are usually about 2 m², you should, in theory, be able to accommodate more than 20 on such a roof.

However, your installer is legally required to leave at least 20 cm of space between your panels and the edge of the roof on every side.

They’ll also usually ensure there’s about 15 cm between each row of solar panels, to give the frames space to contract and expand as temperatures change throughout the year.

Thankfully, space is usually the only issue, as most UK roofs can typically support the weight of a solar panel installation.

Our roofs can usually support at least 108 kg per square metre, which is 12.5 times as much as the average solar panel needs. However, older roofs, especially those originally designed to hold quarry slate, may have significantly reduced weight-bearing capacities. 

Your solar panel installer will advise you in any case. 

The average three-bedroom household should have 10 solar panels.

We’re assuming this home consumes 2,700 kWh of electricity per year – the national average – and will use 50% of its solar energy, which again is typical.

The average one-bedroom house should get six solar panels, while a bigger household with four or five bedrooms will usually need 14 panels.

Check out our guide to see how many solar panels you need for your home.

Aside from the upfront cost, there are no downsides to large solar panel systems, as long as it makes sense for your household.

If you use a lot of electricity – for instance, more than 4,000 kWh per year – you can save several hundred pounds on your energy bills per year with solar panels.

But if you buy a solar panel system that produces significantly more electricity than you can use, you won’t break even as quickly.

You’ll still make money from exporting your excess energy to the grid, through the Smart Export Guarantee, but you’ll almost certainly receive less than you pay the grid for electricity.

This means that every extra solar panel you install above the optimal number for your home will add 0.4 years to your break-even point, on average.

To work out what size solar panel system you need, just use our solar panel output calculator.

  • There’s no legal limit to how many solar panels you can install in the UK
  • Most homes can support 10 to 20 panels, depending on roof space and layout
  • Systems above 3.68 kWp usually need prior approval from your DNO
  • Oversized solar systems take longer to break even and offer lower returns
  • Three-phase power lets you install larger systems without extra approvals
  • Use our calculator to find your ideal system size and get free quotes from trusted installers

Written By

josh jackman

Josh has written about and reported on eco-friendly home improvements and climate change for the past four years.

His data-driven work has featured on the front page of the Financial Times and in publications including The Independent, Telegraph, Times, Sun, Daily Express, and Fox News, earned him the position of resident expert in BT’s smart home tech initiative, and been referenced in official United Nations and World Health Organisation documents.

He’s also been interviewed on BBC One’s Rip-Off Britain, BBC Radio 4, and BBC Radio 5 Live as an expert on everything from renewable energy to government policy and space travel’s carbon footprint, and regularly attends Grand Designs Live as a Green Living Expert, giving bespoke advice to members of the public about heat pumps and solar panels.

Josh has also used the journalistic skills he developed at The Jewish Chronicle and PinkNews to investigate and analyse every green government grant in existence, and examine the impact on the climate of cryptocurrency, Glastonbury Festival, and the World Cup.

You can get in touch with Josh via email.

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Reviewed By

Christopher McFadden

Christopher is an Environment, Health & Safety (EHS) specialist with extensive experience advising consumer and trade clients on energy efficiency and sustainability.

With a Master’s in Earth Sciences from Cardiff University, Christopher has attained professional energy and sustainability auditing qualifications and various postgraduate certificates and diplomas. He is a qualified and accredited Level 3 and Level 4 non-domestic and domestic energy assessor, a Green Deal assessor, and a Practitioner member of the Institute of Environmental Management and Assessment (IEMA). He also recently qualified as a level 5 Retrofit coordinator.

In addition to his day job, Christopher has also honed his skills as a STEM writer for several well-known online publishers, sharing his knowledge and passion for science, engineering, and dinosaurs with millions of readers around the world.

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