What's the Maximum Number of Solar Panels Allowed in the UK?

With solar panels, it’s usually a case of “the more, the merrier” since there is no maximum amount as long as you have permission. However, physical limitations, certain legal regulations, and best practices can limit the maximum number of solar panels you can install. Let’s go over what you need to consider before deciding how many solar panels you need.

That said, we can only advise you with estimates. The best way to gauge how many panels you can install and get accurate solar panel cost figures is to contact an installer. A reliable installer can be hard to find, requiring hours of research and calling up companies. Our service simplifies the process down to a 30-second form and provides you with up to 4 free, non-binding quotes.

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There is no maximum number of solar panels you are allowed to install. However, installations above 3.68kW will require permission from the local Distribution Network Operator (DNO). For larger systems, you need a G99 application. Aside from that, the max number of solar panels allowed in the UK is limited primarily by the space you have or regional specifics.

For smaller systems, you won’t need planning permission to install solar panels, unless they are on a dwelling and or are visible from a road. There are certain types of properties that are more likely to require planning permission. These include:

If you’re wondering, “how many solar panels can I have on my roof?”, that’s a different question. Solar panel sizes are generally measured in kilowatts (kW), with each kW unit being roughly 2m2. Here is the average size of solar panel systems in the UK.

Generally, a 3 bedroom home will have 70m2 to 75m2 but not all of it will be usable space. Roof sizes can vary and many roofs can have physical disruptions that make it difficult to gauge how many panels it would need.

Moreover, the best roof angle and direction for solar panels is a southward-facing roof with a 30° to 40° incline, so there is a chance that only part of your roof will be worth outfitting with solar panels. This can leave you with limited space since north-facing directions may not provide a significant return on investment, although there’s no rule stopping you from installing it.

In total, the average home has enough space for 20 solar panels. Since solar panels are about 2m2, quite a lot of them can be installed on a roof. Assuming you have 20m2 of viable roof space, you could fit a 4kW system on the average 3-bedroom home.

There is no maximum legal limit on how much energy you can produce with solar panels. As long as you have a big enough inverter, your solar panels should be able to capture as much sunlight as you want. As long as your system doesn’t exceed 5MW (megawatts), you can even continue to earn money by exporting energy to the grid.

Of course, every solar panel has physical limitations on the amount of energy it can produce, indicated by the rated capacity, which is about 1kW per metre square. In reality, many factors prevent solar panels from achieving this precisely. Over the course of their 25-year lifespan, each kW worth of solar panels will generate roughly 20,000kWh of electricity in the UK.

Your phase connection may also limit the size of the system you can opt for. Most networks allow system sizes based on their phase connection. The maximum solar energy on a single phase in the UK (which applies to the majority of homes) is up to the electricity output limit 3.68kW (per phase). Other larger homes and businesses run on a 3-phase connection with up to 11kW. Any larger wattage will require DNO permission.

It’s also worth noting that network size limits may not necessarily be set in stone. You could still get a larger solar panel system with a single-phase inverter. However, this may require more bureaucracy and lead to longer wait times and additional charges.

Yes, you can install multiple solar panel systems as long as you have permission from the DNO and the second system doesn’t interfere with metre readings and SEG export amounts. This can have some benefits, as your home setup may not be suitable for one large solar panel system, requiring you to divide it.

Running two systems can be tricky since it may require twice the equipment in certain respects. You’ll have to deal with 2 solar panels, multiple sets of monitoring apps, and multiple warranties. Another thing worth considering is that you will have to pay for two different installations and, if applicable, separate removal fees for your panels.

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The number of solar panels you should have depends on what you want to use them for. If you’re looking to cover electricity needs for an average-sized household, you won’t need more than 10 panels. However, if you are aiming to earn money by exporting energy back to the grid, you will want to exceed your energy consumption.

If you’ve ever wondered “How many solar panels do I need to cover my home’s energy needs?”, you will need to determine your annual energy consumption first. Here’s a handy image with multiple house sizes.

Out of the most common sizes, 4kW solar panel systems with 8 to 10 panels can cover most energy needs for the average home. Since most homes require 2,700kWh per month in energy generation, a bigger system may be unnecessary. A 6kW solar system can be sufficient for most larger homes.

Commercial solar panels can be even larger, starting at 10kW solar system setups and going up to 100kW systems. These will be more appropriate for businesses and large buildings with higher energy demand.

If you want to learn more about what size solar panels are most suitable for your home, you should consult a professional installer. There are many factors to consider so it can be difficult to know without a proper assessment.

However, you should be sure that you’re hiring a reliable installer, which can take up hours of your time. If that sounds tedious and time consuming, you can instead try our service. We have an extensive network of solar panel installers that we’ve vetted ourselves.

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