How are solar panels installed?

Installation
Last updated on 22 July 202414 min read

Here's how a solar panel installation works from start to finish, and what you should do before and after the installation.

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Written byJosh Jackman
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Solar panel installation: at a glance

🏠 The first step of a solar panel installation is a survey of your property

After you’ve initially shown interest in a solar installer’s services, the company should arrange for an expert to carry out a remote assessment of your roof.

This specialist will evaluate the roof’s condition, orientation, and incline, as well as how shaded it is and how much available space it has.

The great majority of UK roofs can comfortably hold a solar panel system’s weight, which is usually around 20kg per square metre.

🛠️ Scaffolding will usually go up four or five days beforehand

Scaffolding will be erected around your home four or five days before the installation.

It’ll then usually be taken down around five days after it’s over – unless you have a particularly conscientious installer.

In this case, they’ll leave the scaffolding up for one to two weeks, because if anything goes wrong, you won’t have to pay for scaffolding to be constructed all over again.

🗓️ Most solar panel installations take between one and three days

Your installation will be over before you know it, with most jobs taking between one and three days.

How much time it takes to install your system will largely depend on its size and complexity.

Before the team arrives, make sure they can access your loft, consumer unit (also known as a fuse box), and fuse, as well as any routes between these locations.

You should stay home on the first day of the installation so your installers can explain the process to you, and agree on a route for the cable to travel from your inverter to your electricity meter.

✅ Solar panels are fixed to your roof without damaging any tiles

Installers fix solar panels to a roof by attaching mounting rails to the roof, then securing panels to these rails.

They’ll then lift up some roof tiles and attach the mounting brackets to the rafters with roof hooks, before carefully placing the tiles back where they were.

This ensures that your panels are properly secured to the roof without damaging any part of it.

💷 After installation, you can sign up for a solar export tariff

Once your solar & battery system has been commissioned, connected to your smart meter, and certified by the MCS or Flexi-Orb, the next step is to sign up to a solar export tariff.

Have a look through our list of the best export tariffs, pick your favourite, and fill in the relevant application form.

You or your chosen export tariff provider must then ask your DNO for an export MPAN (Meter Point Administration Number) – a unique, 13-digit number that identifies your meter.

Your DNO will typically take one to four weeks to provide your export MPAN, after which point you’ll just have to send your export tariff supplier a meter reading.

When you’re thinking of getting solar panels, you’ll want to know how the installation will impact your everyday life and your home.

Thankfully, when you choose a good installer, the process is short and comes with as little disruption as possible.

In this guide, we’ll explain a typical solar panel installation from start to finish, as well as what all the hardware does, and where on your property you can install the panels.

If you’re interested in how much you could save with a solar & battery system, click the button below, enter a few details, and we’ll generate an estimate.

The solar panel installation process: explained

Installing solar panels is usually relatively quick and straightforward, but it’s still worth getting to know all the ins and outs of how it happens.

After all, considering how much solar panels cost upfront – unless you opt for a solar subscription like Sunsave Plus, of course – it makes sense to understand the process.

Here are all the steps your chosen installer will take to get the best solar panel system possible on your roof.

  1. Check if you need planning permission
  2. Property assessment & survey
  3. System design
  4. Property modifications
  5. Kit delivery
  6. Scaffolding erection
  7. Installation day(s)
  8. Testing and activation
  9. G99 approval
  10. Registering for a solar export tariff
  11. Monitoring and maintenance

1. Check if you need planning permission

Most households in the UK don’t need planning permission to get solar panels installed.

Rooftop solar almost always falls under the owner’s permitted development rights, which allow you to make reasonably sized improvements to your home without planning permission.

The key exceptions are typically flats, listed buildings, ground-mounted installations, and homes in conservation areas.

It’s worth finding out whether you need planning permission before you start the installation process.

Verified expert

The ideal property for solar panels would have a decent amount of space on its roof - typically we look for homes that can manage at least eight panels, but ideally it should be able to fit ten or more. It’s best for a roof to be south-facing, but in some cases it’s actually better with east-west roofs, as you can get more panels on.

Alfie Ireland, head of Operations & Technical at Sunsave

Alfie Ireland

Head of Operations & Technical

Alfie has worked in green tech for over a decade. During his four years at OVO, he helped develop the world’s largest domestic vehicle-to-grid trial.

2. Property assessment & survey

After you’ve initially shown interest in a solar installer’s services, the company should arrange for an expert to carry out a remote assessment of your roof.

This specialist will evaluate the roof’s condition, orientation, and incline, as well as how shaded it is and how much available space it has.

The great majority of UK roofs can comfortably hold a solar panel system’s weight, which is usually around 20kg per square metre.

In-person structural surveys are not usually necessary, but you will probably need one if you have a hipped roof, vaulted ceiling, or flat roof, and a good installer should arrange this.

The next step is usually a remote video survey of your home. This is just as effective and comprehensive as an in-person survey, with the added convenience that it can happen much quicker, as you don't have to schedule someone to visit your property.

Your installer may ask you to start in the loft, as it's where your DC cable will enter your home to link your solar panels with your inverter.

It also could be where your solar battery and inverter will live, as long as you have a gable end wall where the battery can be mounted and boards laid across the loft floor to help your installers safely move equipment around.

If your loft is otherwise suitable but doesn't have any boards, you can either choose an alternative place for your battery and inverter, or get some boards. You can lay them yourself, or hire someone to do it for you.

The installer will also ask you to take measurements and photos of the space, and particularly your loft hatch, to check it's big enough.

If you can’t get into your loft, you might have to take steps to allow you or someone else to access it, for example by borrowing a ladder from a neighbour.

For more information, check out our guide to whether your roof is suitable for solar panels.

3. System design

Based on what they’ve seen during the remote survey, your installer will then design your solar panel system.

They’ll decide on the number of panels, their angle and location on your roof, and which inverter, mounting system, and wiring configurations they’ll use.

They should also explain how this plan will affect the type and complexity of the scaffolding you’ll need for the installation, as well as the price.

A good installer will stay in conversation with you throughout this process, so when they present their final design and quote, it should match your specifications.

Feel free to ask them to change their design, and once you’re happy, you can give the go-ahead to move onto the next stage.

Two installers carrying a black solar panel along some scaffolding, in front of a house's roof

4. Property modifications

An installer will usually put your battery and inverter in a garage or under the stairs, in which case you won’t need to change anything.

But if they decide the loft is the most suitable location, you may have to add boards to your loft, and if your hatch isn’t big enough to let installers, a battery, and an inverter up there, you may want to make it larger.

You might also want to cut back trees and plants that would cast shade over your solar panels, so your system can turn as much sunlight into electricity as possible.

However, most homeowners won’t have to make any property modifications to create the ideal conditions for a solar panel system.

5. Kit delivery

You’re now ready to receive your kit.

Your solar installer will typically make the delivery in the week before the installation, so make sure you clear a space to store all the equipment you’re acquiring.

Point the workers delivering your gear in the right direction, and let them do the rest.

6. Scaffolding erection

Scaffolding will be erected around your home four or five days before the installation.

It’ll then usually be taken down around five days after it’s over – unless you have a particularly conscientious installer.

In this case, they’ll leave the scaffolding up for one to two weeks, because if anything goes wrong, you won’t have to pay for scaffolding to be constructed all over again.

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7. Installation day(s)

After all this build-up, your installation will be over before you know it, with most jobs taking between one and three days.

How much time it takes to install your system will largely depend on its size and complexity.

Before the team arrives, make sure they can access your loft, consumer unit (also known as a fuse box), and fuse, as well as any routes between these locations.

You should stay home on the first day of the installation so your installers can explain the process to you, and agree on a route for the cable to travel from your inverter to your electricity meter.

Make sure you’re also around to let the team into your home each day, and be sure to pass on your wifi password to the installers so they can commission the battery – that is, run through all the necessary system tests to check it’s working properly.

They’ll then need 10 minutes of your time to show you how to set up an account on your computer and phone, and how to use that account to monitor your system remotely.

However, you don’t have to be home for the hour or so in which the installers will have to turn the electricity off to safely connect the equipment, or for the remainder of the installation, when they’ll be intermittently making noise with tools.

How are solar panels fixed to the roof?

Installers fix solar panels to a roof by attaching mounting rails to the roof, then securing panels to these rails.

They’ll then lift up some roof tiles and attach the mounting brackets to the rafters with roof hooks, before carefully placing the tiles back where they were.

This ensures that your panels are properly secured to the roof without damaging any part of it.

Some slate tiles are too brittle to rest on a roof hook, in which case an installer will drill a small hole through the tile and into the rafter, to create a route for the roof hook.

If you’ve chosen to get bird proofing with your installation, it’ll be added at this point, when the panels are attached to your roof.

Where do the battery and inverter go?

Your garage, a cupboard under the stairs, or a protected external location are ideal places for batteries and inverters, as long as they’re spacious and air can move freely around the equipment, keeping them well-ventilated.

This is especially important for inverters, which can overheat otherwise.

Just keep them away from narrow alleyways – where air flow is limited – and out of public view to minimise the risk of theft.

You can also have your battery and inverter installed in the loft, as long as it contains a gable end wall, boards on the floor, and a large enough hatch. If your battery is especially heavy though, your team of installers may not be able to carry it upstairs.

Some homes – like terraced houses with a converted loft – may struggle to fit a battery and inverter in any of these places. In this case, you can put them in a hallway, as long as it doesn't block an escape route.

If you have a wall-mounted battery, your installer will identify a sturdy, load-bearing wall. If you don’t have one that works, you can always get a ground-mounted battery instead – though not in the loft.

Wherever your battery and inverter go, your installer should always place them one or two metres away from each other, regardless of whether the battery is AC-coupled or DC-coupled.

If you would like to see the savings you could get from a solar & battery system, click the button below. Just answer a few quick questions, and we’ll provide an estimate.

How is the cabling set up?

Your solar panel system will require three cables, all of which we’ll explain below.

For aesthetic reasons, a good installer will either run these outside or feed the cables through an existing internal conduit (i.e. a cavity in your property that already has cables running through it).

This should keep their visibility to a minimum.

Verified expert

Our cable runs are always done very neatly. We choose the shortest path between the solar equipment and the meter, and we conceal the cable in a nice plastic container called ‘trunking’. We will always aim to find a cable run that our customers are satisfied with.

Alfie Ireland, Head of Operations & Technical at Sunsave

Alfie Ireland

Head of Operations & Technical at Sunsave

Alfie has worked in green tech for over a decade. During his four years at OVO, he helped develop the world’s largest domestic vehicle-to-grid trial.

DC cable

The DC cable will take the electricity your panels generate to the inverter, which will convert it into AC electricity that you can use in your home or export to the grid.

Your installer will usually run this cable through the roof, into the loft. To achieve this, they’ll lift up your roof tiles, find the felt membrane underneath, then feed the cable between two sections of felt that overlap each other.

This way, the cable will be secured in place without tearing the felt.

The DC cable should ideally be no longer than 15 metres to make sure no electricity is lost during transmission, though anything up to 20 metres isn’t too much of an issue.

As well as losing electricity along the way, an overly long DC cable also presents more of a fire hazard. A DC cable will stay live even when damaged, so the more of it there is, the higher the risk.

Comms cable

The communication cable, commonly referred to as the comms cable, runs between the battery and your supply meter.

This cable shouldn’t be much longer than 35 metres, otherwise it may suffer delays and start sending inaccurate information to your meter.

As mentioned above, if your installer can’t run this outside, they should add it to an existing internal conduit.

AC cable

After the inverter has converted your solar panels’ DC electricity into AC electricity, the AC cable will take it to your PV distribution board – that is, a fuse box for your solar panels.

This distribution board is connected to the supply meter.

Your installer will either run the AC cable through the roof or find a place for it outside.

8. Testing and activation

Your team of installers will then test the entire system, to ensure it’s operating efficiently and safely.

They’ll check all the electrical connections are wired properly and performing their intended tasks, everything is securely fixed in place, and the installation matches the design, before moving to commission the system.

This means connecting your solar panel system to the grid, at which point the installation will be complete and the panels will fall under your control.

If you choose Sunsave Plus though, you’ll be covered by the Sunsave Guarantee, which provides 24/7 monitoring and maintenance.

9. G99 approval

Most solar households won’t require this step, but if your inverter’s maximum capacity is over 3.68kW on a single-phase system, you or your installer must send a G99 application to your area’s Distribution Network Operator (DNO).

Until your DNO’s approval arrives – which it usually will, within four to eight weeks – your installer will limit your inverter to 3.68kW. This is so your panels don’t export more electricity than the grid can handle.

A good installer can do this remotely, which means they can also remove the limit the moment your approval comes through.

10. Registering for a solar export tariff

Now that your solar panel system’s been commissioned, connected to your smart meter, and certified by the MCS or Flexi-Orb, the next step is to sign up to a solar export tariff.

Have a look through the best export tariffs, pick your favourite, and fill in the relevant application form.

You or your chosen export tariff provider must then ask your DNO for an export MPAN (Meter Point Administration Number) – a unique, 13-digit number that identifies your meter.

Your DNO will typically take one to four weeks to provide your export MPAN, after which point you’ll just have to send your export tariff supplier a meter reading.

The current best option is Intelligent Octopus Flux, a smart import and export tariff with the highest rates on the market that allows you to use your battery to maximise your income, instead of simply viewing it as a storage device.

We’ve partnered with Octopus to provide speedy access to Intelligent Octopus Flux – so if you sign up for Sunsave Plus, you can get to the front of the queue.

If you don’t use Sunsave’s fast-track assistance, you could be waiting up to 11 weeks to start profiting from Intelligent Octopus Flux.

11. Monitoring and maintenance

This is the most important post-installation step, as it’s the only way to ensure your system continues working properly over its decades-long lifespan.

Unfortunately, most installers don’t offer it – but Sunsave does, as part of Sunsave Plus.

This tailored solar & battery solution comes with the Sunsave Guarantee. That means 20 years of monitoring and maintenance, and free battery and inverter replacements, all for a monthly subscription at no upfront cost.

Our experts will keep track of your panels & battery for you 24/7 using our remote monitoring platform. They’ll spot any issues, inform you, and take the measures needed to fix them, all without you having to lift a finger.

If we can’t solve the issue remotely, a Sunsave engineer will visit your home within two weeks – and often much sooner.

There’s a callout fee of £100, but we cap this at a maximum of £200 per year, plus VAT. So even if you need more than two callouts in a year, your costs will be capped.

If your panels, battery, or inverter stop functioning before the end of their warranty, we’ll submit the relevant claims to the manufacturer, and install any replacement parts.

And once your battery has outlasted its typical lifespan of 10-12 years and is working at less than 70% of its original capacity, we’ll replace it with a new battery, for free. We’ll also do the same for your inverter.

If you’re not on Sunsave Plus, a solar battery costs around £5,000 when you’re adding it to a pre-existing system – and considering solar panels last at least 25 years, this is almost always a necessary step.

Your system will also come with insurance provided by Aviva, which insures you against theft, damage, and fire.

And if your system ever isn’t working properly, Sunsave Plus includes downtime cover, meaning we’ll cover your monthly payments while we fix the problem.

Installing solar panels in alternative places

Domestic solar panel systems are usually installed on roofs, since they’re generally the part of your property that receives the most sunlight, and they typically have few other uses.

But of course, it’s always worth considering your options before deciding where your panels should go.

Just be aware that non-rooftop panels will likely mean more planning permission obstacles, and more companies who aren’t comfortable with your plans.

Can you install solar panels on a barn?

You can install solar panels on a barn, as long as the roof is strong enough and you’re fine with keeping the battery and inverter inside the barn, so your DC cable doesn’t have far to travel.

However, if your barn is more than 35 metres from your house, your comms cable’s performance may be affected, and it could end up sending incorrect data to your meter.

Bear in mind that your installer will have to either run the comms cable along your fence, or dig a trench and run the cable underground – though this can cause more issues if you’ve paved any of the area between your barn and house.

One solution for this is to use a LoRa wireless transmitter and receiver to send information directly to your meter. It typically costs around £250, which is a lot cheaper – and less disruptive – than an installer digging a trench through your garden.

Can you install solar panels on a flat roof?

You can install solar panels on a flat roof, but it’s not usually a good idea for domestic properties.

Drilling into a flat roof is typically inadvisable, since any rain that falls may end up leaking into your home, so your installer would ballast the panels instead – but this massively raises the weight of a system, as ballasts weigh about 80kg per panel.

A fully-installed system with 12 solar panels usually weighs 240kg, which the average roof can easily support – but with ballasts, this figure increases to 1,200kg.

This is why most flat-roof solar arrays are installed on large commercial buildings with strong roofs.

Your system also won’t be as large as it would be on an equivalently sized pitched roof. Panels on a flat roof cast shade on each other, so you’ll have to space them out – meaning you’ll have to limit the number of panels you install.

If you move ahead, make sure you stay within planning permission guidelines. Your panels must not stick out more than 60cm from the roof’s surface, and no part of the installation can be more than four metres above the roof.

Can you install solar panels on the ground?

You can install ground-mounted solar panels, though you’ll again need more space than you would if you installed panels on a pitched roof.

This is because you’ll need to space out your panels so they don’t cast shade on each other, just like on a flat roof.

They’re therefore usually more suitable for commercial purposes, as most households don’t own the amount of unshaded land that’s ideally required.

The installation process doesn’t involve scaffolding, which cuts down on costs, but you’ll still need to provide the solid foundation that a roof usually supplies.

This can take the form of pile-driven poles or concrete footings, but either way, it’s pretty expensive.

You’ll also need a mounting structure to hold each panel in place. These are usually made of metal, but wooden and plastic options are available.

Most ground-mounted solar panel projects also require planning permission. Get in touch with your local authority if your planned installation is:

  • Composed of more than one solar panel
  • Within five metres of your property’s boundary
  • Larger than nine square metres
  • Higher than four metres at any point
  • More than three metres wide or deep at any point

If you add to your ground-mounted array at any point in the future, make sure you apply for planning permission again.

Can I install solar panels myself?

We wouldn’t recommend installing solar panels yourself, for both practical and safety reasons.

DIY installations pose risks and may lead to improper functioning – plus it’s very unlikely that a self-installed solar panel system will get certified under the Microgeneration Certification Scheme (MCS).

Without an MCS certification, you won’t be eligible for smart export tariffs that allow you to sell your surplus electricity to the grid.

When you hire qualified professionals, you’ll get a secure, efficient, certified solar energy system that should ensure your panels work as well as possible. 

This will benefit you financially, make it easier to sell your property, and increase the value of your home.

Summary

Your solar panel system installation should be quick, efficient, and minimally disruptive to your life and home.

To make sure your panels go up without too much fuss – and are set up to generate the most electricity possible – you should hire an accredited, certified installer, like Sunsave.

If you’re wondering how much a solar & battery system could save you, answer a few quick questions below and we’ll provide you with an estimate.

Solar panel installation: FAQs

How do they attach solar panels to the roof?

First, installers put in mounting brackets – the anchors that hold everything in place. They're carefully aligned and secured to your roof's rafters for a strong grip. After this, the solar panels are attached to these brackets using a rail system.

This setup allows the panels to sit securely on your roof and withstand things like strong winds or heavy rain. It's all done with care to minimise the risk of damage to your roof and to make sure the panels stay put for years to come.

How are solar panels connected to the house?

First, the panels on your roof capture daylight and convert it into DC (direct current) electricity. This electricity is still in a form your house can't use, so it goes through an inverter that transforms it into the AC (alternating current) electricity we use at home.

This usable electricity is sent through your home's electrical panel, powering your lights, air fryer, TV – you name it. Any extra power can either be stored in a solar battery for later use or sent back to the grid for extra cash.

Does solar panel installation include bird protection?

At Sunsave, we give you the option to add bird protection to your solar panels.

However, it is not always a necessary step, as it depends on whether you live in an area with lots of birds. Also, if you opt for Sunsave Plus, your system is covered by the Sunsave Guarantee, which includes insurance protection (provided by Aviva) against damage caused by birds.

Does a solar panel installation damage your roof?

A professionally implemented solar panel installation should not damage your roof.

The only situation in which a properly accredited and certified installer will damage any part of your roof is if you have slate tiles that can’t sit on a roof hook without breaking, in which case they’ll drill a small hole through the tile and into the rafter.

Of course, even the best installers can make mistakes. If any part of your roof is broken during your solar panel installation, the company should fix it or fully compensate you for the damage before the end of the project.

Do you need scaffolding to install solar panels?

You’ll need scaffolding to install solar panels on a pitched roof.

The temporary structure will allow your installation team to safely carry all the necessary heavy equipment, including the panels and mounting gear, up to your roof.

Depending on your building’s structure, you may not need scaffolding for flat roof solar panels, while you certainly won’t need scaffolding for ground-mounted panels.

How long does a solar panel installation take?

A solar panel installation usually takes between one and three days.

If the job is more complex, for instance if the roof is hard to access, it can take another day or two.

After this point, a good installer like Sunsave will leave the scaffolding up for a while longer – usually a week or two – just so that if anything goes wrong, an engineer can easily access the system and fix the issue.

Will your property have power during a solar panel installation?

Your property will have power during a solar panel installation, for all but a short period.

The installer will shut off the power to safely connect your new hardware to your home’s electricity supply, but this should only last around an hour.

For the rest of the day or two of the installation process, you’ll have power.

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Written byJosh Jackman

Josh has written about the rapid rise of home solar for the past five years. His data-driven work has been featured in United Nations and World Health Organisation documents, as well as publications including The Eco Experts, Financial Times, The Independent, The Telegraph, The Times, and The Sun. Josh has also been interviewed as a renewables expert on BBC One’s Rip-Off Britain, ITV1’s Tonight show, and BBC Radio 4 and 5.

Copyright © 2024 Sunsave

Sunsave Group Limited (company number: 13741813) and its affiliates, Sunsave UK Limited (company number: 13941186) and Sunsave Energy Limited (company number: 13952135), together trading as “Sunsave”, provide renewable energy systems and finance and are registered at 71-75 Shelton Street, Covent Garden, London, WC2H 9JQ. Sunsave UK Limited (FRN: 1008450) is a credit broker and can introduce you to a panel of lenders for the purpose of arranging finance. Sunsave Energy Limited (FRN: 979494) is a lender. Both Sunsave UK Limited and Sunsave Energy Limited are authorised and regulated by the Financial Conduct Authority.