James Elston

James Elston

Published May 31, 2024

Yes, solar panels can be installed efficiently and safely on a slate roof. Slate is a good surface that supports a secure rack mounting. However, installing solar on slate roofs is more complicated compared to other roof types. Slate is more brittle than most other roofing materials and must be handled with care.

This makes fitting solar panels on a slate roof more challenging. Installers must take extra precautions and spend more time on-site. Special equipment and materials are needed. The installation will likely take a day or two longer and cost around 20% to 30% more than a standard job.

If you are considering a solar project and wondering can solar panels be installed on a slate roof, we have all the answers for you. Read on for a breakdown of the installation process, costs involved, and important solar considerations. We also look at alternate ways to secure solar on slate roofs.

How Are Solar Panels Installed On A Slate Roof?

Installing a solar panel system on a slate roof involves securing mounting racks on the roof structure, fitting solar panels onto the racks, and connecting cables from the panels to the inverter. The inverter converts the DC solar electricity into the AC electricity that powers your appliances. Let’s look at 10 essential installation steps in more detail.

Step 1: Professional assessment

A professional assessment of your property is the vital first step. A certified solar installation company will advise how many solar panels you require to meet your energy expectations. Their assessment will also confirm that your roof is suitable for solar. In the UK, unshaded south-facing roofs with a steepness of between 30 and 40 degrees are best placed to capture the sun’s energy.

Unshaded east and west-facing structures also work; north-facing roofs will produce considerably less electricity.

The professional evaluation should advise the best layout design and the type, size, and array of panels.

Step 2: Preparation and marking the installation area

On most jobs, scaffolding is installed to create safer, more convenient access to the roof.

The area where the panels will be installed is marked. On slate roofs, many installers use a humble piece of chalk to outline the position of this fairly advanced renewable energy system.

Step 3: Remove selected slates

Selected slates are removed using a slate ripper or a special saw. The slates are carefully levered free and set aside. Removing these slates provides access to the roof rafters.

Step 4: Secure the mounting brackets

Mounting brackets are attached to the roof rafters usually with stainless steel screws.

Step 5: Fix flashing sheets

Plastic or lead flashing is fixed at each anchor point to provide effective waterproofing around the mounting brackets. Proper waterproofing is crucial to prevent leaks and water damage, especially on roofs with a steep slope like many slate roofs.

Step 6: Replace the slates

The removed slates are replaced around the brackets. Slates are cut with a slate saw where necessary to ensure they fit tightly over the flashing and around the bracket racks.

Step 7: Attach the rails

Rails are then fixed to the anchor racks for the solar panels to be mounted on.

Step 8: Install the panels

The solar panels are lifted onto the roof, fitted onto the rails, and secured in place. The solar panels are connected in series or parallel per the system design. The connectors are waterproof to protect the system.

Bird-proofing: Some installations include a protective barrier made of mesh or other material to prevent pigeons from nesting under the panels. Nests can compromise panel efficiency and birds may damage cabling and connections.

Step 9: Connect the inverter

Cables are routed to connect the panels and your inverter. The inverter must be connected to your fuse board.

If you opt for a storage battery this is also connected to the system.

Step 10: Connect the battery

When installing solar panels it’s a good idea to consider a solar battery. Currently, there is 0% VAT on batteries installed in homes and some businesses as part of a solar system. Solar panels are also zero VAT rated.

Most solar energy is produced in the middle of the day when the sun’s rays are strongest. This doesn’t align with most households’ needs since homes usually consume more energy in the early morning and the evening. This is where a solar battery comes in handy. Excess energy produced during the day can be stored in the battery for later usage.

How Long Does It Take to Install Solar Panels On A Slate Roof?

The time it takes to install solar panels on a slate roof varies from job to job depending on the size and complexity of the installation. Generally, a home solar panel installation will take three or four days. This is longer than the two days required for an asphalt shingle or metal roof. Larger, difficult jobs may take over a week.

The following factors influence the job’s duration:

  • The number of panels installed.
  • The number of installers on the job.
  • The difficulty of the roof as a working surface and the condition of the slate.
  • Possible challenges with running cable from the panels to the inverter.
  • The time to set up scaffolding (this can take half a day or longer).
  • If additional fixtures such as an Electric Vehicle charger, solar batteries, and anti-bird barriers are included overall installation time will be longer.

How Much Does It Cost to Install Solar Panels On Slate Roofs?

The average cost of installing solar panels on a slate roof ranges from £6,000 to £13,000+ depending on factors relating to the property and the solar system. This excludes a battery.

Property factors include:

  • Your monthly electricity consumption in kWh- which you will find on your bill.
  • The property and roof size.
  • How well your roof harnesses the sun. A north-facing roof needs a larger installation than a south-facing roof, for example.

Solar variables include:

  • The number of panels required.
  • Size of the panels in wattage. The panels in residential solar systems usually range from 300W to a little over 400W. The more powerful the panels the fewer you need.
  • Efficiency and quality of the panels.
  • Installation costs.

The inverter costs from £700 up to £1,600. This is usually included in the overall price when installing solar panels.

Bearing in mind that costs differ from home to home here are approximate indications for installing solar panels on slate roofs. Because a storage battery isn’t always included in a solar setup the battery cost is shown separately.

House SizeAnnual Electricity
Solar Panel
System kWh Output
No. of Solar Panels
Solar Battery Cost
1 bedroom<2,000 kWh3kWh6-8£6,000 – £7,500£2,000 – £2,500
2 bedroom2,000-2,900 kWh3.5 kWh – 4kWh8-10£7,500 – £8,500£2,500 – £3,000
3-4 bedroom3,000 – 5,000 kWh5kWh10-16£8,500- £10,500£3,000 – £4,500
5 or more bedrooms5,000 – 8,000 kWh6kWh16-20£10,000 – £13,000+£4,500 – £7,000+

While the capital outlay for solar is expensive here are incentives and other reasons suggesting that solar panels are worth it.

Are there grant schemes available for solar panel installation?

Yes. There are several grants aimed at helping homeowners install solar. You may qualify for financial assistance under one of the following schemes:

Energy Company Obligation 4 (ECO4): This scheme runs to March 2026 and may offer eligible households in England, Scotland, or Wales financial support for solar projects.

Home Upgrade Grant (HUG2): This grant is aimed at low-income households, particularly those off-grid. The scheme is available until March 2025 and could fund up to £10,000.

Home Energy Scotland Grant and Loan Schemes: All households in Scotland could be eligible for up to £6,000 to assist with installing solar technologies.

Smart Export Guarantee

The Smart Export Guarantee (SEG) is a government-backed initiative that lets you sell excess electricity you generate back to the national grid. The amount you receive for exporting electricity varies according to the supplier. It is usually less than the amount you pay to buy electricity but is nonetheless a nice little earner.

Your solar system must be installed by a certified Microgeneration Certification Scheme (MCS) installer to qualify for SEG.

Solar ROI

Many experts agree that solar offers a compelling Return on Investment (ROI), paying for itself in under 10 years. More conservative Energy Saving Trust figures show savings of about £500 annually (with SEG). This suggests a £7,000 installation will pay for itself in 14 years. Meanwhile, your panels should last for over 20 years.

Most people expect electricity prices to go up which means a faster payback period. In addition, solar future-proofs your home and increases its value.

Are There Other Solar Panel Options for a Slate Roof?

Yes, there are a few different ways to integrate solar into a slate roof. Let’s explore the most popular options.

Integrated solar panels

Property owners who value their slate roof’s appearance may be reluctant to compromise the look with a raised solar setup.

Integrated solar panels (or in-roof solar panels) offer a solution These panels are designed to be installed within the structure of your roof. A section of tiling is removed and the integrated solar panels are laid in this space. They lie flush on the roof alongside your slate tiles.

These integrated panels are suitable for various roof pitches from 15 to 50 degrees and are durable and waterproof.

Installing in-roof solar panels costs approximately the same, or even a little less, than installing on-roof solar. However, integrated panels are up to 20% less energy-efficient than conventionally mounted panels because there is no airflow beneath them to aid efficient cooling. This means they don’t generate as much electricity as a raised array of the same size.

Solar tiles

Solar tiles are designed to blend in with your roof even more seamlessly than integrated panels. They are small and shaped to resemble normal tiles or slate. The idea is to achieve a flush, aesthetically pleasing finish.

Solar tiles are currently around 1.5 times more expensive than solar panels and are less efficient because of the lack of ventilation and their small surface area. They are tough and resilient, able to withstand hail, extreme weather conditions, and ‘vandalism’ by birds.

Installing the tiles involves removing existing slate sections and replacing them with solar units.

Replacing your slate tiles

Some homeowners opt to replace their slate tiles and upgrade their roofs at the same time as they install solar. This may be a consideration if your slate is old, cracked, or broken, or if you want to refresh the property’s appearance. Of course, this is the most expensive route to go.

There are attractive alternatives to slate including clay tiles. Other alternatives that are very well-suited to solar installations include asphalt shingles, metal, and rubber membrane roofing.

Solar panels are easily and effectively installed when the roofing contractors and solar installers coordinate the new roof design together.

Get A Solar Panel Installation Quote Today

Securing greater energy independence, reducing your carbon footprint, and lowering your electricity bills are excellent reasons to install solar panels whatever your roof type.

There were more than 183,000 solar panel installations in the UK in 2023, up a third from 2022. As solar experts, Eco Happy has helped hundreds of property owners achieve successful solar panel installations. We’d be delighted to guide you to find the right solar solution for your home.

It’s an exciting time to be installing solar panels. If you’re ready to get started contact Eco Happy or simply complete our quick online form for a free, no-obligation solar installation quote. Join the hundreds of thousands of property owners experiencing the benefits of clean, renewable affordable energy.


Are slate roofs strong enough to carry solar panels?

Most slate roofs can safely support the weight of an appropriate solar installation. However, a qualified roofing professional should be consulted before proceeding with a solar project. A professional evaluation will confirm that your property and slate roof have the structural integrity to accommodate the solar array. It will also advise the best way to harness the sun’s energy.

What type of roof is best for solar panels?

Asphalt shingle roofs are considered the best for solar panels because they are durable and typically have a lifespan of 20 -30 years. It is easy to drill and secure mounts for solar panels on this type of roofing.

Can solar panels be installed on any roof type?

Solar panels can be installed on most roof types. There are a few exceptions like thatch and wooden shingle roofs that are not suitable for solar because of concerns over fire safety.

Our Verdict

Installing solar panels on a slate roof is a little more labour-intensive and expensive than fitting solar on more regular roofing material. A slate roof installation may cost 25% more than other roofing materials.

Exact installation costs depend on how many panels you need to deliver the property’s electricity demands. Your roof’s size, configuration, position, and pitch also impact the price – which ranges from approximately £6,000 for a 1-bedroom home to £13,000 for a 5-bedroom household (excluding battery).

Government incentives such as ECO4 and HUG2 offer financial subsidies to encourage homeowners to invest in solar. Thousands are choosing to upgrade their properties and lower their bills by taking advantage of solar’s clean, renewable energy.

James Elston

James Elston

Boiler Expert

James Elston is the top boiler replacement and heating expert at Eco Happy. He has over 20 years of experience in the industry, focusing on Gas Safe boiler installations and offering home-heating and energy-saving solutions to homeowners across the UK. From sourcing the most energy-efficient combi boiler to providing specialist heating advice, James ensures that Eco Happy maintains the highest standards and best customer service.

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