What are the different types of solar panels? Rooftop, plug-in and PV technologies explained

Solar panels may all perform the same basic job, turning sunlight into electricity, but there are important differences between the technologies and systems now available to UK households.

For most homeowners installing conventional rooftop solar panels, monocrystalline panels are now the standard choice. They combine high efficiency with strong power output from a relatively small roof area, while older polycrystalline technology is increasingly difficult to find. Within the monocrystalline category, newer cell technologies such as TOPCon and HJT are also pushing efficiencies higher.

The options are broadening beyond conventional rooftop systems, too. Since August 2026, compliant plug-in solar panels have been legal in Great Britain, offering renters and households without a suitable space a lower-cost way to generate some of their own electricity.

In this guide, we explain the main types of solar panels available in the UK, how technologies such as monocrystalline, thin-film, TOPCon and HJT differ, and which type is likely to be best for your home.

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What are the main types of solar panels?

When people talk about the different types of solar panels, they are often referring to two slightly different things: the technology used inside the panel and the way the solar system is installed.

Solar panel technologies include monocrystalline, polycrystalline and thin-film panels. These terms describe the materials and manufacturing methods used in the photovoltaic cells, which affect their efficiency, cost and typical uses.

Solar system types, meanwhile, describe how solar is fitted or used around the home. This includes conventional rooftop solar panels, plug-in solar panels, solar tiles, flexible solar panels and building-integrated photovoltaics. A plug-in solar system, for example, may still use conventional PV technology, but it is designed for a very different purpose from a full rooftop installation.

Below, we’ll break down the different types of solar panel technology and then the different types of systems you can install.

Types of solar panel technologies

Monocrystalline solar panels

Monocrystalline panels are now the standard choice for most UK homes. Made using cells cut from single-crystal silicon, these convert sunlight into electricity more efficiently than older polycrystalline designs. You can spot them because they usually have a uniform black appearance.

Modern monocrystalline panels typically achieve efficiency ratings of around 20 to 24 per cent, although some premium models are even more efficient. This means they can generate more electricity from a limited roof area, making them particularly suitable for UK homes where space is often at a premium.

While monocrystalline panels were once noticeably more expensive than polycrystalline alternatives, the price difference has narrowed considerably. They now dominate the domestic solar market, with manufacturers offering a wide range of products at different prices and performance levels.

Newer monocrystalline cell technologies, including TOPCon and HJT, offer further improvements in efficiency and long-term performance. Most modern panels also come with performance warranties lasting 25 to 30 years, although product warranties vary between manufacturers.

Best for

• Most UK households
• Smaller or space-constrained roofs
• Homeowners focused on long-term performance

Polycrystalline solar panels

Polycrystalline panels are made using silicon containing multiple crystals rather than the single-crystal structure found in monocrystalline panels. These panels are usually recognisable by their blue, speckled appearance.

Polycrystalline panels typically achieve efficiency ratings of around 15 to 18 per cent, meaning they need more roof space to generate the same amount of electricity as a modern monocrystalline system.

These panels were once a popular, lower-cost alternative to monocrystalline solar; however, advances in manufacturing have made monocrystalline panels much more affordable, and their superior efficiency means fewer panels are needed to achieve the same output.

As a result, polycrystalline panels are increasingly being phased out and are now rarely offered for new domestic installations in the UK, if at all. Homeowners comparing quotes will generally find that monocrystalline panels offer much better value for money.

Best for

• Existing installations using polycrystalline technology
• Situations where compatible replacement panels are needed
• Specialist projects where older panel stock is available at a significant discount

Thin-film solar panels

Thin-film solar panels are produced by applying thin layers of photovoltaic material to surfaces such as glass or metal. They are lighter and more flexible than silicon panels and their main advantage is versatility. Some thin-film products can be installed on curved, lightweight or unconventional surfaces where rigid solar panels would be impractical.

However, thin-film panels generally produce less electricity per square metre than modern monocrystalline panels, although efficiency varies considerably between technologies and manufacturers. This means they often need a larger surface area to generate the same amount of electricity.

Thin-film products also vary in durability and warranty coverage, so homeowners should compare individual specifications rather than assuming all thin-film panels have a shorter lifespan.

For most domestic rooftop installations in the UK, monocrystalline panels remain the more practical option. Thin-film technology is generally better suited to commercial, industrial or specialist applications.

Best for

• Commercial and industrial installations
• Large, unobstructed surfaces
• Lightweight, curved or non-standard structures
• Specialist applications where conventional rigid panels are unsuitable

Types of solar panel technologies compared

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Types of solar panel systems

As well as choosing a panel technology, homeowners may also come across different solar system types. These are not always separate technologies; in many cases, they describe how the panels are installed, connected or integrated into the property.

For most UK homeowners, a standard rooftop solar PV system remains the most common option. However, plug-in solar panels, solar tiles and flexible solar panels may suit households with different priorities, budgets or property constraints.

Rooftop solar panels

Rooftop solar panels are the most common form of domestic solar installation in the UK. Panels are mounted on the roof and connected to an inverter, which converts the electricity they produce into power the home can use.

A rooftop solar system will usually cost more upfront than a small plug-in kit, but it can generate significantly more electricity and deliver greater long-term savings. For homeowners with a suitable roof, this is still likely to be the main option to consider.

Best for

• Homeowners with suitable roof space
• Households with higher electricity use
• People looking for the largest bill savings from solar.

Plug-in solar panels

Plug-in solar panels became legal to buy and use in Great Britain on 27 August 2026, giving households another way to generate their own electricity without installing a conventional rooftop solar system.

These smaller systems typically use one or two solar panels connected to a microinverter, which converts the electricity into AC power before feeding it into your home's electrical system through a standard socket. Under the current rules, compliant plug-in solar devices are limited to an AC output of 800W.

Their main advantage is accessibility. They can be self-installed according to the manufacturer's instructions and may suit renters and people who cannot install a conventional rooftop array. Energy Saving Trust estimates an 800W system could save around £70 to £100 a year, depending on how much of its electricity you use while it is being generated.

However, plug-in solar produces much less electricity than a typical rooftop installation and shouldn't be regarded as a direct replacement. Renters and flat owners may also need permission from a landlord or freeholder, and the current rules don’t cover plug-in systems with integrated battery storage. Plug-in solar is currently legal in England, Scotland and Wales, but not Northern Ireland.

Best for

• Renters and homeowners who can’t install rooftop solar
• Homes with a suitable garden, patio or other outdoor space
• Households that use electricity during daylight hours
• People looking for a lower-cost entry into solar generation

Solar tiles and building-integrated photovoltaics

Solar tiles, sometimes called solar roof tiles, are designed to replace conventional roof tiles rather than sit on top of them. Building-integrated photovoltaics (BIPV) work on a similar principle, incorporating solar generation directly into elements of a building, such as its roof or façade.

These systems have a more discreet appearance than conventional rooftop panels and may appeal to homeowners planning a new build or roof replacement. However, they are generally more expensive and may produce less electricity per square metre than standard monocrystalline panels.

Solar tiles can also be appealing for properties where appearance is particularly important, although listed buildings and properties in some protected areas may require additional planning permission or consent.

Best for

• New builds, roof replacements
• Listed or design-sensitive properties where appearance is a major consideration

Flexible solar panels

Flexible solar panels are lightweight panels that can bend slightly, making them useful for curved or weight-sensitive surfaces. They are more commonly used on caravans, boats, sheds and outbuildings than on standard domestic roofs.

Their main advantage is versatility, but they are typically less efficient and may not last as long as rigid framed solar panels.

Best for

• Caravans, boats, sheds, outbuildings and lightweight structures where rigid panels are not practical

Solar panel system types compared

Which type of solar panel is best for UK homes?

For most UK homeowners, monocrystalline rooftop solar panels remain the best all-round choice. They offer high efficiency, strong electricity generation from limited roof space and good long-term performance. They are also widely available, with models to suit different budgets and property requirements.

When comparing monocrystalline panels, it's worth looking beyond the headline higher efficiency figure. Newer cell technologies such as TOPCon and HJT can offer improved performance, but the panel's power output, warranty, degradation rate and overall installation cost are equally important.

However, the best type of solar system also depends on your property. Plug-in solar panels may be more practical for renters, flat owners or households without suitable roof space. Solar tiles can be an option for homeowners replacing a roof or prioritising appearance, while flexible solar panels are generally better suited to caravans, boats and specialist structures.

For most households considering a conventional rooftop installation, the choice is therefore less about monocrystalline versus polycrystalline panels and more about which modern monocrystalline panel offers the best combination of performance, warranty and price.

Other solar panel “types” you’ll see (and what they actually mean)

Beyond monocrystalline, polycrystalline and thin-film technologies, you’ll often see extra labels in installer quotes and product spec sheets. These don’t usually describe a completely different type of solar panel. Instead, they’re typically a thin-film material, a panel design feature, or a cell technology used inside a monocrystalline panel.

Thin-film subtypes: different materials, same category

Thin-film panels are sometimes broken down by the material used, such as amorphous silicon (a-Si), cadmium telluride (CdTe), or CIGS. These can affect efficiency and cost, but they’re still all “thin-film,” and thin-film remains a niche choice for most UK homes compared with monocrystalline solar panels.

“Bifacial” panels: a design feature, not a new panel type

Bifacial panels can generate electricity from both the front and the rear, with the idea being that any light being reflected off the roof underneath the panel can also be converted into electricity. In the right setup (for example, mounted above a light-coloured surface that reflects sunlight), they can produce more energy than a standard solar panel. The key point is that bifacial is usually an add-on design to monocrystalline panels, not a separate technology category.

Half-cut, shingled and “black frame”: build and aesthetics

You may see solar panels described as half-cut or shingled. These refer to how the cells are arranged and wired, which can improve performance in partial shade and reduce electrical losses. Likewise, “all-black” or “black frame” is mainly an appearance choice. Again, these are typically variations of monocrystalline panels, not distinct solar panel types.

PERC, TOPCon, HJT, IBC: cell technology labels

These acronyms describe how the solar cells are engineered. They can affect real-world performance (especially in lower light), but they’re best thought of as generations of monocrystalline tech, rather than a fourth or fifth solar panel type. If you’re comparing quotes, they’re useful as a sign that you’re looking at newer designs, but efficiency, warranty, and cost-per-watt still matter more than the acronym alone.

Solar thermal: not the same as solar PV

Finally, it’s worth separating solar PV (which generates electricity) from solar thermal systems, which use roof-mounted collectors to heat water. Solar thermal is useful in the right home, but it isn’t a type of electricity-generating solar panel.

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