Types of Solar Panels: Mono, Poly & Thin Film Explained

Efficiency: 20–22% (best residential option) Appearance: Uniform dark black or dark blue Lifespan: 25–30+ years Cost: £200–£350 per panel (400–450W) Best for: UK homes where roof space is limited and maximum output per panel matters

Advantages: - Highest efficiency — fewer panels needed for the same output - Best low-light performance — captures more energy on cloudy UK days - Longest lifespan and slowest degradation - Sleek, uniform appearance

Disadvantages: - Slightly more expensive per panel than polycrystalline - Production process uses more energy (though this is offset by higher lifetime output)

Top monocrystalline brands: SunPower (22.8%), REC Alpha (21.7%), LG NeON (21.4%), Longi Hi-MO (21.3%), JA Solar (21.0%)

Source: Manufacturer datasheets; IEC 61215 certified specifications.

Efficiency: 15–17% Appearance: Blue with a visible crystal pattern Lifespan: 25+ years Cost: £150–£250 per panel (350–400W) Best for: Budget installations where roof space is not a constraint

Advantages: - Lower cost per panel - Proven, reliable technology - Slightly simpler manufacturing process

Disadvantages: - Lower efficiency — need more panels for the same output - Poorer low-light performance than monocrystalline - Less aesthetically pleasing (blue, speckled appearance) - Declining market share — many manufacturers now focus on monocrystalline

In 2026, the price difference between mono and poly is typically less than £50 per panel. Given the higher efficiency and better low-light performance of monocrystalline, polycrystalline panels are hard to recommend for new UK installations unless budget is extremely tight.

Source: Solar Energy UK market data; manufacturer pricing.

Efficiency: 10–13% Appearance: Uniform dark surface, very slim profile Lifespan: 15–20 years (shorter than crystalline) Cost: Varies — often used in commercial/specialist applications Best for: Large commercial roofs, building-integrated PV (BIPV), curved surfaces

Thin-film panels are not commonly used in UK residential installations. They are made by depositing thin layers of photovoltaic material onto a substrate (glass, metal, or plastic). Technologies include CdTe (cadmium telluride), CIGS (copper indium gallium selenide), and amorphous silicon.

Advantages: - Lightweight and flexible - Can be integrated into building materials (roof tiles, facades) - Better performance in very hot climates (less relevant to UK) - Uniform appearance

Disadvantages: - Much lower efficiency — need roughly twice the roof area for the same output - Shorter lifespan than crystalline panels - Limited availability from UK residential installers - Not cost-effective for most UK homes

Unless you have a specific reason (curved roof, building-integrated design, or a very large commercial roof), thin-film is not recommended for UK residential use.

Source: NREL solar cell efficiency chart; IEC testing standards.

For almost every UK homeowner in 2026, the answer is monocrystalline. Here is why:

- The price gap with polycrystalline has nearly closed (less than £50/panel difference) - Higher efficiency means fewer panels needed — critical on smaller UK roofs - Better cloudy-day performance — important in the UK climate - Longer effective lifespan and slower degradation - Most UK installers now only offer monocrystalline as standard

The only exception: if you have a very large roof (e.g. agricultural building, warehouse) and budget is the primary concern, polycrystalline may still make sense due to slightly lower cost per panel.

For residential UK installations: choose monocrystalline. Do not overthink it.