Our top picks at a glance
- Best overall: REC Alpha Pure-RX, 22.6% efficiency, 25-year warranty, excellent UK performance
- Best value: Longi Hi-MO 6, 22% efficiency at a lower price point, strong UK installer network
- Best premium: SunPower Maxeon 6, 22.8% efficiency, 40-year warranty, highest degradation resistance
- Best for small roofs: JA Solar DeepBlue 4.0, high output per m², 21.8% efficiency
- Most popular with UK installers: Trina Solar Vertex S+, reliable, well-priced, widely available
The short answer
For a UK roof, efficiency of 21% or better, a low degradation rate and a long performance warranty matter more than the headline wattage. The REC Alpha Pure-RX (22.6%, 25-year warranty) is the strongest all-rounder, the Longi Hi-MO 6 (22.0%) is the value pick, and the SunPower Maxeon 6 (22.8%, 40-year warranty) is the premium option.
Installed cost runs £1.20–£2.00 per watt. Orientation matters more than brand: a south-facing UK roof yields roughly 950–1,100 kWh per kWp a year whichever panel is on it.
What to look for in solar panels for UK homes
Choosing solar panels isn’t just about the highest efficiency number. UK conditions, cloud cover, shorter winter days, variable temperatures, mean certain specs matter more:
- Efficiency rating, percentage of sunlight converted to electricity. Look for 21%+ in 2026.
- Temperature coefficient, how much performance drops in heat. UK panels rarely overheat, but lower is better (closer to -0.30%/degC).
- Low-light performance, critical for UK. Some panels perform better on cloudy days.
- Warranty, product warranty (defects) and performance warranty (output guarantee). 12-25 years product, 25-30 years performance.
- Degradation rate, panels lose 0.25-0.55% output per year. Lower is better.
- Cost per watt, UK residential installs: £1.20-2.00/W installed.
Solar panel comparison table
| Panel | Efficiency | Wattage | Product Warranty | Perf. Warranty | Degradation | UK Cost (est.) |
|---|---|---|---|---|---|---|
| REC Alpha Pure-RX | 22.6% | 470W | 25 years | 25 years | 0.25%/yr | £180-220 |
| SunPower Maxeon 6 | 22.8% | 440W | 40 years | 40 years | 0.25%/yr | £250-320 |
| Longi Hi-MO 6 | 22.0% | 430W | 15 years | 25 years | 0.40%/yr | £120-160 |
| JA Solar DeepBlue 4.0 | 21.8% | 440W | 12 years | 30 years | 0.45%/yr | £110-150 |
| Trina Solar Vertex S+ | 21.5% | 435W | 15 years | 25 years | 0.40%/yr | £110-145 |
| Canadian Solar TOPHiKu6 | 21.5% | 440W | 12 years | 25 years | 0.45%/yr | £105-140 |
| Jinko Tiger Neo N-type | 22.3% | 445W | 15 years | 30 years | 0.40%/yr | £130-170 |
1. REC Alpha Pure-RX, Best overall
REC’s flagship uses heterojunction (HJT) technology, combining two cell types for superior efficiency. At 22.6% efficiency with 470W output, these panels deliver excellent power per square metre for typical UK roofs.
Why for UK homes: HJT cells give exceptional low-light performance, meaningful power even on overcast days. The 0.25%/yr degradation rate is among the lowest. A typical 4kW system uses 9-10 panels and costs £7,500-9,000 installed.
2. SunPower Maxeon 6, Best premium
SunPower’s Maxeon cells are the most tested in the industry, over 35 billion deployed with near-zero warranty claims. 22.8% efficiency backed by a 40-year warranty. The catch: 50-80% more per watt than mid-range options (£10,000-12,000 for a 4kW system).
Consider this
At current UK prices, the efficiency difference between SunPower (22.8%) and Longi (22.0%) translates to roughly £15-25/year extra generation, £375-625 over 25 years. Significant but unlikely to offset the £2,000-4,000 price premium.
3. Longi Hi-MO 6, Best value
Longi is the world’s largest solar manufacturer. The Hi-MO 6 offers the strongest price-to-performance ratio on the UK market at £120-160 per panel with 22% efficiency. Stocked by virtually every MCS-certified installer.
4. JA Solar DeepBlue 4.0, Best for small roofs
440W at 21.8% efficiency means more watts per square metre. A 4kW system needs ~9 panels (15.3m²) vs 10 panels (17m²) with lower-wattage alternatives. That difference can be the gap between fitting a system and not.
5. Trina Solar Vertex S+, Most popular
Not the most efficient or cheapest, but the most commonly installed panel in the UK. More UK installations use Trina than any other brand. Reliable, well-priced, and performs consistently.
How many panels do you need?
| System Size | Panels (430W) | Roof Space | Annual Generation | Est. Cost |
|---|---|---|---|---|
| 3kW | 7 panels | 12m² | 2,550 kWh | £5,500-7,000 |
| 4kW | 9-10 panels | 15-17m² | 3,400 kWh | £7,000-9,000 |
| 6kW | 14 panels | 24m² | 5,100 kWh | £9,500-12,000 |
Grants and financial support
As of April 2026, there is no direct government grant for solar panels for most UK homeowners. However:
- 0% VAT. Solar panels and installation are zero-rated until March 2027, saving 20%
- Smart Export Guarantee (SEG), Energy suppliers pay you for excess electricity (1p-15p/kWh)
- ECO4, Lower-income households may qualify for fully-funded solar panels. Check eligibility
Frequently asked questions
Are solar panels worth it in the UK?
Yes, for most homes. A typical 4kW system saves £500-800/year and pays for itself in 8-12 years. With 25+ year lifespans, you’ll generate significant savings.
Do solar panels work on cloudy days?
Yes, at 10-25% of peak capacity on heavily overcast days. Modern panels (REC, SunPower with HJT cells) perform better in low-light. UK homes still generate 70-85% of what panels produce in sunnier countries.
Which direction should my roof face?
South-facing is best. East/west still work well (80-85% of south output). North-facing generally not recommended. Read our full solar guide.
How long do solar panels last?
Most panels have 25-30 year performance warranties but last 30-40 years. After 25 years, quality panels produce 85-94% of original output. The inverter typically needs replacing after 10-15 years (£800-1,500).
Can I get a battery with my solar panels?
Yes. A 5kWh battery costs £2,500-4,000 installed. Read our battery storage guide.