The "best solar panels" question gets different answers depending on who you ask. Panel manufacturers sponsor every comparison site. Here's our honest take as an installer who fits 400+ systems per year and has no financial incentive to push any particular panel brand.
What "Tier 1" actually means
Bloomberg NEF assigns Tier 1 status to manufacturers based on financing track record, not panel quality. Tier 1 means a bank will finance a project using those panels — it's a bankability rating, not a performance rating.
That said: all Tier 1 manufacturers make consistently good panels. The difference between the top 15 manufacturers is smaller than the difference between installers.
The panels we actually fit most
JA Solar (JAM72 series) — our volume workhorse. 395–430 W per panel, 25-year performance warranty, competitive pricing. Excellent consistency batch-to-batch. We fit these on ~40% of domestic installs.
Trina Solar (Vertex S+) — similar spec to JA, slightly better aesthetics with the black backsheet option. Popular with customers who want an all-black look. ~25% of our installs.
Longi Hi-Mo X6 — the premium domestic choice. TOPCon cell technology adds 3–5% more output per m² vs standard PERC. Worth it for installations where roof space is limited. ~15% of installs.
REC AlphaPure — the premium-premium option. Heterojunction (HJT) cells. Best efficiency available in the UK (22.6%). We fit these on smaller roofs that can't fit a full-size system at PERC efficiency. ~5% of installs.
Sunpower Maxeon — still excellent but premium pricing means we recommend REC as better value in the same tier. Available on request.
The efficiency numbers that matter
| Panel | Technology | Efficiency | Warranty | Our Rating | |---|---|---|---|---| | REC AlphaPure 430W | HJT | 22.6% | 25 yr | Premium — limited roof space | | Longi Hi-Mo X6 410W | TOPCon | 22.0% | 25 yr | Best mid-premium | | JA Solar JAM54D 415W | PERC | 21.5% | 25 yr | Best value | | Trina Vertex S+ 415W | PERC+ | 21.4% | 25 yr | Best aesthetics | | Sunpower Maxeon 6 440W | HJT | 22.8% | 40 yr | Expensive but exceptional |
What about Chinese panels with no UK brand recognition?
Generic panels from unknown manufacturers are typically £80–£120 cheaper per system. The problem: no UK distributor means no warranty enforcement. We've seen customers stuck with panels under warranty where the manufacturer has no UK entity to claim against. We don't fit unbranded panels.
Inverter choice matters more than panel choice
Counterintuitively, inverter quality has more impact on long-term performance than panel choice. The inverter is the part that fails — typically at year 12–15. Panel degradation curves are similar across Tier 1 manufacturers.
The right panel + wrong inverter combination routinely underperforms the right inverter + mid-tier panel. When comparing quotes, pay as much attention to the inverter spec as the panel brand.
Our recommendation
For most UK homes in 2026: - Best value: JA Solar 415 W + GivEnergy or SolarEdge inverter - Best mid-premium: Longi Hi-Mo X6 + SolarEdge HD-Wave - Limited roof space: REC AlphaPure + any hybrid inverter
What NOT to optimise for: aesthetics at the cost of efficiency. An all-black panel looks better but generates 2–3% less than a standard panel. Over 25 years that's meaningful.