JA Solar
JAM54S30
400W PERC panel from one of the world's largest manufacturers.
From £195 per panel installed
How it scores
Scores based on published manufacturer specifications and weighted criteria — not lab testing. Methodology.
Specifications
- Watt peak
- 400
- Weight kg
- 21.3
- Dimensions mm
- 1722x1134x30
- Efficiency %
- 20.4
- Cell technology
- PERC
- Degradation yr1 %
- 2
- Degradation annual %
- 0.55
- Warranty years product
- 12
- Warranty years performance
- 25
- Temperature coefficient %
- -0.35
What I noticed
JA Solar is the second-largest solar panel manufacturer in the world and the JAM54S30 is the kind of panel that ends up on a significant proportion of UK residential installs — reliable, well-priced, and backed by a company with the scale to honour long-term warranties. At 400W and 20.4% efficiency, it is not the most impressive panel on paper, but the economics are hard to argue with at £195 per panel.
The 12-year product warranty is shorter than Canadian Solar's 15 years, which is worth noting. The 25-year performance warranty is standard. Degradation is 2% in year one and 0.55%/year after — identical to the Canadian Solar HiKu7 — leaving around 86% of original output at year 25.
Who it suits
Installers and homeowners prioritising cost per watt on large roof areas. If you have a 50m² south-facing roof and want to maximise generation within a fixed budget, the JA Solar panel lets you fit more panels for the same spend. The manufacturing quality is consistently good at this price point — JA Solar's products go through the same third-party certification processes as premium brands.
What I'd watch for
The 12-year product warranty is the weakest in this comparison. JA Solar as a company is not going anywhere — they're too large — but the shorter warranty period is a data point worth factoring in. If the physical panel develops a defect between year 12 and year 25, you are outside warranty coverage. For many homeowners that risk is acceptable given the price difference; it is simply worth knowing. Also note that JA Solar produces many variants — confirm the exact model number with your installer.