Solar Panels
Suntech STP400S-C54/Umhb All Black
Established Chinese tier-1 Mono PERC all-black panel. 400W, 21.0% efficiency.
£103.75 per panel
How it scores
Scores based on published manufacturer specifications and weighted criteria — not lab testing. Methodology.
Specifications
- Cell type
- Mono PERC
- Watt peak
- 400
- Weight kg
- 21
- Dimensions mm
- 1722x1134x30
- Efficiency %
- 21
- Degradation % years
- 0.55
- Warranty product years
- 12
- Warranty performance years
- 25
- Temperature coefficient %
- -0.35
What I noticed
Suntech is one of the oldest Chinese solar manufacturers, with global distribution since the 2000s. The STP400S-C54/Umhb is their current Mono PERC residential platform — 400W at 21.0% module efficiency in a 1722×1134mm all-black 54-cell format.
This is a conventional Mono PERC panel rather than current N-Type — efficiency and degradation rate are step behind the TOPCon and HJT panels in this comparison, but the cell technology is mature with extensive real-world track record.
Who it suits
Buyers who want an established global brand with strong distributor support, in the standard 54-cell residential format, without paying a premium for N-Type. The all-black aesthetic suits any roof type.
What I'd watch for
At £103.75 per panel for a 400W Mono PERC, the price is high relative to similar-spec competitors — equivalent panels from Sharp or Canadian Solar are significantly cheaper. Worth comparing total system cost across installers before committing. Suntech's UK installer presence is moderate; confirm your installer has experience.
STP400S-C54/Umhb All Black head-to-heads
Side-by-side scoring vs each alternative in our shortlist.
Other Solar Panels on my shortlist
Read next
Background reading and decision-tree pages that put this product in context.
Stage 5: Panels and batteries explained
TOPCon vs PERC, efficiency, degradation — the specs that actually matter.
TOPCon vs PERC solar panels 2026
N-type vs P-type: real performance gap and whether the premium pays off.
Solar panel cost UK 2026
What a full installation actually costs in 2026 — and what drives the price.
How many solar panels do I need?
Sizing based on your roof, usage, and whether you want a battery.