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Suntech STPxxxS 550W: Veteran Reliability for 2025 SA C&I Solar

Founded in 2001, Suntech has over 20 GW installed globally. The STPxxxS series powers warehouses and factories across SA with proven long-term performance.

R2,800

Price per panel

21.3%

Efficiency

550 W

Power Output

4.6/5

SPG Rating

Brand Legacy & Market Leadership

Suntech was a pioneer in the solar industry, founded in 2001 and one of the first to reach 1 GW production. Today, they’re a Tier 1 manufacturer with:

20 GW+ Installed globally
REIPPPP Early project participant
Local Support JHB & CPT warehouses
25-Year Warranty Standard

Full Technical Specifications

Electrical Data (STC)

Maximum Power (Pmax): 550 W
Open Circuit Voltage (Voc): 49.8 V
Short Circuit Current (Isc): 13.95 A
Module Efficiency: 21.3%
Temperature Coefficient (Pmax): -0.35%/°C

Mechanical Data

Cell Type: 182 mm half-cut monocrystalline PERC
Dimensions: 2278 × 1134 × 35 mm
Weight: 28.5 kg
Glass: 3.2 mm tempered, anti-reflective
Frame: Anodized aluminum, high load

Real-World Performance in SA Commercial Installs

1,980

kWh/kWp (Joburg flat roof)

1,850

kWh/kWp (Cape Town)

96%

Bifacial gain (rear-side)

The STPxxxS excels in high-irradiance environments with low degradation and excellent temperature stability.

Return on Investment – 2025 SA C&I

System Size	Panels	Cost (Installed)	Annual Savings	Payback
55 kW	100 × 550W	R290,000	R65,000	4.5 years
110 kW	200 × 550W	R560,000	R130,000	4.3 years

*R1.80/kWh commercial tariff, 5% escalation, 1,900 kWh/kWp average.

Pros & Cons – Commercial Buyer View

Pros

Proven 20+ year track record
High power density (550W)
Excellent warranty & local support
Ideal for flat roof C&I

Cons

Heavier than residential panels
Not optimized for shaded areas

Final Verdict

4.6 / 5

The Suntech STPxxxS 550W is the trusted workhorse for South African commercial & industrial solar in 2025.

Perfect for warehouses, factories, and large flat roofs.