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Solar Panel Guide
How Solar Sizing Works
Solar panels are rated in watts (W). A 400W panel produces 400 watts under standard test conditions (STC: 1,000 W/m2 irradiance, 25°C cell temperature). Real-world production depends on peak sun hours, system losses, tilt angle, and shading.
Peak Sun Hours (PSH)
PSH is the equivalent hours per day of full 1,000 W/m2 irradiance. The Caribbean averages 4.7–5.8 PSH, significantly higher than temperate regions (UK: 3.0). Higher PSH means fewer panels needed for the same energy production.
Panel Wattage Comparison
Type
Efficiency
Best For
330W
18.0%
Budget installs
400W
20.0%
Standard residential
450W
20.5%
Mid-range
500W
21.0%
High-performance
550W
22.0%
Premium / commercial
System Losses (Typical 14%)
• Inverter efficiency: 3–5%
• Wiring/connection losses: 2–3%
• Soiling (dust/dirt): 2–5%
• Temperature derating: 2–5% (significant in Caribbean heat)
• Module mismatch: 1–2%
Tilt Angle
Optimal tilt equals your latitude. Caribbean locations (10–25°N) benefit from 10–20° tilt. A 15° tilt is optimal for most Caribbean installations. Flat (0°) roofs lose ~13% production but simplify installation.
Caribbean Electricity Rates
Caribbean electricity is among the most expensive globally due to imported fossil fuel dependence. Jamaica's effective rate is ~J$62/kWh (including fuel surcharge). This high cost makes solar especially attractive with payback periods of 4–7 years.
Disclaimer: This calculator provides estimates for preliminary sizing. Actual production depends on site-specific conditions including exact location, roof orientation, local weather patterns, and equipment specifications. Always consult a qualified solar installer for detailed system design and permitting.
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