Solar Harvest Calculations
Solar Harvest Calculations
Learn to estimate how much energy your panels will produce each day and month.
8 min read
Simple and practical
Beginner level
No solar background needed
PH context
Made for local homes
What you will understand
Visual Learning Map
Lesson Guide
Harvest Formula
Daily kWh = Panels × Wattage × Peak Sun Hours × Efficiency ÷ 1000
Monthly kWh = Daily kWh × 30
Regional Peak Sun Hours (PH)
| Region | Peak Sun Hours |
|---|---|
| Metro Manila | 4.5 |
| Cebu / Visayas | 5.0 |
| Davao / Mindanao | 5.2 |
| Baguio / North | 4.0 |
Example: 6 × 550W in Manila
Daily = 6 × 550 × 4.5 × 0.8 ÷ 1000 = 11.9 kWh/day Monthly = 11.9 × 30 = 357 kWh/month
At ₱12/kWh, that's ₱4,284/month in generation value!
Frequently Asked Questions
Why is my harvest lower than calculated?
Shading, dust, heat, wiring losses, and inverter clipping all reduce real output.
Best month for solar in PH?
March–May (summer) has highest output. June–October (rainy) is lowest.
How much does dust reduce output?
Dirty panels can lose 5–15%. Clean every 2–3 months or after dusty construction nearby.
Does temperature affect output?
Yes — panels lose ~0.4% efficiency per °C above 25°C. PH heat matters!
How do I track actual harvest?
Use your inverter app/monitor. Compare daily kWh against calculations to spot issues.
Common Mistakes to Avoid
Using peak sun hours for rainy season only
Use annual averages for sizing. Don't size based on best-month output.
Not monitoring after install
Track monthly. A sudden drop signals shading, fault, or dirty panels.
Expecting rated wattage all day
Panels hit rated power only briefly at solar noon. Daily total is what matters.