Measure daylight across seasons, clouds, and shade. Review usable sun hours, solar window, and losses. Make better roof and panel planning decisions every day.
Use this sample to understand how the calculator handles site losses and sunlight quality adjustments.
| Site | Sunrise | Sunset | Peak Sun Hours | Cloud % | Shade % | Tilt % | Season % | Weather % | Surface % |
|---|---|---|---|---|---|---|---|---|---|
| Urban Roof A | 06:10 | 17:50 | 5.60 | 18 | 10 | 100 | 96 | 95 | 7 |
| Farm Shed B | 05:55 | 18:05 | 6.20 | 12 | 6 | 103 | 101 | 98 | 5 |
| Valley Home C | 06:20 | 17:25 | 4.80 | 30 | 22 | 95 | 90 | 92 | 9 |
Daylight Hours = Sunset Time - Sunrise Time
Cloud Factor = 1 - (Cloud Cover / 100)
Shade Factor = 1 - (Shading Loss / 100)
Surface Factor = 1 - (Surface Loss / 100)
Usable Sunlight = Daylight × Cloud Factor × Shade Factor × Surface Factor × Tilt Factor × Seasonal Factor × Weather Factor
Availability % = (Usable Sunlight / Daylight Hours) × 100
Effective Peak Sun Hours = Peak Sun Hours × All Adjustment Factors
This approach combines daylight length with local losses and performance multipliers, giving a practical estimate of how much sunlight remains useful for solar planning.
Enter the site name, sunrise time, and sunset time first. Add peak sun hours from your local solar map or historical monitoring source.
Next, estimate average cloud cover, shading loss, and dust loss. Then enter tilt, seasonal, and weather factors as percentages relative to expected performance.
Submit the form to see daylight duration, usable sunlight, availability percentage, effective peak sun hours, and a site rating above the form.
It estimates how much daylight remains useful for solar production after cloud cover, shade, site losses, tilt effects, and seasonal adjustments reduce ideal conditions.
No. Peak sun hours measure energy-equivalent full sunlight, while sunlight availability in this tool also reflects daylight length and loss conditions.
Use site observations, shade studies, drone reviews, or solar path tools. Include trees, walls, parapets, poles, and nearby buildings that block sunlight.
Use 100% for a neutral assumption. Enter above 100% for optimized tilt or below 100% when panel angle reduces expected sunlight capture.
Dust, pollen, soot, and surface grime reduce usable sunlight reaching the cells. Including them creates a more realistic planning result.
Yes. Monthly or seasonal averages work well for planning. Keep the factors consistent so you can compare roofs, months, or design options fairly.
Not always. Better sunlight helps, but savings also depend on system size, tariffs, inverter efficiency, battery use, and household demand timing.
Use it for screening and comparison. Final project decisions should also include irradiance records, structural review, electrical design, and installer validation.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.