Enter Solar System Inputs
The page stays in a single-column flow, while the form uses a responsive grid: three columns on large screens, two on smaller screens, and one on mobile.
Example Data Table
| Item | Example Value |
|---|---|
| Panel Wattage | 550 W |
| Number of Panels | 12 |
| Array DC Size | 6.60 kW |
| Peak Sun Hours | 5.5 hours |
| Irradiance | 850 W/m² |
| Daily AC Energy | 21.71 kWh/day |
| Monthly Energy | 651.37 kWh |
| Annual Energy | 7,925.06 kWh |
| Performance Ratio | 59.81% |
| Annual Value | $1,109.51 |
This example uses the default values already preloaded in the calculator form.
Formula Used
DC Size (kW) = Panel Wattage × Number of Panels ÷ 1000
Cell Temperature = Ambient Temperature + ((NOCT − 20) ÷ 800) × Irradiance
Temperature Factor = 1 + (Temperature Coefficient ÷ 100) × (Cell Temperature − 25)
Loss Factor = (1 − Shading) × (1 − Soiling) × (1 − Other Losses) × Availability × (1 − Degradation)
Daily AC Energy = DC Size × Peak Sun Hours × (Irradiance ÷ 1000) × Orientation Factor × Temperature Factor × Loss Factor × Inverter Efficiency
Specific Yield = Annual Energy ÷ DC Size
Performance Ratio = ((Daily AC Energy ÷ DC Size) ÷ Peak Sun Hours) × 100
Capacity Factor = Annual Energy ÷ (Nominal AC Size × 8760) × 100
This model is ideal for planning-level estimates. It does not simulate hourly clipping, spectral effects, battery charging behavior, or seasonal shading geometry.
How to Use This Calculator
- Enter module wattage and the number of panels to define total DC size.
- Add local peak sun hours and the expected irradiance on the panel plane.
- Provide ambient temperature, NOCT, and module temperature coefficient.
- Enter inverter efficiency, tilt/orientation factor, and all major loss assumptions.
- Set availability, annual degradation, and the period length you want to study.
- Optionally add energy price and grid emission factor for economic and carbon outputs.
- Click the calculation button to show the result above the form.
- Use the CSV or PDF buttons to export the calculated metrics.
Frequently Asked Questions
1) What does this calculator estimate?
It estimates solar PV energy output using module size, sun hours, irradiance, temperature, inverter efficiency, and real-world derating inputs. It also reports performance ratio, capacity factor, annual value, and carbon offset.
2) Why is irradiance separate from peak sun hours?
Peak sun hours represent equivalent solar energy duration, while irradiance adjusts how strong the sunlight is versus standard test conditions. Using both gives a more flexible engineering estimate.
3) What is the temperature coefficient?
It shows how much module power changes for each degree away from 25°C. Most crystalline modules have a negative value, meaning hotter cells usually reduce output.
4) What does the orientation factor represent?
It captures tilt and azimuth effects as a performance multiplier. A value below 100% reflects less-than-optimal positioning, while values near 100% indicate strong alignment with solar exposure.
5) Why include degradation in the estimate?
Degradation represents long-term module aging. Including it helps translate fresh nameplate performance into a more realistic annual production estimate for planning, budgeting, and lifecycle comparisons.
6) Is this calculator suitable for final project design?
It is excellent for feasibility studies, budget planning, and quick engineering comparisons. Final designs should still use detailed site surveys, shading analysis, hourly weather files, and equipment-specific simulation software.
7) What is performance ratio?
Performance ratio compares actual delivered energy against the ideal output expected from installed DC capacity and solar resource. It is a widely used indicator of overall PV system quality.
8) What do the CSV and PDF buttons export?
They export the calculated result metrics shown in the table above the form. CSV is convenient for spreadsheets, while PDF is useful for sharing reports and client summaries.