Solar Energy Potential Estimator
Estimate annual solar energy generation based on roof area, location latitude, and panel efficiency. Includes tilt loss factors and shading coefficients.
About
Determining the feasibility of a Photovoltaic (PV) system requires analyzing the intersection of geographical potential and physical constraints. This estimator calculates the theoretical annual energy yield of a residential solar array. Unlike simple multipliers, this tool accounts for the system's Performance Ratio (PR), which includes losses from inverter inefficiency, wiring resistance, and temperature degradation.
Accuracy in this calculation is critical for financial forecasting. Overestimating generation leads to poor Return on Investment (ROI) models, while underestimating leads to oversized, expensive systems. This tool applies standard derating factors to provide a realistic engineering estimate of kWh production.
Formulas
The core formula for Annual Energy Generation (E) is:
Where:
- A = Total Solar Panel Area (m2)
- r = Solar Panel Efficiency (%)
- H = Annual Average Solar Radiation on tilted panels (kWh/m2)
- PR = Performance Ratio (coefficient)
Reference Data
| Variable | Typical Value | Description |
|---|---|---|
| Global Horizontal Irradiance (GHI) | 3 − 6 kWh/m²/day | The total solar radiation received on a horizontal surface. |
| Panel Efficiency (η) | 17% − 22% | The percentage of sunlight energy converted to electricity. |
| Performance Ratio (PR) | 0.75 − 0.85 | Coefficient accounting for system losses (thermal, cables, inverter). |
| Shading Loss | 0% − 20% | Reduction in yield due to trees, chimneys, or adjacent buildings. |
| Tilt Orientation Factor | 0.85 − 1.00 | Efficiency reduction if panels do not face true Equator (South/North). |
| Temperature Coefficient | -0.4% / °C | Efficiency loss for every degree above STC (25°C). |