Solar Resource

High-irradiance regions: Up to 1,600–1,800 hours, with high theoretical electricity generation.

Medium-irradiance regions: Approximately 1,200–1,400 hours, yielding moderate electricity generation.

Low-irradiance regions: Potentially below 1,000 hours, with comparatively low electricity generation.

Installation Conditions

Orientation: South-facing is optimal, with east-west orientations reducing power generation by approximately 15%-20%.

Tilt angle: Efficiency peaks when aligned with the local latitude.

Shading: Obstructions from surrounding buildings or trees may cause power generation losses of 10%-30%.

Equipment Efficiency

Solar Panels: Monocrystalline silicon efficiency (20%-22%), polycrystalline silicon (17%-19%); high-efficiency modules can increase power generation by 5%-10%.

Inverters: Conversion efficiency ranges from 97% to 99%; inefficient products may incur losses of 2% to 3%.

System overall efficiency: Typically 75%-85% (accounting for temperature, dust, line losses, etc.).

Calculation Method

Annual electricity generation (kWh) = Installed capacity (kW) × Peak sunshine hours (h) × System efficiency

High Irradiation Region:

1000 kW × 1600 h × 0.8 = 1,280,000 kWh

Actual output may reach 1.3 -1.5 million kilowatt-hours (high-efficiency modules + low-loss design)

Medium Irradiation Region:

1000 kW × 1300 h × 0.8 = 1,040,000 kWh

Actual generation is approximately 900,000-1,200,000 kWh (considering optimized roof tilt angles).

Low Irradiation Region:

1000 kW × 1000 h × 0.75 = 750,000 kWh

Actual generation may fall below 800,000 kWh (due to rainy, cloudy weather).

 Actual Generation Efficiency

In practice, solar panels often fail to meet standard testing conditions, with an allowable deviation in output of 5%. Therefore, when analysing solar panel output power, the impact factor of 0.95 must be taken into account.

Actual power generation efficiency = Theoretical annual power generation * Actual power generation efficiency (0.95)