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Simulation Inputs

This comprehensive guide covers all inputs required for P90 uncertainty analysis, from weather data to system configuration and simulation settings.

P90 analysis requires three main categories of inputs:

  1. Weather Data - Meteorological time series data for your site
  2. System Configuration - Physical and electrical specifications of your PV system
  3. Simulation Settings - Parameters controlling the Monte Carlo analysis

Weather data provides the foundation for all yield calculations. P90 accepts weather data in multiple formats and handles missing values through fallback mechanisms.

PVW Files - SunSolve’s optimized weather format containing:

  • Solar position data (zenith angle, azimuth angle)
  • Meteorological variables (GHI, DHI, temperature, wind speed)
  • Optional time-step specific values (albedo, soiling, tilt angle)

CSV Files - Standard meteorological data files with required variables:

  • Timestamp information
  • Global Horizontal Irradiance (GHI)
  • Diffuse Horizontal Irradiance (DHI)
  • Ambient temperature
  • Wind speed

All weather data must include:

  • Solar Position: Zenith angle (0-180°), Azimuth angle (0-360°)
  • Irradiance: GHI (≥0 W/m²), DHI (≥0 W/m²)
  • Temperature: Ambient temperature (K)
  • Wind: Wind speed (≥0 m/s)

These can be included in weather files or will use fallback values:

  • Albedo (0-1): Ground reflectance
  • Soiling Front (0-1): Front surface soiling losses
  • Soiling Rear (0-1): Rear surface soiling losses
  • Tilt Angle (-90° to 90°): Module tilt for this time step
  • Rear Transmission Factor (≥0): Bifacial rear transmission
  • Rear Structural Shading Factor (0-1): Rear structural shading

When time-step specific values are not provided in weather data, P90 uses fallback values that you can configure. If you don’t specify fallback values, system defaults are used.

P90 uses a hierarchical approach to determine final values:

  1. Time-step data (highest priority): Values included in weather file
  2. User-specified fallbacks: Values you configure for missing time-step data
  3. System defaults: Built-in defaults used when no other value is available

This ensures robust analysis even with incomplete weather data while allowing full customization when detailed information is available.