1. Irradiance and Weather

Definition of irradiance and weather data for the performance model

2. Incident Irradiance

Transposition of irradiance into direct and diffuse components

Translation of irradiance to the Plane-of-Array (POA)

3. Shading, Soiling, and Reflection Losses

Evaluation of the loss of irradiance due to shading, soiling! And reflection losses

4. Cell Temperature

Calculation of cell temperature from irradiance, ambient air temperature and wind speed

5. Module Output

Calculation of the IV curve for the specific irradiance and temperature conditions

6. DC and Mismatch Losses

Accounting for losses in the DC array due to mismatch or wiring

7. DC to DC Max Power Point Tracking

Adjusting the DC voltage to maximize output power from the array

8. DC to AC Conversion

Representing conversion losses in the inverter

9. AC Losses

Representing AC losses before the utility meter

Modeling Steps Outline

• Irradiance and Weather
  • Definitions and Overview
  • Sun Position
    • Solar Position Algorithm (SPA)
    • Simple models
    • Sandia’s code
  • Irradiance and Insolation
    • Extraterrestrial radiation
    • Air Mass
    • Direct Normal Irradiance
      • DISC Model
      • DIRINT Model
    • Global Horizontal Irradiance
    • Diffuse Horizontal Irradiance
    • Spectral Content
      • AM 1.5 Standard Spectrum
    • Satellite derived data
  • Weather Observations
    • Air Temperature
    • Wind Speed and Direction
    • Precipitation
    • Air Pressure
  • Irradiance Data Sources for Performance Modeling
    • National Solar Radiation Database
    • Typical Meteorological Years
    • Site-Specific Data
    • Measure Correlate Predict
    • Irradiance Modeling
  • Uncertainty and Variability
    • Characterization of Irradiance Variability
      • Interannual variability
      • Short-term variability
      • Spatial variability
    • Clear Sky Irradiance models
• Incident Irradiance
  • Definitions and Overview
  • Array Orientation
    • Fixed tilt
    • Single Axis Tracking
      • 1-Axis Horizontal Roll
      • 1-Axis Tilted Roll
      • 1-Axis Equatorial
    • Two-Axis Tracking
      • 2-Axis Azimuth-Elevation
      • 2-Axis Polar
      • 2-Axis Tilt-Roll
    • Array Orientation Errors
      • Effect of Array Tilt Errors
      • Effect of Array Azimuth Errors
  • Plane of Array (POA) Irradiance
    • Measuring POA Irradiance
    • Calculating POA Irradiance
      • POA Beam
      • Angle of Incidence
      • POA Ground Reflected
        • Albedo
      • POA Sky Diffuse
        • Isotropic Sky Diffuse Model
        • Simple Sandia Sky Diffuse Model
        • Hay Sky Diffuse Model
        • Reindl Sky Diffuse Model
        • Perez Sky Diffuse Model
    • Concentrators
    • POA Irradiance Uncertainty and Validation
• Shading, Soiling, and Reflection Losses
  • Definitions and Overview
  • Shading
    • Far Shading
    • Near Shading
  • Soiling and Snow
    • Soil Monitoring Studies
    • Snow Effects
  • Incident Angle Reflection Losses
    • Physical Model of IAM
    • ASHRAE Model
    • Martin and Ruiz IAM Model
      • Soiling effects on Incident Angle Losses
    • Sandia Model
• Cell Temperature
  • Definitions and Overview
  • Module Temperature
    • Thermocouple
    • Voc method
    • Sandia Module Temperature Model
    • Faiman Module Temperature Model
  • Cell temperature
    • Sandia Cell Temperature Model
    • PVsyst Cell Temperature Model
    • Transient Cell Temperature Models
• Module IV Curve
  • Definitions and Overview
  • Effective Irradiance
    • Spectral Mismatch
  • Single Diode Equivalent Circuit Models
    • De Soto “Five-Parameter” Module Model
    • PVsyst Module Model
  • Point-value models
    • Sandia PV Array Performance Model
    • Loss Factor Model
    • PVWatts
      • Improvements to PVWatts
• DC and Mismatch Losses
  • Definitions and Overview
  • Module IV Curves
  • String IV Curves
    • String Mismatch Losses
  • Array IV Curves
    • Array Mismatch Losses
  • DC Wiring Losses
  • Uncertainty and Validation Studies
• Maximum Power Point Tracking
  • Definitions and Overview
  • Array Utilization
  • MPPT Voltage
  • MPPT Efficiency
  • MPPT Algorithms
  • Uncertainty and Validation
• DC to AC Conversion
  • Definitions and Overview
  • Inverter Efficiency
    • CEC Inverter Test Protocol
    • Operating Temperature
    • Sandia Inverter Model
    • Driesse Inverter Model
  • Inverter Saturation
  • Loss of Grid
  • Advanced Inverter Features
    • Power Factor Control
  • Uncertainty and Validation
• AC Losses
  • Definitions and Overview
  • AC Wiring Losses
  • Transformer Losses
• PV Systems Operations and Maintenance
  • Definitions and Overview
  • Availability
  • Failure Mode and Rates
• PV System Output
  • Definitions and Overview
  • PV System Monitoring
    • Monitoring Equipment
    • Data Filtering
    • Data Filling
  • PV Performance Metrics
    • Performance Ratio
    • Performance Index
    • Annual Yield
• References