| Timestamp | yyyy-MM-dd HH:mm:ss | Date and time for the calculation timestep |
| Sun Zenith Angle | ° | Angle between the sun and the vertical (zenith), where 0° is directly overhead and 90° is at the horizon |
| Sun Azimuth Angle | ° | Compass direction of the sun measured clockwise from north |
| Tracker Angle | ° | Current rotation angle of the tracker, applicable for single-axis tracking systems |
| Module Tilt Angle | ° | Angle of the module surface relative to horizontal, accounting for tracker position if applicable |
| Module Azimuth Angle | ° | Compass direction the module surface faces, measured clockwise from north |
| Incidence Angle | ° | Angle between the sun’s direct beam and the normal to the module surface |
| Beam POAI | W/m² | Direct beam component of plane-of-array irradiance before any corrections or losses |
| Diffuse POAI | W/m² | Diffuse sky component of plane-of-array irradiance before any corrections or losses |
| Ground POAI | W/m² | Ground-reflected component of plane-of-array irradiance before any corrections or losses |
| Global POAI | W/m² | Total plane-of-array irradiance (beam + diffuse + ground) before any corrections or losses |
| 3D Corrected Beam POAI | W/m² | Direct beam POAI after applying 3D transposition correction factors |
| 3D Corrected Diffuse Sky POAI | W/m² | Diffuse sky POAI after applying 3D transposition correction factors |
| 3D Corrected Ground POAI | W/m² | Ground-reflected POAI after applying 3D transposition correction factors |
| 3D Corrected Global POAI | W/m² | Total POAI after applying 3D transposition correction factors, sum of 3D corrected components |
| Horizon Shaded Beam POAI | W/m² | Direct beam POAI after applying horizon shading losses |
| Horizon Shaded Diffuse POAI | W/m² | Diffuse sky POAI after applying horizon shading losses |
| Horizon Shaded Ground POAI | W/m² | Ground-reflected POAI after applying horizon shading losses |
| Horizon Shaded Global POAI | W/m² | Total POAI after horizon shading, sum of horizon-shaded components |
| Near Shaded Beam POAI | W/m² | Direct beam POAI after applying near (inter-row) shading losses |
| Near Shaded Diffuse POAI | W/m² | Diffuse sky POAI after applying near shading losses |
| Near Shaded Ground POAI | W/m² | Ground-reflected POAI after applying near shading losses |
| Near Shaded Global POAI | W/m² | Total POAI after near shading, sum of near-shaded components |
| Beam POAI After Soiling | W/m² | Direct beam POAI after applying soiling losses |
| Diffuse POAI After Soiling | W/m² | Diffuse sky POAI after applying soiling losses |
| Ground POAI After Soiling | W/m² | Ground-reflected POAI after applying soiling losses |
| Global POAI After Soiling | W/m² | Total POAI after soiling losses, sum of soiled components |
| Beam POAI After IAM | W/m² | Direct beam POAI after applying incidence angle modifier losses |
| Diffuse POAI After IAM | W/m² | Diffuse sky POAI after applying incidence angle modifier losses |
| Ground POAI After IAM | W/m² | Ground-reflected POAI after applying incidence angle modifier losses |
| Global POAI After IAM | W/m² | Total POAI after IAM losses, sum of IAM-corrected components |
| Beam IAM Factor | % | Incidence angle modifier factor for direct beam irradiance |
| Diffuse IAM Factor | % | Incidence angle modifier factor for diffuse irradiance |
| Ground IAM Factor | % | Incidence angle modifier factor for ground-reflected irradiance |
| Effective Beam POAI | W/m² | Final effective direct beam POAI after all irradiance losses including spectral correction |
| Effective Diffuse POAI | W/m² | Final effective diffuse sky POAI after all irradiance losses including spectral correction |
| Effective Ground POAI | W/m² | Final effective ground-reflected POAI after all irradiance losses including spectral correction |
| Effective Global POAI | W/m² | Final effective total POAI used for DC power calculation, sum of effective components |
| Global Tilted Direct Beam Irradiance w/ Electrical Shading | W/m² | Direct beam POAI with electrical shading factor applied, used for electrical mismatch calculations |
| Beam Shading Factor | — | Fraction of direct beam irradiance remaining after geometric shading (1.0 = no shading) |
| Diffuse Shading Factor | — | Fraction of diffuse irradiance remaining after geometric shading |
| Ground Shading Factor | — | Fraction of ground-reflected irradiance remaining after geometric shading |
| Beam Electrical Shading Factor | — | Fraction of direct beam irradiance remaining after electrical shading effects |
| DC Power at STC | W | Aggregate DC power output of the DC field calculated at standard test conditions (1000 W/m², 25°C cell temperature) |
| DC Power at 25C | W | DC field power output at actual irradiance but with cell temperature fixed at 25°C, used to isolate temperature effects |
| Module Irradiance | W | Total irradiance power incident on module area, calculated as effective global POAI multiplied by module area |
| DC Power Lost due to Electrical Shading | W | Power loss attributed to electrical mismatch from partial shading conditions |
| DC Power Lost due to Module Quality | W | Power loss from module quality/binning deviation from nameplate specifications |
| DC Power Lost due to LID | W | Power loss from light-induced degradation effects |
| DC Power Lost due to Module Mismatch | W | Power loss from electrical mismatch between modules in the DC field |
| Backside Irradiance | W | Total irradiance incident on the rear side of bifacial modules |
| Structure Shading Loss | W | Power loss from mounting structure shading on the rear of bifacial modules |
| DC Power Lost due to DC Health | % | Percentage power loss applied to account for DC system health factors |
| Ohmic Power Loss | W | Resistive power losses in DC wiring between modules and inverter input |
| Cell Temperature at MPP | °C | Module cell temperature calculated for maximum power point operating conditions |
| Cell Temperature at Open Circuit | °C | Module cell temperature calculated for open circuit voltage conditions |
| Module Surface Temperature | °C | Temperature of the module back surface |
| Open Circuit DC Voltage at MPP Cell Temperature | V | DC field open circuit voltage calculated using cell temperature at MPP conditions |
| Open Circuit DC Voltage at Open Circuit Cell Temperature | V | DC field open circuit voltage calculated using cell temperature at open circuit conditions |
| DC Voltage at MPP | V | DC field voltage at the maximum power point before inverter limitations |
| Short Circuit Current | A | DC field short circuit current at operating conditions |
| 3hr Rolling Avg DC String Short Circuit Current | A | Three-hour rolling average of DC string short circuit current, used for fuse sizing validation |
| DC Current at MPP | A | DC field current at the maximum power point before inverter limitations |
| DC Power at MPP | W | DC field power at the maximum power point before inverter limitations |
| DC Voltage | V | Final DC field operating voltage after inverter operating point adjustment |
| DC Current | A | Final DC field operating current after inverter operating point adjustment |
| DC Power | W | Final DC power delivered to the inverter input, calculated as DC Voltage × DC Current |
| Spectral Shift Factor | — | Spectral correction factor applied to account for atmospheric spectral variations from reference spectrum |
| Global Back POAI | W/m² | Total plane-of-array irradiance on the rear side of bifacial modules |
| Ave Ground GHI | W/m² | Average global horizontal irradiance on the ground beneath the array, used in bifacial calculations |
| Effective Global Back POAI | W/m² | Final effective rear-side POAI after all losses, used for bifacial power contribution |
| Effective Back POAI Lost due to BiFaciality | W/m² | Rear-side POAI reduction from bifaciality factor application |
| DC Power Lost due to Back Mismatch | W | Power loss from rear-side irradiance mismatch in bifacial modules |
