Data Parameter Definitions

Basic plant parameters
Name Definition How we use this Unit Valid range Defaults
Name The user-defined name of the site Used to display a name for your site. Can be changed N/A N/A None - Required field
Latitude (site centre) Site latitude (centre of site) in decimal degrees (EPSG:4326). Used to locate your site. Cannot be changed ° -90 to +90 None - Required field
Longitude (site centre) Site longitude (centre of site) in decimal degrees (EPSG:4326). Used to locate your site. Cannot be changed ° -180 to +180 None - Required field
Tracking type The type of sun-tracking or geometrical configuration of your site's modules Used to calculate the incident irradiance for your modules N/A "fixed_tilt" or "horizontal_single_axis" None - Required field
Install date The date when your site was installed Used to derate your module (DC) production gradually with age, at a rate dependent on your Module Type date 1970-01-01 to present date Default: 1 year before date at site creation
AC capacity (inverters) in MW Total inverter (nameplate) capacity in MW. This is the highest potential output of the system before any Site Export Limit is applied Used to model the conversion of DC power to AC by your inverters MW >=0 None โ€“ Required field
DC capacity (modules) in MW Total module capacity in MW. Usually slightly higher than the AC capacity. Used to model the generation of DC power by your modules MW >=0 Default: 1.27*AC capacity
Grid export limit in MW The maximum power export limit in MW that is allowed by the site's connection with the network operator Used to place a final cap on your AC power output. Only impacts your AC power if the grid export limit is set lower than the AC capacity MW >=0 Default: Disabled
Module and inverter parameters
Name Definition How we use this Unit Valid range Defaults
Module type The type of material or technology used in your site's PV modules. Used to estimate your module temperature derating coefficient (unless you specify your own coefficient) and used to estimate your module age derating N/A Monocrystalline Silicon (mono-Si) Polycrystalline Silicon (poly-Si) Amorphous Silicon (a-Si) Cadmium Telluride (CdTe) Copper Indium Gallium Selenide (CIGS) Defaults:
Polycrystalline Silicon (poly-Si) if install date is >= 2013
Monocrystalline Silicon (mono-Si) if install date < 2013
Ground coverage ratio The proportion of the site's ground area covered by modules. Used to calculate the incident irradiance for your modules fraction 0 to 1 Defaults:
0.36 if tracking_type is horizontal_single_axis
0.47 if tracking type is fixed
Module temperature derating coefficient The factor by which your site's module (DC) production will be derated with increasing temperature Used to derate your module (DC) production gradually with increasing temperature K-1 -1 to 0 Defaults:
0.0039 (mono-Si)
0.0039 (poly-Si)
0.0031 (a-Si)
0.0026 (CdTe)
0.0042 (CIGS)
Peak inverter efficiency The peak efficiency value in your inverter efficiency curve Used to scale the conversion efficiency of DC to AC, as a function of the inverter load fraction 0 to 1 Defaults:
0.985
Age degradation derating coefficient The factor by which the whole system will be derated per year since the Install Date Used to calculate time dependent system los year-1 0 to 1 Defaults:
0.0023 (mono-Si)
0.0059 (poly-Si)
0.0095 (a-Si)
0.0030 (CdTe)
0.0002 (CIGS)
Other losses derating coefficient The factor by which the whole system will be derated due to causes other than temperature and degradation Used to calculate other system losses including mismatch, wiring and connection fraction 0 to 1 Defaults:
Inferred from AC capacity if not specified
Geometry parameters for fixed tilt sites
Name Definition How we use this Unit Valid range Defaults
Module tilt angle The off-horizontal tilt angle of modules for a fixed-tilt site. Used to calculate the incident irradiance for your modules ° 0 to 90. Zero means the modules are horizontal Default:
Quadratic function of site Latitude
Module azimuth angle The off-north-facing direction on the horizon in which the modules are facing for a fixed-tilt site. Used to calculate the incident irradiance for your modules ° -180 to 180. South is -180, East is -90, North is 0, West is 90 Default:
Set to 0 if latitude is less than zero, otherwise set to 180
Geometry parameters for horizontal single axis tracking sites
Name Definition How we use this Unit Valid range Defaults
Tracker axis azimuth angle The off north-south azimuth angle for a horizontal single axis tracking site. Most commonly this will be close to zero Used to calculate the incident irradiance for your modules ° -180 to 180. South is -180, East is -90, North is 0, West is 90 Default:
0 (north-south axis)
Tracker maximum rotation angle The maximum off-horizontal angle for a horizontal single axis tracking site. Used to calculate the incident irradiance for your modules ° 0 to 90 Default:
50 °
Tracker back-tracking Whether the trackers backtrack at low solar elevation angles, for a horizontal single axis tracking site. Used to calculate the incident irradiance for your modules boolean True, False Default:
True if install date is >Jan 2015, else false
Tracker smart tracking Whether the trackers move to horizontal during cloudy periods with zero DNI, for a horizontal single axis tracking site. Used to calculate the incident irradiance for your modules boolean True, False Default:
False
Site terrain and dust soiling parameters
Name Definition How we use this Unit Valid range Defaults
Average terrain slope The average terrain slope in degrees of your site. A site with no terrain slope has a value of zero. Used to calculate the incident irradiance for your modules ° 0 to 90 Default:
Average terrain azimuth The average terrain slope downhill direction. Used to calculate the incident irradiance for your modules. Terrain Azimuth is meaningful only when terrain_slope>0. ° -180 to 180. South is -180, East is -90, North is 0, West is 90. Default:
Average dust soiling losses The average proportion of module production lost due to dust soiling, from 0 to 1. E.g. 0.02 for April means a 2% soiling loss will be applied throughout April. The value entered should reflect the impact of cleaning activity at your site. Used to calculate the module (DC) production We accept either a single yearly average value, or a set of 12 monthly average values. fraction 0 to 1 Default:
0.015
Topographic horizon elevation The elevation angle of topography (e.g. hills and mountains) surrounding the general area of your site, at a set of specified different azimuth (direction) angles. Used to calculate the incident irradiance for your modules ° 0 to 90 for each elevation value. -180 to 180 for each azimuth value. The list must have the same number of azimuths and elevations Default:
0° elevation at every azimuth

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