(solar_resource:models)=
# Solar Resource: Model Overview

- [GOES PSM v4 API](solar_resource:goes_v4_api): these models require an API key from the [NREL developer network](https://developer.nrel.gov/signup/), the available models are:
    - "GOESAggregatedSolarAPI"
    - "GOESConusSolarAPI"
    - "GOESFullDiscSolarAPI"
    - "GOESTMYSolarAPI"
- [Himawari PSM v4 API](solar_resource:himawari_v3_api): these models require an API key from the [NREL developer network](https://developer.nrel.gov/signup/), the available models are:
    - "Himawari7SolarAPI"
    - "Himawari8SolarAPI"
    - "HimawariTMYSolarAPI"
- [Meteosat Prime Meridian PSM v4 API](solar_resource:msg_v4_api): these models require an API key from the [NREL developer network](https://developer.nrel.gov/signup/), the available models are:
    - "MeteosatPrimeMeridianSolarAPI"
    - "MeteosatPrimeMeridianTMYSolarAPI"


```{note}
Please refer to the [`Setting Environment Variables`](environment_variables:setting-environment-variables) doc page for information on setting up an NREL API key if you haven't yet.
```

(solarresource:overview)=
# Solar Resource: Output Data

Solar resource models may output solar resource data, site information, information about the data source, and time information. This information is outputted as a dictionary. The following sections detail the naming convention for the dictionary keys, standardized units, and descriptions of all the output data that may be output from a solar resource model.

- [Solar Resource: Model Overview](#solar-resource-model-overview)
- [Solar Resource: Output Data](#solar-resource-output-data)
  - [Primary Data: Solar Resource Timeseries](#primary-data-solar-resource-timeseries)
  - [Additional Data: Site Information](#additional-data-site-information)
  - [Additional Data: Data source](#additional-data-data-source)
  - [Additional Data: Time profile](#additional-data-time-profile)


```{note}
Not all solar resource models will output all the data keys listed below. Please check the documentation for each solar resource model and solar performance model to ensure compatibility.
```

(primary-data-solar-resource-timeseries)=
## Primary Data: Solar Resource Timeseries
The below variables are outputted as arrays, with a length equal to the simulation duration. The naming convention and standardized units of solar resource variables are listed below:
- `wind_direction`: wind direction in degrees (units are 'deg')
- `wind_speed`: wind speed in meters per second (units are 'm/s')
- `temperature`: air temperature in Celsius (units are 'C')
- `pressure`: air pressure in millibar (units are 'mbar')
- `relative_humidity`: relative humidity represented as a percentage (units are 'percent')
- `ghi`: global horizontal irradiance in watts per square meter (units are 'W/m**2')
- `dni`: beam normal irradiance in watts per square meter (units are 'W/m**2')
- `dhi`: diffuse horizontal irradiance in watts per square meter (units are 'W/m**2')
- `clearsky_ghi`: global horizontal irradiance in clearsky conditions in watts per square meter (units are 'W/m**2')
- `clearsky_dni`: beam normal irradiance in clearsky conditions in watts per square meter (units are 'W/m**2')
- `clearsky_dhi`: diffuse horizontal irradiance in clearsky conditions in watts per square meter (units are 'W/m**2')
- `dew_point`:  dew point in Celsius (units are 'C')
- `surface_albedo`: surface albedo represented as a percentage (units are 'percent')
- `solar_zenith_angle`: solar zenith angle in degrees (units are 'deg')
- `snow_depth`: snow depth in centimeters (units are 'cm')
- `precipitable_water`: precipitable water in centimeters (units are 'cm')

(additional-data-site-information)=
## Additional Data: Site Information
- `site_id` (int): site identification
- `site_tz` (int | float): local timezone for the site
- `site_lat` (float): latitude of the site
- `site_lon` (float): longitude of the site
- `elevation` (float | int): elevation of the site in meters

(additional-data-data-source)=
## Additional Data: Data source
- `data_tz` (int | float): timezone the data is in represented as an hour offset from UTC
- `filepath` (str): filepath where the resource data was loaded from
- `start_time` (str): the start time of resource data formatted as "yyyy/mm/dd hh:mm:ss (tz)", where tz is the timezone represented as the UTC offset
- `end_time` (str): the end time of resource data formatted as "yyyy/mm/dd hh:mm:ss (tz)", where tz is the timezone represented as the UTC offset
- `dt` (int | float): the timestep of resource data in seconds

(additional-data-time-profile)=
## Additional Data: Time profile
Time data may be outputted as arrays to represent the time profile of the resource data. These times should be represented in the timezone of `data_tz` (if outputted).
- `year`: year as 4-digit value (i.e., 2019)
- `month`: month of year (1-12)
- `day`: day of month (1-31)
- `hour`: hour of day from a 24-hour clock (0-23)
- `minute`: minute of hour (0-59)