## Solar Irradiance History Forecast Bulk ### Product concept Solar Irradiance History Forecast Bulk is an one-off export of previously made solar irradiance forecasts for any coordinates on the globe. The archive contains a 16-day solar irradiance forecast with a 1-hour step for each day starting from April 2017 (a 15-minute forecast step is available by request). Please find detailed description in the ["Product structure"](#structure) and ["Fields in Solar Irradiance History Forecast Bulk"](#fields) sections. ## Product structure Solar Irradiance History Forecast Bulk provides a CSV archive of previously made 16 days ahead forecasts on solar irradiance data. The dataset for each day includes 4 kits of historical solar irradiance forecasts on 16 days ahead both for [clear sky](/api/solar-radiation/behind-solar-radiation-api.md#clearsky) and [cloudy sky](/api/solar-radiation/behind-solar-radiation-api.md#cloudysky) models with 1 hour step made on this specified date. Solar Irradiance forecast is generated 4 time per day at these times: 00:00 UTC, 06:00 UTC, 12:00 UTC, 18:00 UTC. Historical solar irradiance forecasts are avaiable starting from April 2017. It means that for each day, starting from April 2017, you will have four 16-day forecasts. Thus, each day has the following structure: ```text 00:00 UTC {forecast solar irradiance for 1st day - 16th day} 06:00 UTC {forecast solar irradiance for 1st day - 16th day} 12:00 UTC {forecast solar irradiance for 1st day - 16th day} 18:00 UTC {forecast solar irradiance for 1st day - 16th day} ``` The example of data can be found in the ["Sample data and examples"](#sample_and_response) section. The detailed information about what technologies, algorithms, etc. are behind the Solar Irradiance History Forecast Bulk can be founded [here](/api/solar-radiation/behind-solar-radiation-api.md). ## How to get Solar Irradiance History Forecast Bulk To request Solar Irradiance History Forecast Bulk for your locations, please [contact us](mailto:info@openweathermap.org) via email. We’ll prepare and export the data for you. ## Fields in Solar Irradiance History Forecast Bulk - `forecast_dt` Forecast calculation time in Unix timestamp - `forecast_dt_iso` Forecast calculation time in ISO format - `slice_dt` Time for which the corresponding forecast part was calculated in Unix timestamp - `slice_dt_iso` Time for which the corresponding forecast part was calculated in ISO format - `lat` Latitude of the location,decimal (-90; 90) - `lon` Longitude of the location,decimal (-180; 180) - `ghi_cloudy_sky` Cloudy sky GHI - [Global Horizontal Irradiance](/api/solar-radiation/behind-solar-radiation-api.md#introduction), W/m2 - `dni_cloudy_sky` Cloudy sky DNI - [Direct Normal Irradiance](/api/solar-radiation/behind-solar-radiation-api.md#introduction), W/m2 - `dhi_cloudy_sky` Cloudy sky DHI - [Diffuse Horizontal Irradiance](/api/solar-radiation/behind-solar-radiation-api.md#introduction), W/m2 - `ghi_clear_sky` Clear sky GHI - [Global Horizontal Irradiance](/api/solar-radiation/behind-solar-radiation-api.md#introduction), W/m2 - `dni_clear_sky` Clear sky DNI - [Direct Normal Irradiance](/api/solar-radiation/behind-solar-radiation-api.md#introduction), W/m2 - `dhi_clear_sky` Clear sky DHI - [Diffuse Horizontal Irradiance](/api/solar-radiation/behind-solar-radiation-api.md#introduction), W/m2 > For Solar Irradiance bulk we can provide you with a customized set and fields order in the API response. Please [contact us](mailto:info@openweathermap.org) via email and specify your needs. ## Sample data and example Here you can find and download example of Solar Irradiance History Forecast bulk file in CSV format. You can download sample of files History Forecast bulk in CSV format using link below: [CSV](https://) Please find below an example of data in CSV format in tabular format.