Forecast.Solar

Solar production, weather and time windows data are provided for up to 7 days with a resolution of 1 hour down to 15 minutes.

If you then checked the documentation and you like it, register an account for more features.

For the forecast, these 2 data points are mainly used in each case:
- historic irradiation data from PVGIS per plane combined with -
- weather forecast data per location from several weather services -

From the actual weather forecast for the location (with a possible offset because there are not so many stations around), we use e.g. the cloud coverage factor and the temperature forecasts, the cloud coverage is the most important, the temperature is relevant in hot summers when the modules can have > 70 °C which lowers the performance.

The figure shows the areas covered by the Photovoltaic Geographical Information System (PVGIS) solar radiation databases and therefor by Forecast.Solar. With the latest update PVGIS 5.2 almost the entire world is now covered!

(Click to enlarge)

The API can deliver responses in JSON, CSV or XML

The Swagger compatible API definition is available in YAML.

Example: Get solar production estimate

You can easy build and test the required URLs with the Swagger-UI.

Request

https://api.forecast.solar/_your_API_key_/estimate/54.9/25.3/37/0/1

Response (professional account, 15 minutes resolution)

{
    "result": {
        "watts": {
            "2019-06-22 05:15:00": 17,
            "2019-06-22 05:30:00": 22,
            "2019-06-22 05:45:00": 27,
            ...
            "2019-06-29 20:15:00": 14,
            "2019-06-29 20:30:00": 11,
            "2019-06-29 20:45:00": 7
        },
        "watt_hours": {
            "2019-06-22 05:15:00": 0,
            "2019-06-22 05:30:00": 6,
            "2019-06-22 05:45:00": 12,
            ...
            "2019-06-29 20:15:00": 2545,
            "2019-06-29 20:30:00": 2548,
            "2019-06-29 20:45:00": 2550
        },
        "watt_hours_day": {
            "2019-06-22": 2626,
            "2019-06-23": 2918,
            "2019-06-24": 2526,
            "2019-06-25": 2866,
            "2019-06-26": 2892,
            "2019-06-27": 1900,
            "2019-06-28": 2199,
            "2019-06-29": 2550
        }
    },
    "message": {
        "type": "success",
        "code": 0,
        "text": ""
    }
}

You can direct draw chart for solar production estimate using the Forecast.Solar widget.

(Professional account upwards)

Chart for the geographical midpoint of Germany at  51°9'N,10°27'E  with a declination of 37°, looking south with 10 kilo watt peak installated.

It is also possible to show charts of the historic average data and the theoretic data for clear sky conditions.

Please refer to the documentation for details and check also the example page.

The Script URL was build with: https://api.forecast.solar/demo-key/chart/51.15/10.45/37/0/10

With the increasing share of photovoltaics in the electricity market, the importance of Solar energy forecasts. These are an important tool for the integration of Solar power into existing network structures.

The production of solar power is dependent on external influences on which man has no or only limited influence. For example, Season, time of day, weather (eg ambient temperature, sun/clouds, air turbidity).

A solar day covers the global energy supply for eight years.

Predictions about the availability of solar-generated electricity in the future support private power management, but are of great importance, above all, for commercial solar power generators and network operators.