forecast-solar 5.0.0

Asynchronous Python client for getting forecast solar information

Python API fetching Solarpanels forecast information.

About

With this python library you can request data from forecast.solar and see what your solar panels may produce in the coming days.

Installation

pip install forecast-solar

Data

This library returns a lot of different data, based on the API:

Energy

• Total Estimated Energy Production - today/tomorrow (kWh)
• Estimated Energy Production - This Hour (kWh)
• Estimated Energy Production - Next Hour (kWh)
• Estimated Energy Production - Remaining today (kWh)

Power

• Highest Power Peak Time - Today (datetime)
• Highest Power Peak Time - Tomorrow (datetime)
• Estimated Power Production - Now (W)
• Estimated Power Production - Next Hour (W)
• Estimated Power Production - In +6 Hours (W)
• Estimated Power Production - In +12 Hours (W)
• Estimated Power Production - In +24 Hours (W)

API Info

• Timezone
• Rate limit
• Account type
• Rate remaining

Validation

• API key (bool)
• Plane (bool)

Example

import asyncio

from forecast_solar import ForecastSolar


async def main() -> None:
    """Show example on how to use the library."""
    async with ForecastSolar(
        api_key="YOUR_API_KEY",
        latitude=52.16,
        longitude=4.47,
        declination=20,
        azimuth=10,
        kwp=2.160,
        damping=0,
        damping_morning=0.5,
        damping_evening=0.5,
        horizon="0,0,0,10,10,20,20,30,30",
    ) as forecast:
        estimate = await forecast.estimate(actual=2.315)
        print(estimate)


if __name__ == "__main__":
    asyncio.run(main())

Multiple Planes

If you have solar panels facing different directions, you can specify multiple planes.

Note: Using multiple planes requires both an API key and a Personal Plus (or higher) subscription. If no API key is provided, additional planes will be silently ignored. See the subscription plan overview for more information.

import asyncio

from forecast_solar import ForecastSolar, Plane


async def main() -> None:
    """Show example with multiple planes."""
    async with ForecastSolar(
        api_key="YOUR_API_KEY",
        latitude=52.16,
        longitude=4.47,
        # First plane (primary)
        declination=20,
        azimuth=10,
        kwp=2.160,
        # Additional planes
        planes=[
            Plane(declination=30, azimuth=-90, kwp=1.5),  # Second plane
            Plane(declination=25, azimuth=90, kwp=1.0),   # Third plane
        ],
    ) as forecast:
        estimate = await forecast.estimate()
        print(estimate)


if __name__ == "__main__":
    asyncio.run(main())

ForecastSolar object

Parameter	value type	Description
api_key	str	Your API key from forecast.solar (optional)
declination	int	The tilt of the solar panels (required)
azimuth	int	The direction the solar panels are facing (required)
kwp	float	The size of the solar panels in kWp (required)
damping	float	The damping of the solar panels, read this for more information (optional)
damping_morning	float	The damping of the solar panels in the morning (optional)
damping_evening	float	The damping of the solar panels in the evening (optional)
inverter	float	The maximum power of your inverter in kilo watts (optional)
horizon	str	A list of comma separated degrees values, read this for more information (optional)
planes	list[Plane]	A list of additional Plane objects for multi-plane setups. Only used when an API key is provided (optional)

Plane object

Parameter	value type	Description
declination	float	The tilt of the solar panels (required)
azimuth	float	The direction the solar panels are facing (required)
kwp	float	The size of the solar panels in kWp (required)

estimate() method

Parameter	value type	Description
actual	float	The production in kWh for the current day so far. Only used when an API key is provided (optional)

Contributing

Would you like to contribute to the development of this project? Then read the prepared contribution guidelines and go ahead!

Thank you for being involved! :heart_eyes:

Setting up development environment

This Python project relies on Poetry as its dependency manager, providing comprehensive management and control over project dependencies.

You need at least:

• Python 3.12+
• Poetry

Installation

Install all packages, including all development requirements:

poetry install

Poetry creates by default an virtual environment where it installs all necessary pip packages.

Prek

This repository uses the prek framework, all changes are linted and tested with each commit. To setup the prek check, run:

poetry run prek install

And to run all checks and tests manually, use the following command:

poetry run prek run --all-files

Testing

It uses pytest as the test framework. To run the tests:

poetry run pytest

To update the syrupy snapshot tests:

poetry run pytest --snapshot-update

License

MIT License

Copyright (c) 2021-2026 Klaas Schoute

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.