This custom component (installable via HACS) is an upstream version of growatt_server integration that is part of the Home Assistant Core repository.
The integration has been through a period of instability due to various issues with the authentication mechanism for Growatt (Growatt keep blocking the python library), using the HACS system will allow for more dynamic responses to the changes made by Growatt.
The changes made in this repository will be rolled up monthly and then submitted as a Pull-Request to the main Home Assistant Core repository for release as an 'official' Integration.
Note - This Integration works not only with Growatt systems but also Jinko Solar systems (as they appear to be exactly the same systems & API).
Since 07/02/2023 (7th Feb) Growatt have started implementing rate limiting and blocking to user accounts that make excessive API calls i.e. this integration. There is an extended discussion around it here.
If you're interested in the short version read these posts: first, second, third
The recent developments throw into question the long-term viability of this Integration, please see the 'third' link above for the proposed plan.
On initial release this plugin is an identical copy of the original integration that was part of the Home Assistant release. Going forward, this will be the upstream release of the Integration and the first place that bugs are fixed & new features are added.
This integration can be installed via HACS for Home Assistant
https://github.com/muppet3000/homeassistant-growatt_server_api
Growatt Server API