GreenFediverse is a directory of Fediverse instances with information on how environmentally friendly they are. You can follow the project here:
You can see the directory at https://greenfediverse.frama.io/green-instances/
The project uses data from the Green Web Foundation, and is mainly based on whether the instance's hosting provider uses renewable energy.
This is a brand new server run by the main developers of the project as a spin-off of mastodon.social It is not focused on any particular niche interest - everyone is welcome as long as you follow our code of conduct!