There is non-profit startup in Berlin trying to do this, they mainly fund themselves by raising the money from the crowd. It's a lottery system where one can win 1000€ per month for one year, which in most parts of Germany gets you somewhere. They already funded 29 people analyze and blog about who won. Most people actually didn't do dramatic life changes, which also could be because it's just one year.

Warning German: https://www.mein-grundeinkommen.de/start