Biomass can cover a range of technologies, some of which are greener than others e.g. if you capture methane from landfills or anaerobic digestion of organic waste then the absolute best thing to do would be to turn it into chemical feedstocks, but burning it for energy is definitely better than just letting it rot and escape into the atmosphere while also burning using fossil methane gas

Nuclear is renewable through seawater extraction: https://www.forbes.com/sites/jamesconca/2016/07/01/uranium-s...

If we want to get pedantic, there's a finite amount of fissile material. But then again solar isn't technically renewable either, since there's a finite amount of hydrogen in the sun.