The stardust is a given. As for sunlight, all the energy including somewhat arguably geothermal (using the suns gravity to help form the earth and I guess radioactive material being formed by other stars) comes from the sun and gets converted into chemical energy you eat so you’re stardust animated by sunlight (mainly).
So a coal plant is sort of running on solar power? Sure it took millions of years and a few extinction events to make that coal, but it’s technically renewable, right?
If you could make the sun go boom in a supernova, nuclear power would be renewable too.
Yes it’s converted and stored solar energy and it is renewable if you wait long enough but not on any reasonable timescales for human society. The sun isn’t big enough to become a supernova but if it did I guess you could argue if you wait long enough the material would most likely form other stars a few times until the stellar era of the universe winds down which will happen with or without any beings extracting energy to perform work.
Yeah, it seems that the sun just isn’t big enough for that sort of thing. As the universe is also expanding, the uranium we find in this system is probably locked in here until the heat death of the universe.
If you could expect the elemental cycle to continue forever, you could argue that the elements of nuclear waste would eventually end up in a star which would recycle them into new uranium. The expanding universe makes that highly unlikely, so even in extremely long time scales, nuclear power isn’t really renewable at all.
If the big crunch hypothesis turns out to be true, there would be an infinite cycle of new universes, and that would make every element renewable in extremely long time scales. However, the ultimate fate of the universe isn’t particularly clear at the moment, so who knows really. For the time being, I’ll just assume that the heat death is the most likely outcome.
Yes in the long term there’s no such thing as renewable energy since entropy always increases. It’s a misnomer that only has meaning in small human timescales.
Yeah if the big crunch is accurate and the universe is eternally expanding and contracting then all energy is renewable. Although this is way way outside the scope most normally have in mind when speaking about renewable energy.