We need altcoins as long as we interact economically over the net, with people we do not know (or simply with people outside our local communities). If we try to imagine what qualities a “solarpunk coin” should have, what are your thoughts? Do we know any existing coin, checking all boxes? This question is more about political economy of Solarpunk, then its technology.
Blockchain is just another name for a public (distributed/shared) ledger. Due to scaling and privacy issues of that, this method is inherently unsuited for direct payment use, but it could be useful for an inter-bank exchange market of local currencies.
…which is ideally / eventually the usecase for the coin I am thinking about.