I don't know anything about proof-of-stake but Chia by the inventor of bittorrent (Bram Cohen) uses Proof of Space/Time by using extra commodity hard drive spac

I don't know anything about proof-of-stake but Chia by the inventor of bittorrent (Bram Cohen) uses Proof of Space/Time by using extra commodity hard drive space instead of special-purpose CPU cycles: https://www.chia.net/ https://www.chia.net/ Their mainnet has been out for a month and people are able to mine ("farm") using low-energy hardware. There are people that are farming petabytes of storage with a single Raspberry Pi. I myself am using an old crappy laptop with some unused hard drives I had around the house.