I don't think that there is a way for that to happen. The difficulty of each Bitcoin block is just too high and the need for electricity from the power hungry GPUS are necessary for the network to run. Like, we could use renewable energy, however i'm not sure any individual can possess that much power as to own an entire enrgy rig made up of solar panels. If you truly want Bitcoin mining to be more renewable, try asking people to try forks for mining and alts because there is NO WAY that any implementation plan can affect BTC's energy use in the long term.