Bitcoin can only go Green by dropping the Proof of Work and moving to an alternative such as Proof of Stake.
The PoW miners have centralized control of bitcoin thru their PoW Mining Equipment, giving that up would give up their control.
They will never do it.
If you want energy efficiency, look into the alts as bitcoin is dead in the water on ever fixing their energy waste problem.
Sir i just got your words, but in case of PoS the New block is found through a deterministic way ( i read in google) , and it depends upon the stake and records. Does it mean the pool with maximum assets will find the block faster ?