All of the comments in here that are saying something like, > "well at Bitcoin's current throughput it consumes X, and $large_financial_institution does Y, Bit

All of the comments in here that are saying something like, > "well at Bitcoin's current throughput it consumes X, and $large_financial_institution does Y, Bitcoin's equivalent energy usage would be Z" have a fundamental misunderstanding of Bitcoin's mining. The current difficulty to a produce a block is the same, regardless of the transaction throughput of the system. The Merkle root of the block's transactions goes into the block header, and that is hashed over and over. Empty blocks or huge blocks would require approximately the same energy in mining effort.