Because increasing the number of transactions does not significantly change energy cost. Bitcoin's daily energy cost will asymptotically approach (price per co

Because increasing the number of transactions does not significantly change energy cost. Bitcoin's daily energy cost will asymptotically approach (price per coin)*(daily miner reward amount). As block reward decreases, we may see less energy investment in the future. There is a loose link between number of transactions and price (network effect of more people using Bitcoin increases perceived value), but its probably a fairly small correlation.