I don't think you can directly compare the prices of the coins, but you need to look at the reward that's at stake. 12.5 bitcoins every 10 minutes at 7277 USD/

I don't think you can directly compare the prices of the coins, but you need to look at the reward that's at stake. 12.5 bitcoins every 10 minutes at 7277 USD/bitcoin = 9096 USD/minute 3 eth every 14 seconds at 132 USD/eth = 1697 USD/minute then you'd expect the bitcoin miners to use 5.3x the energy of eth EDIT: oh, someone already did the same calculations earlier a couple of comments below :)