dream: 
BTC mining follows earth's rotation - as night falls and energy usage decrease, unused hydropower mines BTC.
then someone plots an earth 3D globe with red points on hashes' IP locations -> and night turns red on black.

lots of water needs to flow, even when less energy is needed.
In tropical rain seasons, lots of unused water flows through non-energy generating waterways.
BTC mining could even make installing extra turbines profitable.
And in dry times with not enough water flow... just stop mining. no one is harmed.

plus... when I see an oil refinery burning unused gases... I think how much BTC could be mined from that.