The only energy source that is totally reliable and predictable is
either tidal - as long as the moon stays in orbit! - or less
predictable wave energy. The amount of power that can be harnessed
from tidal and wave movement is huge. I visited a site on Pico,
Azores where a simple concrete box with an air tubine (Oscillating
Water Column) produces 400kW from the waves.

Otherwise, the world needs to loose 3-4bn people fast. We are no
different to the population cycle of lemmings.