Tidal energy is not renewable! We'd be tidally locked to the moon in 1000 years if we used Tidal for 1% of our energy consumption.
That would mean we’d be well into the type 1 civilisation about 10^19W a year and we’ll be on the way to a type 2 civilisation.
SF authors (like David Brin) have screwed up on this very topic.
Lasers can be used for cooling, by shining a laser on a target carefully set up so that anti-Stokes scattering carries away entropy. The light scattered is quite incoherent, though.
There may be some neat tricks, this is an area I know I'm not good at, but you have to be very careful.