[recuter]

I raise you a wax motor:

https://www.youtube.com/watch?v=MiADday0mDA

https://en.wikipedia.org/wiki/Wax_motor

tl;dr - sun rises, temperature rises, wax material expands, motor actuates, solar panel tracks the sky as if it was a sun flower. Maybe the gloop is sentient or something.

[freemint]

Variation in temperature between days (summer vs winter) is larger then variation between morning and afternoon.

[recuter]

And? I was going to type out a reply but got me curios whether this is a solved thing already.

It is a thing already: http://www.sulasindustries.com/technology/