Earlier quoted context omitted.
> Icarus Investments High efficiency, high energy solar solutions using phase change in solid hydrocarbons for energy capture.
Until I learned about the mechanics of it, I thought it would be a glorious idea to have e.g. metal rods placed in the Sahara that would contract at night and expand at day (due to the high temperature differences) and extract energy from the movement. Counter to young me's expectations, thermal expansion is not some infinite force, and if you run the real physics, the low frequency makes it not worth the material in…
And the wax thing can work, you just need wax that's energetic enough to count as an explosive. I haven't worked out the recovery phase yet, granted; but with a few billion dollars I'm sure it can be made to work.