Here's a video of me experimenting a little bit with my 4x10 solar panel, a tub of water, and a coil of copper tube submerged in that tub.
This morning, there was a half inch of ice on the the top of the tub of water, but the water temperature was 140 degrees only three hours later!
I also didn't realize that the YouTube thumbnail choose the frame where I have the word "Stratification" on the screen. It's like our vocabulary word for the day!