Speaking of suboptimal analyses.

The human isn't a single core, 100% pegged on that task for those 20 minutes. Even actively working at something that energy consumption is likely to be less than 10% of that. There's a whole lot of energy being burned by the cardiovascular system, respiratory, digestive and renal, endocrine, muscular system (all that typing, moving and focusing of the eyes), and we haven't even got to the energy of the "OS" execution in the brain to control all that.

I don't think your numbers are the insight you think they are, nor accurate - not even particularly close.