Science

The reference from which the truncated equations appear is this one: Dong Hyup Jeon, Seung Man Baek,
Thermal modeling of cylindrical lithium ion battery during discharge cycle, Energy Conversion and Management, Volume 52, Issues 8–9, 2011, Pages 2973-2981.

The paper, unlike many papers in which symbols for the variables are defined in the text, has a table of symbols for variables and their meaning.

This is it:



The full equations, as opposed to those posted in the quiz are these:



The definition of "q_entropy" with a dot includes one of three possible secret words that would have won a heart.

These are: "entropy" (of course), "heat" and "resistance." ("Internal resistance" would have justified two hearts.)

These words reflect the reality that storing energy wastes energy, therefore storing energy is not "green." There was a diversion in the thread about whether storing so called "renewable energy" is "green," which I found very annoying, since there is essentially no where on the planet where there is such a surfeit of so called "renewable energy" as to matter. So called "renewable energy" remains a trivial (and very expensive) form of energy that has done nothing, zero, zilch, to arrest the extreme global heating we now experience. In fact, if one looks, it made things worse:

If one looks at a grid where there is a lot of batteries - California is an excellent place to see this and can be accessed at the CAISO website - one will see that batteries are being charged while dangerous fossil fuels are being burned, with the dangerous fossil fuel wastes being dumped directly into the atmosphere. Since storing energy wastes energy, it follows that charging batteries while burning gas means that more dangerous fossil fuel waste is being dumped than would be if batteries did not exist. In other words, batteries make things worse, not better. The lie that there is so much so called "renewable energy" on the planet that it justifies mining the shit out of the same planet to make batteries is just that, a lie. It's not just wasteful; it's obscene. I found the entire exchange annoying, since the multitrillion dollar so called "renewable energy" industry is an economic and environmental nightmare that has been useless in arresting extreme global heating. All it has done is to render precious wilderness into industrial parks.

These remarks apply, in spades, to hydrogen, which is even worse than batteries.

Although the "contest" generated no responses, a heart was awarded for being an organic chemist, albeit apparently one that left physical chemistry behind. I've been an organic chemist, but I'm kind of happy that my career did not leave physical chemistry behind; it inspired me to embrace it, although I became a chemist because I loved organic chemistry, in particular synthesis, although that's not how my career ended up.

The only justification for the toxic chemical nightmare of batteries are cases where they capture exergy that would otherwise be wasted, as in a hybrid car. Even there, the case is weak, although I have personally embraced that practice - while being aware of the moral and environmental cost, which in some sense makes me worse than other people - as much as I own and drive a hybrid car. It isn't "green." It's just slightly less odious, particularly if one is willing to ignore the moral cost of nickel mining in Siberia and His Maggotcy King Eloon's the first (and hopefully the last) practice of holding cobalt slaves in Africa. (In the case of the generation of primary energy, waste energy can be best stored as heat with minimal losses, upgraded or otherwise, which can thus capture lost exergy; this is only really an option in nuclear plants and to my knowledge isn't practiced anywhere except China, and possibly may be practiced in Wyoming if the Terrapower plant is completed.)

Thanks for reading if you have done so. Have a nice weekend.