Thanks for the sources. Crypto is a fascinating development, and it's good to see so many blind men feeling their own part of the elephant.

It is difficult to critique any of these texts without reading them, but I would venture a comment or two anyway.

First, bitcoin cannot be legal tender because debts are not denominated in it. Gold and silver are legal tender only in accordance with a law fixing the dollar value. "Legal tender" is proof that you have offered to pay your debt. If you owe me $100, you can give me $100 in legal tender, and a court will recognize that the debt is extinguished. But unless the value of bitcoin is fixed by law, we can't know that any given number will satisfy your obligation. Someday, a stablecoin may be legal tender, but a fluctuating asset can never be legal tender.

Regarding the use of renewable energy to mine bitcoin, the general idea seems to be that stranded, intermittent, renewable energy can be used for computing, and the useful information resulting from that computing can be utilized more easily than, say, electricity generated by that energy. But, granted that computing is a wonderful use of remote energy, why is bitcoin mining the best use of computing? That seems to me the case that needs to be, but cannot be, made.