i appreciate your engagement. i checked the links provided and they are more self-referential "research". there's no real study behind any of these "analysis" beyond what i would call napkin math of taking a series of estimates to emerge with a cost to mine bitcoin.
for example, very simplistically, you can take guess at the cost to mine using the mining rate of a typical miner and multiply that by the cost of electricity, and then obfuscate that behind some more hogwash, but that simplistic analysis is grossly inaccurate because it assumes that all miner's are using the same electricity rate. for example, bitcoin thrives on cheap electricity. cheap electricity comes from lost or stranded sources and contributes to the hashrate.
there are also power sharing agreements in place where bitcoin miners operate as a consumer of last resort and turn themselves off when the grid demands them to.
in the end, what im saying is the original article has no citation and there is no good study that concludes with any accuracy whatsoever what the cost to mine a bitcoin really is. you can guess at it, but you'll never know. the only insight that could be close to accurate would be based on whatever disclosures a publicly traded company made in their required filings.