Possible to estimate, yes; but I don’t see how it could be easy.  That would require cost/efficiency estimates for every generation of miners:  CPU (various optimized implementations and CPU models), GPU (ditto), FPGA, every generation of ASIC...

Does a collection of those historical data even exist anywhere?  If you folks discussing this were to gather in the first instance, the effort may be worth a research paper.  Maybe one already exists (with data up to some past point).


I don’t think that the historical electricity cost would give a clear view of the current security of the Bitcoin blockchain.  With ASIC hardware, you could easily outrun the whole early CPU-mined Bitcoin network at drastically lower energy cost!  Of course, as you continued rewriting blockchain history, sooner or later, you would slam into the historical point at which the real Bitcoin network’s hashrate exceeded your hardware’s capabilities.  From that point onwards, you would just get further and further behind with your fake blockchain, as the chaintip of the real Bitcoin network keeps advancing faster than you can chase it.*

Still, yes, the energy-cost accounting would be historically interesting.


The real kind!

(* And one of the marvellous properties of the Nakamoto Consensus is that the “real” chain can be selected by an isolated node with no information except the block data alleging one or more consensus-rule valid chains.  Most-work (not “longest”) chain wins, and that’s that.  Not even a trustworthy realtime clock source is required.  It is the whole point of how this is supposed to work; but somehow, I often see people missing it—usually when they want to suggest some “improvement” which would break Bitcoin’s security without even achieving what they expect.)

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Is that investment advice to avoid shorting my lifetime at high leverage by posting on an Internet forum?  Confirmed math and science calculate that writing on the Internet brings −99.53088288% ROI.