Working on it...
Don't worry @Hueristic. I'll use the network hash rate in my calculation to ensure the energy usage from all miners is included.
edit: SMF seems to insert superfluous breaks when translating BBcode to HTML.
edit2: Wow. Tables
really suck in BBcode.
edit3:

Yeah these tables are rough...
I have no Idea how you can differentiate between base systems, gpu miners, fpgas and asics over time. The overlap is huge and due to locations their profitability is widely varied so you would have to make massive assumptions. Literally this could take a person a lifetime to get within a small tolerance of error.
Not to mention it is widely believed satoshi (and others) used custom FPGAs and how those could be calculated is beyond me.
It's certainly going to take a while to compile the data we'll need but I think we're going to find that recent mining of blocks far outweighs earlier mining in terms of the power requirement. My hope is that it will be enough of a difference to make the error very small even with the assumptions that will have to be made.