Good work npl, a .30 cent transaction fee is already starting to get heavy, the only reason it's toterable is that users are still shielded from it by the debasement coins being paid to miners.  I suspect we will have another lowering of minimum fees at this rate.  I can't stress how much this already well established and now EXPECTED practice of fee lowering demonstrates that the BTC really has no intention of ever being transaction fee supported.

Your estimate of Electrical costs, can you summarize how you arrive at it?  Are you assuming all ASIC?  I think their are still a lot of inaccurate estimates floating around from the GPU era.  The best ASICs are around 1 J/GH which would mean the 5 million GH/s are consuming 5 million J/s or 5 million watts, or 5,000 kW, or 5MW (the output of a very small power-plant but not really that much in the grand scheme of things).  5MW times 24 hours is 120,000 kw/h, times 15 cents a kw/h is just $18,000 a day.  Naturally a lot of the mining hardware is a generation or two behind so an estimate of as much as 10 times as much is'nt unreasonable, but we would want to discount these marginal miners because the network truly dose not need them.

So with Transaction fees in the ~$30,000 range it looks like the fees are roughly able to pay for electricity, a somewhat surprising result actually.  The problem is that hardware acquisition and depreciation is now the primary cost to miners, and we fully expect electrical costs to continue to rise as more miners come online.