Those stats assumed CPU/GPU and FPGA, not ASIC, miners.
For instance, the 5-to-500-gigahash-per-second rigs would have to be running at over 300k watts of electricity using those statistics. :)
So in reality, the network is much more efficient -- the high-end miners are using more than 100x less electricity (which would still be 3000 watts for high-end rigs per those numbers), and probably closer to 1000x less, than those estimates.
The block size is not the limit here; the protocol aims for one block every 10 minutes so that users don't have to wait too long to get a transaction confirmed.
Cost per transaction would go down drastically with increased usage.
Those stats assumed CPU/GPU and FPGA, not ASIC, miners.
For instance, the 5-to-500-gigahash-per-second rigs would have to be running at over 300k watts of electricity using those statistics. :)
So in reality, the network is much more efficient -- the high-end miners are using more than 100x less electricity (which would still be 3000 watts for high-end rigs per those numbers), and probably closer to 1000x less, than those estimates.