I've made some inroads in determining the electricity cost of securing the network:
http://organofcorti.blogspot.com/2013/06/125-cost-of-securing-network.html3. Summary
Main points:
Network electricity use is governed mainly by users with hashrates up to 20 Ghps
At 10 MW and an estimated average electricity cost of US$ 0.15 per kWh, the cost per day of securing the network is US$36000 - not hundreds of thousands of dollars per day, as new sites estimated.
Also:
We have an estimated 30000 user accounts in the network
The network has doubled in hashrate since April 14th, but the total electricity use has increased by only a third.
A large number of CPU and GPU miners came and went in April - and had no significant effect on the hashrate, but a very large effect on the total electricity use.
However to make the estimate more robust, I need some help, and I've posted a survey:
https://docs.google.com/forms/d/1EgNjL-N6mMEfOsDup2Pr7I5B9sM2LUVZOGcddcBCEFI/viewformIt looks a bit long and daunting, but most miners will only have to answer ten questions or less, and it should take less than ten minutes. I'll make the data publicly available to whomever wants it.
Also, sorry about having to get you to convert your local electricity costs to US$ - the conversions were going to be a headache!
Cheers all!