I am tired of see the "environmental Disaster" stories from reporters that take the data from blockchain.info so I did a rough estimate for ASICs.
http://cointext.com/electricity-usage-of-bitcoin-mining/
http://cointext.com/electricity-usage-of-bitcoin-mining/
Yup, don't let the facts get in the way of a good story!
So the orginal Bloomgerg journalist used a metric that became useless when FPGAs arrived (early 2012) and made a conclusion based on the total capacity metric from late March 2013 in which he was off possibly by more than an order of magnitude.
But that's the crap journalism you have today, if he had used accurate numbers he wouldn't have a story.
So there you have it.
Earlier this year right before ASICMINER and Avalon got their first units into production there was a total of 22 Thash/s. Of that, some is GPU and some is FPGA. Who knows the split. It might be fair to give that a 2/3rd GPU and 1/3rd FPGA split, so that would be about 15 Thash/s is GPU and 7 Thash/s is FPGA. With the increase to today's 83 Thash/s, the entire increase is likely ASIC. So that's 61 Thash/s of ASIC. (I'm going to go even further and attribute further drop where GPU today has probably decreased to well under 10 Thash/s thanks to GPU miners having greater profits today mining Litecoins).
But even take the scenario of the 83 Thash/s consisting of: 15 Thash/s GPU, 7 Thash/s FPGA and 61 Thash/s ASIC.
A rig w/ 3 5970s consumes about 1100W and does 2.1 Ghash/s. So 7,142 of those rigs do 15 Thash/s. That's about 188 mWh per day, costing $29K for the electricity.
An FPGA is more efficient than a GPU, with a BFL single doing 0.83 Ghash/s on 80W. So the 8,433 FPGAs do the 7 Thash/s.. That's about 16 mWh per day costing under $3K for the electricity.
An ASIC is uber efficient. An Avalon ASIC does 60 Ghash/s on 600W. So if all ASIC mining today were Avalons, there'd be 1,016 of them running to get 61 Thash/s. That's about 14.6 mWh per day costing under $3K for the electricity.
Incidentally, the BFL chips are even more efficient than the first generation Avalons, so the BFL Jalapeno does 5.5 Ghash/s on 30W ... meaning if all ASICs were BFL Jalapenos there would be under 8 mWh per day consumed, costing under $2K for the electricity.
But a headline that says 3/4ths of all bitcoin mining today consumes under $2K per day of electricity doesn't have the ring that "environmental Disaster" has.
Irresponsible, agenda-driven reporting is all it is.
They simply throw their credibility out the window.
