Following an earlier article comparing various GPU hardware for Bitcoin mining, Ryan Shrout (@RyanShrout) of PC Perspective put out a power usage costs comparison:
Looking at the potential profitability of [Bitcoin mining] the actual real-world cost of running a mining machine 24 hours a day, 7 days a week becomes much more important.
If you are in the market to build a system for Bitcoin mining you should obviously be aware of how the cost of power will affect your profits and loss.
If you decided to Bitcoin mine on a GeForce GTX 590 you would actually lose $776 in your first year living in the northeast, California, etc. In fact, NO cards from the GeForce lineup would make you a profit in the first 365 days after purchasing the card.
Even if you already own the card today, the power it costs to run the GTX GPUs might exceed the value of the Bitcoins you can mine over that same period.
Though Ryan’s analysis was limited to the U.S., his consumption numbers can be used along with rates from elsewhere in the world.
Additionally, only the published averages are used. In the U.S., many areas have utility rates that are meant to encourage conservation.
Thus the electricity consumed for mining should be calculated using the rate at the highest tier – a rate that can often be double the average rate. Other areas have time-of-use pricing meant to drive consumption to off-peak periods.
Do keep in mind that the profitability numbers shown in the analysis are entirely dependent on the future difficulty levels and the BTC/USD market exchange rates. Additionally, just like how GPU mining took just months to wipe out completely the previous method (CPU mining), there could be an ASIC or FGPA solution that puts GPU mining out to pasture.
However since every bitcoin that is issued goes through the hands of a miner, those with capable equipment are in position to profit should the exchange rate resume its ascent like the one seen in May or early June.