Well, sort of. If a bunch of these computers were made pre-2005 or so and were just sitting idle for the time they otherwise would've been mining bitcoins, then using them for mining is in fact a more effective use of electricity that was being used anyway. In newer systems though, substantial engineering hours have been spent making sure that just about every component or interconnect can enter a low power state if it's not currently being used. Based on the graph here a third of the way down the page you could expect Bitcoin to require at least 50% more power than platform idle, although in my experience it might be more like 80%, so this is a legitimate concern on the level of your individual power bill even if computers aren't a chart-topper for worldwide power consumption.It’s a stunning stat, but does this really count as a “disaster”? That’s less clear. After all, we need to consider the counterfactural: Is it possible that these computers would be used for other activities and calculations anyway, if they weren’t mining Bitcoins?