The stuff in your house that "switches to DC internally" isn't switching to 100,000 to 800,000 volts[1], which is what the HVDC is that the article is talking a

The stuff in your house that "switches to DC internally" isn't switching to 100,000 to 800,000 volts[1], which is what the HVDC is that the article is talking about. Running DC in your house isn't going to eliminate any voltage conversions that are already going on, they will just be DC-DC converters with 48vDC (or whatever) input rather that 120vAC input. Most of the stuff in your house isn't even running on the same voltages internally... most of the electronics nowadays use many voltage "rails": * 17-19v laptop chargers (the voltage has to be higher than the battery's voltage in order to charge the battery) * 12v for older hard drives * 5v for not quite so older hard drives and older logic * 3.3v for newer logic and newer hard drives * A veritable plethora of sub-3.3v rails for CPU chips and other high tech chips. * 120vDC for "universal" motors unless you replace all your appliance motors with 48vDC (or whatever) motors In addition, the current requirements of running at a non-lethal DC voltage inside your house would require much larger wire gauges than your current wiring in order to keep the resistive losses reasonable[2]. The rewiring costs would be staggering. [1] http://en.wikipedia.org/wiki/High-voltage_direct_current http://en.wikipedia.org/wiki/High-voltage_direct_current [2] Charts for 12v wiring, 48vDC would be 4x better, but still not good - http://www.westmarine.com/webapp/wcs/stores/servlet/WestAdvisorView?langId=-1&storeId=11151&catalogId=10001&page=Marine-Wire http://www.westmarine.com/webapp/wcs/stores/servlet/WestAdvi...