Chalo says it all right here.
Chalo said:
Household switches would be large, heavy, expensive, and short-lived. There would be substantial transmission losses if distribution were DC, and substantial local rectification costs if distribution were AC and residential service were DC.
Convince people to reproduce at less than replacement levels, and then we can discuss soaking extra per capita infrastructure costs.
AC is less expensive and easy to generate than DC. The distance covered by AC is more than that of the DC. The power loss during transmission in AC is less when compared to the DC. AC is the current of choice for power plants and the electrical grid as a whole. When a plug is connected to an electrical outlet, alternating current comes out, providing power to countless devices like light bulbs and refrigerators. AC is preferred for this application. Contacts would erode whenever an inductive load is place upon the proposed 48v line service, and when it was pulled from the socket. Sparks even. Low maintenance costs of high speed AC motors. So much easier to interrupt the current (ie. with a circuit breaker) due to the current going to zero naturally every 1/2 cycle. For example, a circuit breaker can interrupt about 1/20th as much DC as AC current. The modification of AC can easily be operated using particular transformers either step-up type or step-down form. The magnitude or value of alternating current can be easily reduced without the waste of extra energy. This can be performed by employing a choke coil. AC can be relatively easily and economically stepped up or down with a transformer to suit the application. AC can be easily converted to DC if required. DC cannot be wired through a transformer. So we would have to redesign ALL the microwaves, computers, refrigerators, ceiling fans, heating home systems... high power AC systems.... ect...
Dont get me wrong: Your idea basically is sound and in application: I see that we DO use DC every day, at low levels, in our homes, charging phones, running computers, and TV, and anything else that might have a switch mode power supply inside it, .. There are certainly standards written into the codes that address the distribution networks and requirements of DC current in use by consumers in the homes, and other zones, today. Certainly code for DC network power distribution. Alot of the AC, that comes into the average home, ends up as DC, inside the computer, or inside the iPhone, or used, consumed, viewing the TV, or to power the servers, that keeps the internet running.
If you want to live off grid? Yes. Go 48v for the base of your systems power source. IF you want to live out back, in the Australian woods? Yes. Go 48v. Yes yes yes, a 48v system is GREAT for a Recreational Vehicle with a solar farm on the roof: Easy hookup to powerful inverters, DC load center to handle all the fusing,: Breakers that are rated for the AC applications in teh same load center: AC and DC available and easily replenished by your solar farm and stored: Or your windmill, or your water turbine on the stream..... Yes. However, rewiring the world for the new advantages of DC is not really a feasible option. In my opinion.