In early days what most people had in their home as home Appliances was a bulb, fans, refrigerator (some didn’t have it) and ovens, etc. which would run on AC. If you look what’s now we have, we have much more stuff at home that runs on electricity and most of them use DC. However, we still get AC supply that we have to convert first to DC and that is why adapters are sold for and they are a part of every electronic item we buy now. You are most probably reading this on a laptop which might be connected to an AC outlet but in between the chord, there is an adapter which is converting AC to DC. If you are reading this on a phone then charging a phone means plugging it to a 5v DC source like a wall charger or USB port. What about the lights in your room? It might be LED bulb that is although plugged in the same lamp where you used to put an incandescent bulb is actually having a small circuit inside it to convert the voltage to DC first before sending it to the LED. All these appliances at home depend on Smps circuits to convert AC to DC. These SMPS although better than older linear power suppliers are still not very efficient and there is some loss of power when converting from AC to DC. Most of this loss is in the form of heat. Now you know why a cheap Chinese charger will heat more than a genuine branded charger because the former is cheaply built and is not very efficient. Remaining few appliances that do not use DC in our home are Air conditioners, toasters and ovens and ceiling fans (although now we have more efficient BLDC fans that work on DC).
When most of the appliances and devices use DC, why not switch to DC supply instead of AC? Think of the benefits of it, first of all, no more power bricks or chargers or adapters. All you need will be a simple DC to DC converters that are so small that a laptop or phone can have them built it. The prices of many gadgets that use SMPS will reduce because there will be no SMPS required.
My way of switching to DC will be to use AC for long distance high voltage power lines (because source from the turbine will be AC) then converting them to DC at sub-stations and supplying it to homes.
