Thought provoking question! I am not an electrical engineer, but arguments I heard went along these lines: Almost all existing appliance markets are AC. Are we really going to be building a complete parallel appliance market? You wouldn't be able to sell a TV from the city in the country side and vice versa. I would be keen to hear what an electrical engineer on hackernews has to say!
Interestingly, when I visited the countryside, I saw some AC electrical appliances. One elder couple had an enormous 80ies style stereo-set gathering dust in the shed. I was told they were a wedding gift.
Laptops, TVs and other electronics already run from DC. Also, there are a lot of appliances for camper vans, boat which run on 12v or 24v DC. On Alibaba you can buy a stove for a few bucks: https://www.alibaba.com/product-detail/Solar-DC-12V-24V-Batt...
I'm sort of an electrical engineer. Increasingly things don't run directly off 120/240V directly. Anything with a power supply could be designed to run of 48V DC nominal. My slight obsession is that really the world needs a low voltage standard. Things like lighting, low power appliances don't need 120/240V.
I'm with you, and actually bullish on this to be a viable way forward.
48V DC has been eyed already for a potential standard to emerge. Doesn't need massive cables to deliver decent power (4A ~200W). There is enough hardware around coming from use cases like EV and Boats that could make it work. Many battery solutions already 'talk' 48v without lossy stepdown of voltage, etc.
Big plus is that the regulation is A LOT less strict for <48v DC compared to AC 110/220/240.
I worked as an electrical civil engineer for few years.
>> the world needs a low voltage standard
we have high voltage standard because it means we can have low amperage to transit same VA.
Because voltage doesn't kill, amperage does.
It's for safety.
DC is far more safer then AC, but it's not that much safer.
If we convert 20A 240V AC (very bad, you can't move your hands away) to 48V DC we get a wooping 110A (instant death)
But if we convert 20A 120V AC, we'd get 55A 48V DC. It's on the same level and has the same problem with moving your hands away.
My country used 220V (as most do!) so switching to DC would mean huge safety threat, but for 120V countries I'd say – go for it!
Not an electrical engineer, but doesn’t the voltage combined with the bodies resistance dictate the amperage? So anything under 50VDC just can’t transmit enough amps through the body to be harmful?
Interestingly, when I visited the countryside, I saw some AC electrical appliances. One elder couple had an enormous 80ies style stereo-set gathering dust in the shed. I was told they were a wedding gift.