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Just what practical options are currently available? With roof-mounted solar panels becoming commonplace (at least where I live) it seems like 12V DC is a pract

Just what practical options are currently available? With roof-mounted solar panels becoming commonplace (at least where I live) it seems like 12V DC is a practical target, but it irks me that it gets converted to AC before being reconverted back to DC by a wall wart a few meters away.

ars 11y ago
80V DC might work, but 12V DC means the wires would be far too thick to be practical. In the past you needed AC for the ability to have transformers. These days you can do that in other ways. But you still need a high voltage, meaning you still need that wall wart.
wklauss 11y ago
That's the problem, there are not many (some fridges designed to be operated from car plugs, camping gear, things like that) and often is just an appliance that has a converter inside, so it is as inefficient as you'd expect. Not sure if there's a way to design stoves, fridges, ovens and washing machines powerful enough just using DC, though.
- mindslight 11y ago
  For stoves/ovens, just up it to 240V DC. They're just big resistors and will work basically the same (although mechanical power switches will wear out quicker, and now that I think more, triac-based ones may not turn off at all). Things could get really interesting if say the EU started incorporating a requirement for things that should essentially run fine on DC to compatible with DC. Universal power supplies (computers, phone chargers, etc) and brushless motors (washing machines) should really only require tweaks of their control circuits. AC motors (fridges/dryers/air conditioners) and microwaves wouldn't be an easy change. They'd either need a local converter or for demand to ramp up for explicit DC versions. Standby power supplies (the thing that powers the IR receiver and power button while your TV is "off") wouldn't function as-is, since the common method is to use a capacitor+zener across the power line. But changing that to a rectifier + small switcher doesn't seem terribly onerous.
marcosdumay 11y ago
Well, 12V is really wasteful. Placing an inverter in the loop is probably cheaper and more efficient than routing 12V electricity though one's house.

ars 11y ago

80V DC might work, but 12V DC means the wires would be far too thick to be practical. In the past you needed AC for the ability to have transformers. These days you can do that in other ways. But you still need a high voltage, meaning you still need that wall wart.

wklauss 11y ago

That's the problem, there are not many (some fridges designed to be operated from car plugs, camping gear, things like that) and often is just an appliance that has a converter inside, so it is as inefficient as you'd expect. Not sure if there's a way to design stoves, fridges, ovens and washing machines powerful enough just using DC, though.

mindslight 11y ago
For stoves/ovens, just up it to 240V DC. They're just big resistors and will work basically the same (although mechanical power switches will wear out quicker, and now that I think more, triac-based ones may not turn off at all). Things could get really interesting if say the EU started incorporating a requirement for things that should essentially run fine on DC to compatible with DC. Universal power supplies (computers, phone chargers, etc) and brushless motors (washing machines) should really only require tweaks of their control circuits. AC motors (fridges/dryers/air conditioners) and microwaves wouldn't be an easy change. They'd either need a local converter or for demand to ramp up for explicit DC versions. Standby power supplies (the thing that powers the IR receiver and power button while your TV is "off") wouldn't function as-is, since the common method is to use a capacitor+zener across the power line. But changing that to a rectifier + small switcher doesn't seem terribly onerous.

marcosdumay 11y ago

Well, 12V is really wasteful. Placing an inverter in the loop is probably cheaper and more efficient than routing 12V electricity though one's house.