It doesn't work out economically because big networks of usb devices (ie. Hubs) all need the power components if one is to maintain the generalisability of being able to plug anything into the grid anywhere.

https://www.cisco.com/c/en/us/solutions/enterprise-networks/...

Imho a totally crazy waste of expensive gear, but whatever floats your boat...

Hard to go up in voltage as its now no longer considered "low" voltage wiring and hard to go up in current without increasing conductor size of ethernet cable.

The existing limitation is with the 2x23 AWG (or 4x23 AWG) of Cat5e/6/6a not providing a lot of current-carrying capability at a safe voltage.

There is a good opportunity for a startup IMHO.

With 100W PoE, one can daisy-chain 10 light bulbs on one cable (or put them on different pairs of wires within one cat6 cable).

But what I really wanted is controllable devices, so that I could re-assign lights<->switches in my home hub.

UPDATE: and you don't need an electrician license to work with low voltage.

Not quite.

It mentions the asymmetric Neutral current, and this is because in a balanced multiphase system, there is (almost) no current flowing on the neutral conductor, i.e. if you are consuming 10 amps from L1, 10 amps from L2, and 10 amps from L3, then there are zero amps flowing on Neutral. This is also why inherently-perfectly-balanced multi-phase loads (e.g. 3-phase motors with identical phase windings) can be constructed such that they do not require a Neutral connection at all.

In the UK for example it's quite common that houses only get connected up to one of the phases, so if you have 60 houses on a street, 20 each would be connected to only L1, only L2, and only L3. This achieves a reasonable balance in practice; the current flowing on the street's Neutral conductor(s) is/are very small in comparison to the currents on the Line conductors.

As in, it is already fairly well balanced, and there is nothing to be done in this regard.

Within the single-phase installation the currents on Line and Neutral are of course equal under fault-free conditions (typically up to 100 amps for a residential installation). There's nothing you can do to reduce that.

A lot of countries in mainland Europe wire up residential properties to all 3 phases (with much smaller permitted supply currents; I've seen as low as 20-amp main supply fuses), but again they go to some degree of effort to balance their phases with respect to single-phase loads. This is for grid stability reasons.

For the street example again, they could have wired up every house identically, but connected the phases in a round-robin fashion, such that the socket outlet circuit(s) are on a different phase in each house, and so on. If there were ever a severe imbalance (which would be detected automatically, or by routine maintenance and inspection of distribution transformers, depending upon how bad it is), typically it would be arranged for some rebalancing work to be performed, for example by disconnecting an outgoing feeder line serving some dozen properties or more and rotating their phases (connecting the old outgoing L1 to the transformer's L2 output, L2 to L3, L3 to L1). This still maintains the phase rotation order (very important for 3-phase loads, like some EVSEs and motors) but allows a more equal distribution of loads.

See https://docs.openenergymonitor.org/electricity-monitoring/ac... for why this is important.

This is somewhat simplified though. Real-world loads vary their consumption dramatically, and also feature reactive components that shift the current forward or backward with respect to the voltage. A 10-amp capacitive load on L1 and L2 will not cancel out a 10-amp resistive load on L3. Harmonics are also a problem, as the article mentions.