The company I worked for was the same, But it's a curse though. Always got the feeling of being looked down on for not running that gauntlet. If you're being assimilated into the Mountain View Googleplex -- fine, it's so massive nobody will care or notice. But being borged into a small site everyone will know and there were snotty people who openly grumbled about it.
Soooo much of the Ego of Google engineering -- at least in the past -- is built around their sense of superiority of having made it through that interview and being selected as one of the "best engineers in the world."
Gave me heightened impostor syndrome for 10 years.
Indeed, passing data from the secondary to the primary of the transformers is actually hard, adding the handling of voltage transient spikes would make it even more expensive. And you need only a handful of bytes per hour (assuming nice reporting per each hour) - real data is likely fewer than 16bytes (id-time-value), adding an iv and block size encryption is all it takes.
There are powerline carrier (PLC) systems that can communicate over the distribution system at about 1-2 baud. They’re getting replaced by mesh RF systems since PLC is quite lossy and the bandwidth is not sufficient for pulling back full timeseries data for planning studies. I’ve heard PLC systems outside the US work quite a bit better since 230V distribution has fewer distribution transformers.
The US systems are 120 V line-to-neutral (ground), whereas the European and lots of other countries are 230 V line-to-neutral. So after going through a distribution transformer, the non-US systems are at a higher voltage, which means you can distribute the power further without large losses. This leads to more neighborhood-level transformers serving dozens of consumers instead of the US practice of using split-phase transformers to serve only 2 consumers at a time.
PLC-enabled smart meters ("Linky") are the norm in France. I am pretty sure I also heard multiple times that PLC was used to transmit some data to equipment along high-voltage lines.
Yeah, I think PLC is awesome, but it's also just a whole parallel technology stack that has to be maintained and supplied. This is not such a heavy burden because it's mature technology, but it's not nothing. And while cellular and RF technologies in general are useful for many things, PLC is really only useful for this one kind of (lossy, high-latency, low-bandwidth) communication about electrical networks.
Yes, it would be great if there were reliable publicly accessible RF networks available. I work mostly with rural US utilities and the problems they see with cell networks are (1) coverage isn't great and (2) costs aren't competitive with PLC or even utility-owned RF mesh.
Yeah that makes sense. But my general point is that it often makes some sense to invest in a technology that is in the process of being deployed more widely, rather than a technology that is naturally limited in reach. Cell (and satellite) coverage is likely to broaden and move down the cost curve, PLC won't ever be used for anything besides this, and likely isn't going to see much innovation because of that relatively small target market.
A sibling comment makes the more relevant point about powerline, but it’s worth considering that whatever the power company has to pay, you the consumer will be paying for in the end.
You could make the case (a good one I think) that a homeowner providing connectivity should get a discount to their bill, or that the power company could directly charge for a separate communication channel.
That’s kinda saying the same thing in different ways and depending on your point of view they might not feel fair perhaps. But the consumer is paying either way.
Edit: “separate communication channel” could include a human meter reader too!
I was talking about the power cables. But wifi would do the trick too, but as you say why should the homeowner subsidize. It is not so much the cost (maybe 1c of connection) but the onus to keep it up at all times and the security concern of letting IoT you can't patch yourself on your network.
The comms module is normally separate from , but attached to, the electricity meter. Not user replaceable though.
Slightly surprised (act, not really) that this is happening. Seems to have been dodged in Scotland & the North because cellular coverage there was poor enough they went with a 400mhz network instead.
As an electrician we used to pig conduits 50mm-200mm in diameter by wrapping rope around a bunch or commercial rags and tightly duct taping the middle of the pig. The head and tail would then compress to the diameter of the conduit and would be flexible enough to go around tight bends. Very effective
