elihu

...or to open the door of someone else's car if you're a passenger.

No, I think the idea is it backfeeds into everything connected by the same wire -- unless the grid shuts down entirely and there's no 60-cycle signal to synchronize to, in which case it shuts down for safety.

Maybe a useful mental model is a trampoline? The grid is like a jumping elephant or something (I don't know if they jump, we'll say they do for the sake of the analogy), and you could have people also jumping on the trampoline. If they're a bit late, the elephant launches them in the air, and if they're a bit early the elephant sucks the energy out of their jump, but that energy makes the elephant jump higher. And a fully distributed grid would be one where there is no elephant, just a million people jumping on a trampoline.

Wouldn't all three being plugged in be likely to trip the breaker, because it's just AC and the breaker can't really tell whether energy is flowing "forwards" or "backwards"?

Seems like the worst case scenario is when you mix solar panels with load on the same circuit.

800W at 110v is about 7 amps. Suppose you have a 7 amp solar inverter plugged in as the first thing on that circuit. Further down the line, you have 22 amps worth of load. The circuit breaker sees 15 amps, but the wiring between the panel and the load is carrying 22 amps, which would ordinarily trip the breaker but it doesn't because the solar setup is masking it.

I'm not an electrician. Perhaps wiring code has enough safety margin that being 800 watts over on some circuit isn't actually a serious safety concern, but I could understand why this might not be allowed.

The EU is on 230v, so maybe it's a bit more practical over there because you can add twice the solar capacity for the same amount of additional current you'd have in the US, so they aren't eating into the safety margin quite as much. Though it seems they also use thinner wire gauge generally, so maybe the difference is moot.

Having good technical tools won't fix a failing society, but they're still nice to have and they make state surveillance of its citizens just a little bit harder. I mean, where would we be without strong cryptography?

The way I look at it is that a manager can make decisions with wider scope, but the people under them exert greater control in day-to-day tasks over some narrower scope. In software development, for example, a manager might set goals for some project, but it's individual developers who are actually writing the code that usually have the most leeway to decide for themselves how best to solve some particular problem. (So long as it's within the bounds of what peer reviewers will accept.)

I think org charts would better fit how I think of the organizations they represent if they were drawn upside-down, like a tree.

It's the most common unit for describing the explosive yield of a nuclear weapon. So, it's a lot smaller than the bombs dropped on Japan in WWII, but a lot bigger than a Davy Crockett. That's a sort-of-useful frame of reference.

The only other things I can think of that would create a similar kind of blast are a volcanic eruption or something like that fertilizer explosion in Beirut in 2020 (~1100 tons TNT equivalent.)

The Super Turcano is a prop-driven aircraft that's often suggested for this role.

Or, alternatively, you switch to DC to get more current capacity over existing wires. (At a given voltage, a wire can generally carry more DC current because it doesn't have the same "skin effect" that AC has.) Even if the hardware at the substation is more expensive, it might be cheaper than upgrading the transmission lines.

I've been wondering for awhile about the economics of the AC vs DC grid thing. Historically, AC made a lot more sense because transformers are simple and relatively straightforward to make. But now we have amazing capabilities to handle enormous amounts of power with modern IGBTs and similar power-switching transistors. (A modern high-end EV motor controller, for instance, might be able to handle a megawatt of power. Not continuously, but still.) Is a DC-DC converter now more economically viable than an equivalent transformer? The former is more techincally complicated, but the latter is bulky and requires large quantities of expensive input materials like copper.

I really want the US to get on board with solar in general. Parking lot solar is a good thing generally, but I don't think it should be mandatory because it's an inefficient use of resources. We don't have any shortage of rural land.

Maybe a more flexible policy could be something like: for every parking spot, you must add 1 kw of solar somewhere on your property (whether that's the parking lot or building roof or whatever is up to you) or add 2 kw of solar somewhere within a 20 miles of the site or add 3kw of solar somewhere in the US.

A lot of companies might find that the last option is the cheapest, and if that's the case we should want and encourage them to do that instead.

It can be either AC or DC. Aluminum TIG welding uses AC, whereas you'd use electrode-negative DC for steel or copper. As I understand it, with aluminum you need the electrode-negative part of the waveform to transfer heat to the work piece, but you need the electrode-positive part of the waveform to clear out the crud that accumulates in the electrode-negative part. Often you set a lopsided duty cycle and use different frequencies depending on how deep you want the weld to penetrate.

If you go to 100% electrode positive you tend to heat the metal rather poorly, but can turn the end of your tungsten electrode into a molten blob -- which is usually not desirable.

It may be a boon to EV makers everywhere including in China, but I don't think it's a boon to China generally as they buy a lot of their oil from the Gulf states. Thus they're more directly affected by the Hormuz shutdown than the US (which is a net oil exporter and is mostly only affected indirectly by price increases).

Like the Ukraine war, maybe one good thing thing we can say about this terrible situation is that it may encourage a lot of countries to move to renewables (or nuclear) sooner than they otherwise would and cut back on fossil fuels.

The energy crises of the 1970s caused people to start caring a lot more about fuel economy. Now we have the technology for people not to need to buy gas to propel their vehicle at all, and many of them once they switch they're never switching back.

That's true enough at the level of individual households. If the whole neighborhood switches to EVs, the power grid in general might not be built to handle it.

(Personally I don't expect this will be that big a deal, since switching to EVs is something that happens one household at a time over many years. So, it shouldn't come as a sudden shock, and its something the utilities can make long term plans about. It just means power utilities need to be on the ball about not putting off infrastructure upgrades, and it means somewhat higher electricity prices for residential customers.)