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Rolling blackouts in California have power experts stumped

nytimes.com

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Re: Rolling blackouts in California have power experts stumped

#51

Post by nanomonkey »

war1025 wrote: post #27
genericone wrote: post #12

Earlier quoted context omitted.

Plenty of businesses are still open, and AC still needs to run to drive out building moisture so that they don't develop mold. Maybe not at human comfort levels, but they still need to run them for the whole building.

> AC still needs to run to drive out building moisture so that they don't develop mold. Serious question: How was this handled in pre-AC times? Is it just an issue because buildings are much better sealed than they used to be, or is there more to it than that?

Older, less insulated buildings, breathe better. The more your home "breathes" the more it transfers heat and humidity to the outside, which defeats most insulation, unless the breathing is done though a heat exchange.

Re: Rolling blackouts in California have power experts stumped

#52

Post by java-man »

qppo wrote: post #23
java-man wrote: post #4

The sooner we switch to solar and grid battery storage, the better. There should be no excuse whatsoever not to do that now. What reasoning is holding us up?

> What reasoning is holding us up? People turn their lights on when the sun goes down, and efficient energy storage is the holy grail. Also fun back of the napkin math with overestimates, if we have a totally efficient Li+ battery with 0.25 kWh/kg energy density, and converted all the world's 40 billion kg of lithium in the crust and oceans to batteries, we'd get roughly 10 TWh of energy storage capacity. Which is en…

Also, we don't have to limit ourselves to lithium. Li makes sense in vahicular applications, but the grid storage could be perfectly fine with Na or any other technology.

Here is, for example, a sodium ion chemistry based on prussian blue:

[0] https://natron.energy/technology/

Re: Rolling blackouts in California have power experts stumped

#53

Post by makomk »

lykr0n wrote: post #33
drak0n1c wrote: post #31

Earlier quoted context omitted.

Anti-fossil fuel mandates imposed by the California legislature is part of the reason there is a shortage of power in various areas. Rushing the transition without enough alternative supply in place is a recipe for further problems. https://www.wsj.com/articles/californias-blackout-warning-11... https://www.forbes.com/sites/michaelshellenberger/2020/08/15...

The article states that there was no such shortage...

There was no such shortage if you only look at instantaneous figures and ignore the fact that a substantial proportion of the grid's generation capacity was in the process of rapidly disappearing due to a predicable daily process called "sunset", as the article does. See my other comment. I suspect the person you're replying to might be right.

Re: Rolling blackouts in California have power experts stumped

#54

Post by Gibbon1 »

war1025 wrote: post #27
genericone wrote: post #12

Earlier quoted context omitted.

Plenty of businesses are still open, and AC still needs to run to drive out building moisture so that they don't develop mold. Maybe not at human comfort levels, but they still need to run them for the whole building.

> AC still needs to run to drive out building moisture so that they don't develop mold. Serious question: How was this handled in pre-AC times? Is it just an issue because buildings are much better sealed than they used to be, or is there more to it than that?

Depends, some climates buildings were moldy.

But old buildings generally aren't even close to air tight. Under those conditions as long as they are heated even a little the humidity is mostly lower than outside. Mean the amount of water in the air as a percent is the same inside and outside. But since it's hotter inside the house the relative humidity is lower. In temperate climates you don't get mold.

It's actually modern air tight houses that have terrible problems with mold. Because they don't breath water vapor builds up inside.

Re: Rolling blackouts in California have power experts stumped

#55

Post by ISL »

etimberg wrote: post #45
ISL wrote: post #40

Earlier quoted context omitted.

How does line-sag lead to increased resistance? My understanding is that the mean-free-path of conduction electrons in even OFHC copper is quite short -- scattering on impurities is the dominant loss mechanism, not the boundaries of the conductor. Is the theory advanced above that the morphology of the wire matters, or is there another mechanism at work?

The resistance is not constant and is in fact a function of temperature [0]. Line sag is a proxy measurement for line temperature, since things expand as they heat up. From [1], most materials have positive alpha coefficients so the resistance increases with temperature. 0. https://en.wikipedia.org/wiki/Electrical_resistivity_and_con... 1. https://www.allaboutcircuits.com/textbook/direct-current/chp...

The statement referred to heating driving sagging, which increased resistance.

The increase of resistance with temperature is well-known -- I was curious if there is some effect that is directly related to the wire sag (changing morphology, somehow-altered surface area/skin-depth, changing kinks at the connections, some subtlety with increased length (cross-sectional area also increases), etc..).

Re: Rolling blackouts in California have power experts stumped

#56

Post by aidenn0 »

robomartin wrote: post #43

I think I can say that our entire neighborhood is up in arms about what's going on with SCE in general. In the last few months people have received bills that amount to 10 to 20 times their usual bill. In our case, with a 13 kW solar array, our usual bill is in the order of $15 per month and has been so for years. Last month our bill was $350 and the prior month $184. We have been sending excess energy to SCE for yea…

We benefitted greatly from SCE raising the TOU-D-A peak rates because we generate net power during those times. It sounds like I'm fortunate to not know anything about CPA though...

Re: Rolling blackouts in California have power experts stumped

#57

Post by Scoundreller »

ISL wrote: post #55
etimberg wrote: post #45

Earlier quoted context omitted.

The resistance is not constant and is in fact a function of temperature [0]. Line sag is a proxy measurement for line temperature, since things expand as they heat up. From [1], most materials have positive alpha coefficients so the resistance increases with temperature. 0. https://en.wikipedia.org/wiki/Electrical_resistivity_and_con... 1. https://www.allaboutcircuits.com/textbook/direct-current/chp...

The statement referred to heating driving sagging, which increased resistance. The increase of resistance with temperature is well-known -- I was curious if there is some effect that is directly related to the wire sag (changing morphology, somehow-altered surface area/skin-depth, changing kinks at the connections, some subtlety with increased length (cross-sectional area also increases), etc..).

My thought is that after each expansion/contraction cycle, contraction is never exactly back to its previous state.

Like bending a piece of metal back and forth, it weakens each time.

Re: Rolling blackouts in California have power experts stumped

#59

Post by eggsnbacon1 »

dtwatljfk wrote: post #19
nimbius wrote: post #3

as someone who apprenticed as a lineman briefly, this isnt at all unexpected. Just because you have generating capacity, does not always mean you have capacity in the duty cycle for your transmission infrastructure. Many substations are older, and were never designed to handle high duty and load during climate-change driven weather events. These substations suffer from underreporting as they often dont have remote mo…

> but because NIMBY groups frequently oppose building or augmenting existing substations. Wild claims related to electromagnetism basically kill the project at every level. Can you elaborate? A substation is about to start construction just across the (narrow) street from my child's elementary school.

the em waves produced by substations induce fear of decreasing home values via an unknown mechanism.

Re: Rolling blackouts in California have power experts stumped

#60

Post by redis_mlc »

shiftpgdn wrote: post #50
YarickR2 wrote: post #41

I wonder what would Tesla owners do during fire-induced blackouts. With wrong combination of returning from long drive to homes without power, and fire hazard warnings, people owning only electrical cars could become trapped really bad. Unfortunately, Teslas are a part of a problem for now, being power hogs .

Most Tesla owners I know keep their cars at 80-90% charge every single day since they have a charger at home. That's enough range to get you 4-5 hours away from any would be wildfires.

Towns in fire areas should have egress plans with a bus fleet available.

The traffic jams at Camp (twice) and Berkeley were silly, yet fatal.

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