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Houston-area residents enter sixth day without power, air conditioning

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Re: Houston-area residents enter sixth day without power, air conditioning

#91

Earlier quoted context omitted.

Increased trimming of trees near power lines. Apparently CenterPoint spent significantly less than some of the other power suppliers on maintenance. I don't know that it would help in this specific instance, but connecting Texas to the rest of the power grid would likely make the system overall more resilient.

It wouldn't have helped. Trimming trees is preventative maintenance so that simple wind gusts don't trip lines when branches encroach on power lines. The only way you can prevent damage from falling trees is to completely remove them.

Then it might be necessary to remove or relocate the trees since Houston is so vulnerable to hurricanes.

Re: Houston-area residents enter sixth day without power, air conditioning

#92
post #24

Earlier quoted context omitted.

What's wrong with below-ground power distribution for metropolitan areas?

Nothing, but migrating to it is very expensive. Centerpoint, the physical electricity provider in Houston, has said it would cost $2.5M per square mile. Houston is 640 square miles. Regulations allow them to claw back costs on the bills. (For example, repairs from past storms are often paid for over the course of several years in the form of a bond that is applied to customers as surcharges) https://www.houstonchroni…

Penny-wise, pound foolish. This single 1 week power outage is going to cost Houston a lot more than $1.6B.

Re: Houston-area residents enter sixth day without power, air conditioning

#93

Earlier quoted context omitted.

This wasn't a "grid issue." It is a last-mile issue. It's specifically an issue with the sheer amount of above ground power lines and population density. There is no easy fix, preparation, or practically anything else that can be done to prevent something like this. Plus, what causes the same amount of power outages (wind damage) isn't going to be different between 90mph winds and 150 mph winds. The effects are going…

I don't think the difference between the power grid and the power utility is clear to most people. The grid is a statewide wholesale electricity distribution network which consists of generators, substations and high voltage long distance transmission lines. The utility is in charge of taking the power from the grid and delivering 110/220V to end customers, i.e. homes and businesses. This hurricane caused a lot of da…

> The utility is in charge of taking the power from the grid and delivering 110/220V to end customers, i.e. homes and businesses.

Sorry to be pedantic, but most US businesses have 208/120V or 480/277V three-phase electrical services. There are some old existing 240/120V three-phase high-leg delta (aka bastard leg) delta services. [0] Delta-wye transformers are the most common type today, that’s where you get the 208/120 and 480/277 services from. [1]

Larger commercial/industrial customers can have their own medium/high voltage substations and premises wiring/distribution.

Medium voltage is 2.4kV to 70kV with 4160V and 13800V being the most common for commercial/industrial applications. High voltage is roughly 100kV to 1mV.

[0] https://en.m.wikipedia.org/wiki/High-leg_delta

[1] https://en.m.wikipedia.org/wiki/Delta-wye_transformer

Re: Houston-area residents enter sixth day without power, air conditioning

#94

I was there last weekend & for the day of the hurricane. This was just a cat 1 hurricane at the time it passed through Houston, and there was SO much damage. I can't imagine the city is remotely prepared for (god forbid, and idk how likely it is that far inland anyway) a cat 4 or 5. We were staying in a hotel that had a backup generator, but every single other building that was visible from our hotel had lost power d…

I’ve lived through a lot of big hurricanes. Cat 1 storms can be worse than more intense storms, as they are often slower-moving, so they can dump a LOT more water per square inch. Not sure if that was the case here, but it doesn’t necessarily mean they’d fare significantly worse under higher category storms.

Re: Houston-area residents enter sixth day without power, air conditioning

#95

Earlier quoted context omitted.

"no easy fix, preparation, or practically anything else that can be done to prevent something like this" Regulations on the initial construction? In other words, plan ahead. But no, I must have my 'Freeeeedooooommmmm'. You can't force me to prepare.

Why didn’t we think to regulate physics before!?

Closer to regulating that providers of essential infrastructure acknowledge that physics exists.

Re: Houston-area residents enter sixth day without power, air conditioning

#96
post #24

Earlier quoted context omitted.

What's wrong with below-ground power distribution for metropolitan areas?

I’m not an electrical or civil eng, but I imagine it’s very expensive to dig so many tunnels. Groundwater (especially for coastal cities) and people drilling holes would be very problematic too.

"not an electrical or civil eng. So let me explain how impossible everything is that I don't know about, and snidely say it's just 'physics'".

Re: Houston-area residents enter sixth day without power, air conditioning

#97
post #31

Earlier quoted context omitted.

Houston is gigantic. Maintaining underground infrastructure can be very difficult. https://practical.engineering/blog/2021/9/16/repairing-under...

Berlin, 3.645M citizen, everything underground. Houston, 2.302M citizen, ... "gigantic"

As I understand it, the topsoil in parts of Texas is only a foot deep or less and then it's solid bedrock. This is why most homes do not have basements.

Re: Houston-area residents enter sixth day without power, air conditioning

#98
post #31

Earlier quoted context omitted.

Houston is gigantic. Maintaining underground infrastructure can be very difficult. https://practical.engineering/blog/2021/9/16/repairing-under...

Berlin, 3.645M citizen, everything underground. Houston, 2.302M citizen, ... "gigantic"

Berlin, Germany is inland, with an elevation average around 34 meters above sea level. The ground soil composition in Berlin is primarily sandy, draining easily and lending itself exceptionally well to underground infrastructure development.

Houston, Texas, is coastal and has an elevation that averages around 13 meters above sea level. The ground composition in Houston is primarily made up of clay. Houston soil is notoriously heavy and has issues with drainage in construction. It's poorly suited for underground infrastructure development.

Re: Houston-area residents enter sixth day without power, air conditioning

#99
post #24

Earlier quoted context omitted.

What's wrong with below-ground power distribution for metropolitan areas?

New Orleans and Houston are basically built on swamps. In New Orleans, you can’t even bury people below ground, so I doubt you can do much with power lines underground.

It turns out we don't need to speculate:

https://www.sciencebase.gov/catalog/item/64650dded34ec179a83...

Most of the wells they sampled are > 100 ft above the water table. Some are as low as 12. The lowest is 2.83ft. Here's the relevant bit of the schema XML document for the CSV the produced:

   
     DTW23
     
        December 2022 through March 2023 depth to groundwater in feet measured
        from land-surface elevation referenced to NAVD 88
     
     U.S. Geological Survey
     
       
         2.83
         453.97
         feet
       
     
   

Re: Houston-area residents enter sixth day without power, air conditioning

#100
post #24

Earlier quoted context omitted.

What's wrong with below-ground power distribution for metropolitan areas?

There's nothing wrong with it. But it would take lifetimes of money and time to retrofit a city like Houston to move all power infrastructure underground. And there is no way consumers would ever sign up for the cost to do so. It would be akin to building the Hoover Dam today. It would probably be one of the largest public works projects ever attempted.

Lifetimes of money, really? What is that measurement? Someone above said 2.5 million per square miles. Catastrophic damage from larger storms is often in the tens to hundreds of billions of dollars, so it feel like it would be in the best interest of most parties to embark on this project, even if it happens slowly.
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