📺Nebula comes free with a year of Curiosity Stream (for only $15/year!): https://curiositystream.com/practicalengineering 📚Looking for a great holiday gift idea? My new book is now available everywhere: https://practical.engineering/book

@10:32 "...disrupts Earth's gravity..." wait...what? Is that true? Do solar storms disrupt the gravity of Earth?

Lol, a 'smile diagram'... someone has a sick sense of humor 😆

@Mr. Bulldops No, it's a script error. Sorry about that. I have a correction in the video description.

@Practical Engineering could you point me to some resources about non-nuclear EMP's? I want to avoid popsci BS that most search engines are flooded with.

Grady, AM radio antennas are usually located nearer to the ground than FM antennas. The broadcast signal from an AM antenna can result in structures such as cranes becoming charged, resulting in high voltage, low current arcing. One of the oil tankers in our fleet reported that at a certain dock they experienced getting shocks when putting slings on the crane hook. The crew discovered if you held a small fluorescent bulb near the crane hook you could get it to light, Uncle Fester style. We found that there was an AM radio antenna nearby that was used occasionally by a radio station. When in use at the same time the ship's crane was being used the crane would become charged. In checking with commercial crane operators, this was a known phenomenon. One operator told us that they had issues when working on San Francisco Bay. It took some time, and a solution was worked out with the refinery, radio station and new safety practices for crane use on our ships. Oddly enough I probably was 30 years into my career before this problem was ever encountered. Bob

Why they put the highway guard rails in , we had to reduce power. Worker were getting rf burns!

your comment made me extremely happy, thank you ethan

But is your name Robert or Bob?

@MD yes: Bob is short for Robert.

Thank you Bob. Arvid

I'm a retired electron pusher. I started as a microwave radio tech in the USAF (honor graduate Keesler AFB 04/1978). Over a 40+ year career, I moved from RF Tech to Engineering Tech to Design Engineer to PCB Layout Engineer to Senior EE with a major defense contractor. In fact I worked as a contractor since 1996, wearing many hats and mostly in aerospace and military design. Consequently, I have worked at times intimately with EMP and as SI (Signal integrity) oversight for an engineering department developing large integrated circuit test systems. My favorites were spacecraft and satellite design. The space environment is pretty unforgiving, and those devices typically cannot be brought back for repair. They have to function in the harsh environment of space. Your video was an excellent overview. My only comment is that the study you referenced specified a 1 megaton HEMP (high altitude EMP) detonation. That sounds a bit like hunting moose with a .22 rifle. In a tactical situation intended to disrupt, say, the United States, I would expect at least a 10 MT if not 20 MT device, and possibly more than one, e.g. one over the Appalachians at a latitude between ew York and Washington; oneover central Texas, and one over the Sierras on a latitude between San Francisco and LA. This would hit major population and technology centers while taking down all three major grids: NS along the East Coast, EW across Texas and the south-eastern US, and NS along the West Coast. As for the solar induced equivalent, we are actually overdue, statistically speaking, for another 1859 Carrington Event level solar CME (coronal mass ejection) impact. That one burned telegraph wires in two and set operators' equipment on fire, which was the most advanced electrical technology at the time. We just missed an even larger CME by less than 2 weeks in our orbit in 2012. It would have been a technology killshot. As you stated, the fast E1 pulse would couple into virtually all conductors, even the smallest, inducing spikes in the traces on integrated circuit (IC) silicon dies. We briefly discussed this in an IC Fabrication course I took around 2002. The copper traces on a printed circuit board (PCB), where components are typically mounted and interconnected, are also ready made antennas for the E1 pulse. I focused on PCB layout and signal issues for about 18 years of my career. The E2 period does indeed have many characteristics like lighting, and many lightening arrestors should handle it. The E3 pulse is another matter. In EMP and HEMP situations it is able to induce ground currents. In a solar CME induced planetary scale EMP, these could be significant, dwarfing the regular man-made HEMP. These are the currents most likely to destroy large grid regulating transformers and even generators. They can travel into electrical loops by a "sneak path", using the ground connection to enter electronics not designed with a robust power connection, and traveling "up" to the power source (normally the input power). Needless to say, a reverse current of high magnitude would be devastating to most equipment. I _DO NOT_ have experience in large scale power distribution, "The Grid", but warnings I have read indicate it, too, could be susceptible to such high reverse currents. Add this to the directly coupling E1 pulse, and there could be significant current and high voltage spikes tnduced into the windings in both transformers and generators. These transformers and generators are not off the shelf components, as the video stated. These are custom built OVERSEAS. In a worldwide event like the solar-induced EMP, it is very unlikely these will be replaced soon... if ever. Consider the events in New Orleans in the two (2) weeks following Hurricane Katrina. Once it became apparent that services like electricity, phones, and water were not going to be immediately restored, the social structure began to crumble. When it became known that supply trucks were not going to be able to resupply the supermarkets, the normal "three days of food on the shelves without resupply" was stripped in TWO HOURS. I also have a degree in psychology, and human dynamics in events like this are one of my areas of interest. One of my best friends had family in the area in Baton Rouge, and they experienced predatory behavior escalate as well. Given a probable loss of the power system due to Grid failure, collapse of the financial system due to loss of the communication system - no internet means no banking system, loss of transportation for food resupply, and loss of refrigeration for existing food storage AND medicines, and the situation in many urban areas will probably be much worse than the few weeks following Hurricane Katrina. Don't forget that no communication, no transportation (gas pumps run on electricity even if the vehicles' computers were not fried), and totally dark cities at night means no police or other order enforcing bodies. It could become very dire very quickly. Read _One Second After_ for a fictional depiction of a small town following an HEMP event written by an expert in EMP. This book was given to congressional members when a bill to harden the electrical grid was under consideration. My thoughts about that book were expressed exactly by the Naval Captain that wrote the epolog: I would love to have been able to read this as a work of science fiction, but I knew all too well that everything portrayed was entirely possible.

Last year I came across a couple of 100% foreign Chinese. Male and female. 52 miles to the closest town outside of Weed, California. They were stuck in a Mercedes RV. Spoke no English. Dressed like they were stuck in the early 80s and had alot of what looked like camera equipment and black boxes that had Chinese writing on it. The woman didn't speak. I'm not kidding when I tell you the guy made my hair stand up. Not friendly and demanded help...and "right now". Maybe he didn't know how he was coming off. But NONE OF IT MADE ANY SENSE. It has me wondering now. Were they "mapping" ?

Gee, I wonder if a country like, say, China could send over a weather balloon carrying an EMP generator.

I thank you for your accurate synopsis. I've spent my career as an electrical technician for one of the worlds largest steel companies. I would say that 80-90% of our hv transformers and electric motors are custom built per application, and probably the same for most of Americas infastructure building companies. I believe an EMP type event would probably be far more destabilizing than a localized nuclear event. I'd guess longstanding mutually assured destruction rules out the latter. An EMP would take us back to a pre-industrialized civilization for those able to make it long enough to avoid the horrors Mankind will do to itself until predation and starvation have killed most of us off. As a practicing Christian, I would rather a nuke fall on my house than to live through a nationwide EMP event. Hurricane Katrina would look like an afternoon thunderstorm compared to that. God Bless

In 2014 I was in an electrical maintenance program at my local college and one day I asked one of my instructors how long we could survive a widespread power outage. His answer: one month, yes...two months, no. It was sobering to realize we're only one massive solar storm away from utter catastrophe.

after three days, anarchy.

The practical reality is that a Carrington ++ event is overdue relative to the 12k year solar cycle. Sadly, even placing all electronic equipment within Faraday cages won't shield them from that event. No cellphones, no efi engines (no vehicle transportation), no power, no ac... P.S. forgot to mention : no power - no clean water, no medical care beyond first responder first aid.

The phrase is '9 meals from chaos'.....Day 1 without food you're hungry , Day 2 your desperate, Day 3 you'll do anything to get what you want/need.

@Endlesspath at least electronics can be recycled, rebuilt, or repaired.

Less than that, I call 3 days before folks, you know those folks, go nuts! See, agree, 9 meals, 3 days 👍

Additional notes about transformers: Even small substation transformers cost $MM's. Additionally, they're often custom-sized specific to the substation they are installed at and the lines they are tied to. Manufacturers make them to order and they often have multi-year order-to-deliver dates. Even repairing a transformer can take over a year.

Would you know if it is possible to rewind them rather than replacing them entirely? I've had to rewind burned out transformers in old audio equipment where no replacement exists and/or the value of the item I'm repairing depends on everything being 'stock'. If these big substation transformers burn up, is the damage limited to the windings or does take out the laminates as well?

@Killing Masheen Rewinding is certainly possible, though it's a pretty long and complex process. If the protective relays trip fast enough to prevent damage beyond the coils, rewinding would be a faster alternative to building a brand new transformer

You really should do a little googling, about how electrical high voltage transformers work, and how they are made.. We still have the means to make them here in the US, the only reason most are made overseas, is due to labor costs..

I got a tour of a Coast Guard station once and the final thing they showed us was standing next to their thousand foot antenna was holding a fluorescent light up near it and the light lit up. They also showed us where some protesters jumped the fence surrounding the antenna (plus the fence surrounding the Army base it was part of), anyway, they spray painted on the concrete base of the antenna. That person came within inches of becoming a very crispy critter because of the amount of amps that was in that antenna. Needless to say, we walked away with a heck of a lot more respect for those tower antennas.

5G towers??😳

Not 5G, if it’s a Coast Guard station it’s most likely either short wave radio, a M radio or UHF/VHF radio which is commonly used in the marine sector.

You can do the same thing under high voltage transmission towers. The field is immense, also do not park your car under transmission lines for any amount of time. When you try to get into your car you can get shocked from the induced current.

Woah it lit up a 40 watt bulb. Lol

Part of my job is to plan the installation of industrial equipment. Currently the delivery of simple high current power panels has a delivery time of over a year. Before the problems caused by the Virus the delivery time was 2-4 weeks. Small 32KV @ 100A transformer lead times went from 3 month to 2 years. Larger transformers right now have a delivery time of up to 5 years. And it gets worse. A EMP that not only takes out transformers but also the distribution centers, communications and the internet will cause civilization as we know it to disintegrate. Civilization is only skin deep and people will behave in a way that will destroy society.

“A nuclear detonation is unwelcome in nearly every circumstance” is the understatement of a lifetime 😂 Great video Grady, really enjoyed learning about this!

Unless you need to breach the Shield Wall mountain range to approach Arrakeen

nukes were used to seal some gas wells in the soviet union.

A low yield nuclear detonation is quite common every time you eat a taco.

@AlexDRockhound think that falls under nearly every circumstance

Unless you're a South Asian nationalist

This topic reminds me of a book I read titled, "One Second After" that is a fictionalized story about 3 EMPs in this manner detonated to cover the entirety of the United States. It sounds like from your description in this video, the total damage in a real life scenario wouldn't be as bad as detailed in the book, but the book provides a good frame of reference for some downstream effects of a world without power, specifically on communications, logistics, and especially healthcare and the social ramifications of suddenly finding ourselves in this situation without preparation.

Great book! I’m halfway done the second right now “One Year After”

I read that too. Good book that puts in perspective how reliant we are on everything electronic from medical to cars, phones and computers, etc., but if all that failed, we’d be set back 200 years! Worst case scenario book, of course, but it makes you want to be prepared for any disaster, natural or otherwise.

Except that real EMP doesn't work the way the book describes, thankfully.

@Railgap Esoterica maybe. But it depends on distance, intensity as well as other factors. (That I didn’t understand)

Plus in the book, two of the three detonated over North America. This video is only talking about one detonation. Great trilogy of books. I’ve loved them all.

As a kid, around 1950, I saw a live telecast of a nuclear explosion in Nevada. The TV microwave relay system had been built that far west by then. The countdown reached zero and then the picture broke up because an EMP took the camera off-air. But it took only a few seconds and some good whacks to get a picture of the mushroom cloud on the air. Vacuum tube electronics is much more resilient.

✍️✍️✍️✍️🤳🏿

I used to work for a defence contractor producing military avionics [military radios for military aircraft], and we used to test for EMP in our military radios... and I remember the test set was able to generate a pulse with a 1KV peak in a 1ns rise time. This is a lot faster than lightning, which is typically 1KV peak, with a 1 microsecond. This is the EMP spec that we used for testing our avionics systems, as we had special test rigs for testing the effects of EMP. The power supply rails, such as the 5 Volt rail, had special zener diodes that would short out the power supply rails, and was designed to detect the gamma ray flux. It would create a short glitch for the radio, but protect against surges that might occur. In fact we tested a muzzle velocity radar unit, by putting it into a reactor, and the protection circuits worked. In addition that filter connector that connect to the radio system also had special EMP filters to protect the avionics.

The grid might not be protected, but I'm sure all our military installations are hardened to one degree or another.

Thanks for putting this out. I've been correcting people about EMPs for years and it is frustrating to not have a source that is fairly definitive while also keeping it simple enough for the average person to understand. I spent a lot of time reading through the papers available on this. Some were difficult to find. I'll be interested in what source material you found and your future videos on this subject. Well done so far.

✍️✍️✍️✍️🤳🏿

I hope you was telling them an emp wepon does not exist, i keep asking for a emp test video, not seen one. An emp from a nuclear weapon does not count.

@aeroflopper Nearly all videos today are from digital cameras. Digital cameras are digital, and have electronic components in them. EMPs fry electronics. So unless you are standing really far away and/or have the camera EMP shielded, the EMP will destroy the camera. This also destroys the video. Someone could use film instead so it doesn't get fried, but unless you get some expensive, modern film, the video quality would be bad. You are asking for a recording of something that would destroy most direct recordings. You would be better off asking someone how they felt after a nuke was dropped on them; there are five people who lived fine after it.

I had no idea the Navy did testing like this. My grandfather was a part of the LCS for the Boxer and had many stories to tell, and it’s awesome to stumble upon one of the things he assisted with

That is what the Navy and military do other than fighting of course

They did a lot....You didn't want to be a sheep then...

My Dad was on USS Boxer and stated he was on the deck in 50’s. He offered he helped with ‘catch and release’ and now I wonder of ‘what’. He worked in a wind tunnel and eventually balloon projects with NACA/NASA to progressing to senior leadership.

@Kaushik Bala My father worked at naval research lab working on satellites. I tried every way I could to get him to tell me about what he did. I talked to him in his sleep to get him to tell me. I mean I'm your daughter you can tell me.. But not a word.

As an electrician, I have been involved in a lot of interesting construction projects. My favorite and most memorable one was an entire building that was built with EMP shielding. Just like an MRI room. It was a building to house the control center of a major city’s grid control. It looked very much like your footage of the grid control center in this video. I think you could do an entire long-form video about the engineering that goes into MRI rooms. They have copper walls and EM filters and wave guides. They can be huge or fairly small. The world-renowned company ETS-Lindgren is one that has done all the shielded rooms and buildings I’ve ever seen. They’ve done secret projects but also lots of health-care projects.

That does sound interesting. ✌️😎

Sadly, that is the exception. When I worked in the microwave center (later obsoleted by fiber) of the electric utility that employed me, we had a crew in to do a TEMPEST review of the facility. I never was told the result - no need to know - but it was obvious we were a sitting duck.

that would make a very interesting video! maybe a collab with Colin Furze haha

Sounds a lot like a certain energy company’s room in Virginia that I’m aware of, really wild stuff though.

We built one for the Air Force and just used 3/16th steel with filters and waveguides.

Living in a hurricane area, I see how crazy people get after just a few days with no power…and this is an area we expect to lose power…or should. Imagine weeks/months for large regional areas.

Yup. And year after year, our population grows more emotionally dependent on electric service and internet continuity.  Public reaction to service outages in my city is markedly more animated than during the Katrina/Ike era.

And with no help coming.

Blackouts (from storms) do not happen often here, not today anyway, but I can remember some longer ones from few years ago, like a few days blackout, and nobody cared, it was inconvenience at best, so maybe it depends on area/country.

Thanks! My 95 year old uncle was heavily involved in the 1950s, conducting research on electromagnetic radiation releases for our government was more than curious concerning the yield of the Soviet nuclear detonations made at the time. Still secretive, my uncle mainly discussed the primitive conditions of his accommodations in the Pacific and Alaskan areas; than the study of electromagnetic pulses. Great video.

You should hear the 'growling' that comes from a step-up transformer during a solar magnetic event. We monitor temperatures and ground current much more frequently during such a storm. Great video!

You make some incredibly thorough, highly educational videos. I just discovered this channel and I must say, I love it!

Great video, as usual, Grady! After your explanation of the grid protections, and reading MG50's great comment below, it sounds like the E1 pulse would toast the delicate electronics and relays designed to signal and protect the slower/more mechanical protections built into the grid, leaving them unprotected. Then the E2 and E3 could really "fry the bacon", leaving us in camping mode.

Man, these Election Day ads are getting out of hand. Now I don't know which EMP plan to vote for! 🤣

I want to know why I turned off personalized ads and do not share location but I still get local re-election ads

Vote for the EMP that gives a 4th grader a school lunch instead of the one that makes them carry a pregnancy to full term.

@David Hold even with location services off it will try to generalize to an area like the state. Edit: Personalized ads are using cookies and browsing history, if anything I’d think you’d get less political ads with them on

This is why I pay for premium. It's worth $12/month to not be patronized as if I'm a severely intellectually disabled toddler!

Vote for EMP 42 - They guarantee equal destruction for all electronics!

Grady, you deserve an award for your work. Awesome quality, absolutely no bias, wonderfully presented. Will subscribe to curiosity stream today. Thank-you!

✍️✍️✍️🤳🏿

I love your videos so much! I'm really a huge fan. Although this is a bit different from your normal videos this is still right up my alley. Electricity and EMR is so interesting and fascinating. Likewise I'm always keeping my eye out for infrastructure around me. Because of you I actually know so much more about my surroundings which I was always so curious about. Thanks for taking the time to share your passion with others, it has impacted my life in a good way. Thanks and have a good one.

Thanks for this very accessible education. I’m very interested in the complex relationships you explain. The curated slides and graphs you find and show are equally revelatory of the underlying principles. I really enjoyed this episode!

I once used a vandegraf generator to build up a surface charge across a bunch of my students holding hands and standing on desks to insulate them, when we discharged the person-circuit, it caused the television in the room to turn off and was not able to turn back on immediately. Wasn't able to reproduce that day but we had a fun few days of discussion afterwards

awsome

Tesla coils are awesome too!

Very interesting, informative and worthwhile video. I would be helpful if you did a video on how to protect personal devices ( smart phones, tablets, flash drives, walkie-talkies) from an EMP and a CME. Do Faraday bags offer sufficient protection? Many thanks.

VERY surprised you didn't mention 1962's Starfish Prime (1.5MT) which was over Johnston Atoll and it's subsequent EMP knocked out power and phones here in Hawaii for at least a few hours. Hawaii is nearly 900 miles away. Some LEO satellites also got knocked out because of it. It's a perfect answer to the videos question and a literal what would happen in the real world.

Exactly. People running for public office should have to talk about these subjects.

I was about to say that too about the Hawaii event for that high altitude nuclear test then. If I remember correctly the Soviets experienced the same thing for few of their nuclear tests as their over their own territory.

The reason it's not mentioned is that the claims you made about Starfish are either wrong or exaggerated. It blew a few streetlights (and the claim is not certain) and damaged a microwave link between islands.

@kylesenior Think it was a little more than that..

Ever since the EMP problem has entered popular discussion, I've wondered why the lightning arresters on the grid couldn't handle it. Thank you for answering that question for me. Of course lightning arresters aren't perfect either. They do occasionally short to ground. I saw this at the manufacturing plant where I'm working now. We had lost a phase of incoming power, and we called the power company. A lineman came, and quickly identified that a clamp had burned through, and had come off the line. He put a new clamp on, and reconnected it. He was instantly encased in a ball of light. Then everything went dark. After a few moments, I asked, "Hey man, are you okay?" He responded with a dejected sounding, "Yeah. But I'm going to have a HELL of a sunburn in the morning." What we didn't consider was the reason the clamp burned through to start with. The lightning arrester had shorted, creating a huge current path that overloaded the clamp capacity. He didn't have a new arrester, so we just disconnected it so the plant could get running again, and we scheduled the replacement for the next day the plant was down for maintenance.

This is the most electronically technical thing I've seen on YouTube on this subject. As an electronics technician, I loved it. 1 mega ton is very small, and 200 miles is very high. That is above most low earth orbiting satellites. So an actual nuke would be way worse than he was discussing.😳

I had a lightning bolt strike my apartment building. I don't think it hit any mains supply as nothing tripped - but one corner of my living room had basically everything fried. I later learned that is where the lightning rod's ground wire was routed, so it seems the EMP induced from that line caused an overload in appliances within about 3m (10 feet) of that corner, including my amplifier, television and a digital clock.

Sounds like an origin story to me. You should start testing yourself for superpowers, immediately. Good luck...Lightning bolt Liam! ⚡and Use your power wisely.

In addition to being concerned about grid protection devices being susceptible to EMPs, I also think about the effects of faults due to the (unknown, but possibly large) number of improperly configured protection devices in service now. We won't know they're wrong until they're needed.

Here in Sydney Australia our electricity grid will be terminated from the EMP. It’s exactly how you detail it. Having worked on the transmission network the electronic circuit protection will be fried. Most cities around the world have underground transmission networks because the overhead transmission towers and corridors take up too much real estate. Anyway these underground cables run optic fibres within the cable to act as a thermocouple to monitor the temperature of the conductor. The temperature is directly proportional to the load. Anyway to save the cable from burning out under high load the circuit relays will trip the transmission feeder. All this protection equipment is controlled from a central control room and is massively vulnerable to an EMP. Just a side note that when it came to privatisation of the electricity grid, the NSW government used to own it, the Chinese offered to buy it. Luckily they realised what if the Chinese had control of the control room, so much easier to destroy that than a nuclear detonation.

You might find this interesting regarding an AM tower. Back in the early 1980s I worked at a radio station and for the AM side of the station, the tower was out behind the building. During storm there would be these pulses that would run through the system such that they would spike the needles on the monitoring needle gauges (old school). I would go outside to look at the tower and you could see and hear electrical pulses running down the guy-wires. It was amazing and scary at the same time. I never knew why it would do that (I'm not an electrical engineer or anything) but I assumed that the air was, like, "charged" from the surrounding storms and that was interacting with the "AM waves" and generating electrical current that was grounding down the guy-wires. Do you think AM towers still do that or do they ground them differently now?

I work on merchant ships and experienced something similar in a large thunderstorm in Colombia recently. Our MF/HF antenna started buzzing, almost a sizzling bacon sound. As soon as lightning would strike somewhere, the sizzling would immediately stop, then start building up again until the next flash. It was daytime but I was wondering if at night St. Elmo's fire would have been visible from the whip antenna

EE here, fundamentally during a lightning storm the clouds and ground form a large capacitor that slowly charges from the turbulence of the cloud mechanically separating charged particles. At the capacitor charges the electric field (measured as Volts per unit distance) also builds until the air itself undergoes dielectric breakdown and the capacitor shorts out in an event called lightning. Your antenna is grounded not to some universal 0 Volts but to the local dirt/ground which is having its voltage changed as its basically the bottom of the capacitor. To broadcast any signal from an antenna fundamentally just means to pump a voltsge wave through it, and this is added onto the natural electric field and when they combine the locally overwhelm the air. For the radar in the ship the bacon sizzling noise is from the radar pulses breaking down the air, but if every pointy part of the ship was crackling that would be the natural field from the storm. (And to my knowledge St Elmo's fire is the name for corona sparks on the rigging of ships by natural fields, i don't know if it applies to corona from the manmade power sources like radar, radios, or even transmission lines which often have corona issues resulting from the extreme voltage used to keep current down)

it is electrostatic induction. Thunder clouds are heavily charged and create strong electric field between the cloud and earth surface, and earth surface charges in response. Every sharp point connected to the ground starts to form corona discharge (if seen, these are called st. Elmo's fire). In strong radio-frequency fields of AM transmitter these torches of corona discharge can produce sounds and you may even hear the sound transmitted by this radiostation.

@Jason Reed what a wonderful explanation. thank you!

@elrond12eleven thank you for the explanation. it was powerful to witness and hear.

Could you follow this up with a video of the effects of a massive CME effects on the grid?

Very nice video! Only one comment I have: you don't saturate the transformer with the doorbell transformer experiment. On the contrary, loading the transformer more will reduce the field strength. The field strength is solely determined by the voltage and frequency of the mains. When loading it resistively, the voltage drop is caused by the resistance of the wires and the leakage inductance of the transformer.

I believe that there were later higher altitude rocket launched tests (starfish prime?) that caused even more issues but to satellites. I think that they even destroyed Telstar 1 accidentally as a result. I imagine that this would be a very early part of any hot exchange and whilst the grid would probably survive comms would be devastated.

Your video does a great job of explaining the effects of a Nuclear EMP. As you stated, the E3 will add a DC component to the AC input to a transformer. If this causes the transformer core to become saturated there will be no back EMF and the current will only be limited by the resistance of the winding. This excessive current will quickly burn out the primary winding of the transformer.

Off Grid TREK in Canada sells a large "Faraday cage" bag for storing sensitive electronic devices you may need in an emergency like radios, smart battery power sources, etc. This bag protects against strong EMPs. They also are most known tor their highly efficient foldable solar "blankets" for use in car camping, RV and home power outage situations with a smart lithium storage battery.

I sincerely appreciate how much attention you pay to pointing out when your demos are just decent conceptual illustrations as opposed to full on science experiments. That nuance gets lost way too often and it’s rad that you’re so careful with that. Great work as always!

how would it affect the power grid in a bad way obviously🤣🤣🤣

My father at the time was on leave from the Australian army and was at his property in northern Queensland here in Australia where I am right now. He built a ham radio broadcast shack which in fact I'm in right now cause its air conditioned and nice and cool. When that nuclear bomb was detonated he was having a conversation with a guy in Guam when suddenly the guys signal was cut for about a minute. Dad noted in his radio book the time and later on he did some research with the help of the Australian army and found out it was the emp that cut his signal. Dad didn't know much about nuclear emp's but he had heard about them and that america was testing out in the bikini atol and the English were testing here in Australia. He also detected the Russian tsar bomb with his radio equipment which I still own now he has passed away. I was on a boat of the coast of Queensland and 200 kms east of the barrier reef when I heard the volcano erupting when the sonic boom was generated

Great Videos Thanks! As a Power Supply Designer for many years, I remember an experienced senior designer when I was fresh out of school told me: "When a transformer core saturates, it's just a piece of wood!"

I bought your book "...Plain Sight": fun and useful reading but perhaps a bit basic for my background. The "Keep an eye out" diagrams are a high point. More would have been welcome as I was hoping for a "guide to weird engineering structures seen from roadways" or something like that.. Overall good work, and thanks!

I did some work several years back with Dr. Peter Pry (electrical engineer, CIA Analyst, and chair of the congressional EMP Commission). The congressional study found that due to the inability to replace key components in a timely manner (there are only two factories left in the world who produce the core super transformers) that an EMP strike would leave us in a blackout nationwide. It would take 18 months to start seeing power restored and 5 years to get power back to 80% of what we have now. The commission estimated that within 12 months 90% of the population would be dead due to starvation, accidents, lack of access to medication, and anarchy.

The EPRI study is a source I've been using for years on educating other amateur radio operators regarding hardening electronics against EMPs. However an EMP is not my fear, a Carrington Event level CME is and is much more likely.

What

@racist man coronal mass ejection aka what happens when the sun farts in your direction. The last time this happened was back when we were still using telegraphs.

@leo nguyen thanks

@leo nguyen xD the sun farts at us

Eyes open, no fear.

This video confirms what I have told people. Warheads like this are virtually unstoppable(without focused energy weapons) because they can detonate in the atmosphere and have far reaching effects. Little did I know they are more potent as well.

I once felt a lightning bolt strike very close to my house. I'm not sure of the exact location it hit but I know it was close because the thunder was louder than the biggest rifle I have ever heard. The lights in my house flickered off for like .1 seconds but strangely enough the only damage I noticed was my ethernet port on my desktop computer never worked again.

I have lighten fry a TV,but when I took the back off it was a fuse,new fuse in just blew again when turn on after 3 trys got the message new t v time. Then another time the controller on my furnace got fried by lightning digital, has to buy a new controller, can't figure out whether lightening really likes me or is somebody trying to tell me something 😬

@Bob Flatman I had 1997 internet until this year when I upgraded to the Elon Musk Starlink but ya my old internet was from telephone lines that were buried in the ground in the 80's so any lightning within 5 miles would cut off the internet.

If it sounded like a rifle crack it was about 2-3 miles away. If it sounded like an explosion and shook the house, it was about 100 yards away, most likely less. You'll never mistake a near strike for a close strike. Where I used to live in central Virginia, it was standard practice to turn off the TV when there was a lot of lightning, about 5 miles away. And when it was really close we unplugged the microwave and the TVs from the wall socket. If youre wondering, yes we did lose a TV and a microwave to a near lightning strike.

Heard of this phenomenon before

I helped publish hundreds of EPRI reports while in SF. They took the job internal though. This reminded me of those days. That is a common California thing, where people worked for a place then became contractors later then later the company took the opportunity back. It was my roommate who actually worked there in person. The PREPRESS days for before the dot come bust.

Small, locally limited, small modular reactors could power just a few neighborhoods and lessen EMP dangers as well as the mammoth time delays and expenses of building and installing mammoth high voltage transmission line transformers. We need a video on the EMT effects on small local power systems.

You should do another video examining the effects of a repeat of the Carrington Event of 1859. As well look at the effects of a larger pulse, because the sun is certainly capable.

I actually had a VERY nearby lighting strike that fried my home router, and my brother's next-door. We had a Cat5 cable connecting our homes, running down the wall and underground. This seems to have acted like an antennae and allowed the EMP generated by the lightning strike to fry both of our home routers connected via that cable!

Oh, and I forgot to mention... we had already shut most of our powered devices and unplugged our computers and TVs. However, we did NOT disconnect our ethernet cables - which includes that one that ran between houses. That's the one that got us, even with no power on to our routers.

@Brian Renken Fiber is the future. 😄

Stealing internet? Nice.

@J N Sounds more like sharing you fool, stealing is the act of taking without permission.

Local storms (50km away) would cause continual problems at some sites. The adoption of fibre optic connections cured this.

Thanks for all of the helpful information. Great job!

Excellent presentation! I just subscribed! Very well broken down to us who are simple laymen.

I'm going to build an anti-EMP cover for my whole house generator. It'll also keep the rain and snow off of it. The question is, is there any other part of my internal electrical system in the house that also needs to be protected? I do have a whole house surge protector if that matters.

Loved the video, I'm totally stoked that you are venturing into a broader range of subjects!

✍️✍️✍️🤳🏿

Even more interesting and of actual practical use for individuals would be a video on what ordinary electronic items EMP would be expected to destroy AND if simple Faraday cage-like structures properly grounded are useful in mitigating EMP. I use steel shipping containers (not junk, buy nothing less than "one trip" grade for shop use!) to house my welding equipment, machine shop and motorcycles because they're far tougher and don't burn like stickbuilt trash but I'm curious if their windowless all-steel shells also mitigate EMP. As a mechanic I've spare vehicle PCMs I store in those anyway and own vintage trucks with carbs and very simple electronic ignitions (with some spare points distributors) but computer survival of equipment not grid connected has me curious. BTW any pre-Twin Cam Harley is easily converted to points ignition in about an hour and being comfy with that extremely simple system I've several bikes so fitted. Simple Fairbanks magnetos still common on vintage agricultural engines and tractors were also fitted to Harleys and the classic Army "Mules" which are undisturbed by EMP like many classic military vehicles. A person with a variety of operable engines can help restore society locally by powering more than just generators. Of immediate importance will be maintaining farm equipment and water supplies. Is it practical for a skilled person to fab a (small, ENCLOSED, grounded) EMP test mockup to observe effects on common devices? Many people own ample land isolated from anything small tests might damage.

Protection and control engineer here - I design the control systems that trip the breakers using the digital relays mentioned in the video. Very informative way to explain this paper to the public, in a much more interesting manner! There are many utilities that are currently buying concrete control houses or having their control houses shielded with elaborate copper shielding systems on critical bulk electric system sites. These approaches (largely) mitigate the issue of E1 pulses affecting the control relays. It's proven much more difficult to prevent damage from the E3 events, as the protective relays we use now won't necessarily detect those conditions and trip everything offline. Furthermore, while your control relays may be shielded from most of the issues, your voltage transformers and current transformers out in the yard will not be as protected. If you can't rely on the data coming into your relays, you can't effectively trip and protect your equipment.

As someone not familiar with these systems, is it possible to shut everything down instantly from the NOC, or would you have to send a truck to every facility to isolate it manually?

@User 2C47 The vast majority of circuit break devices are remote operated and can be done from a central terminal at the utility control center. There would always be some that have to be manually operated, but those are typically more for redirecting power during partial blackouts rather than in order to protect the equipment.

How much more troublesome would a sequence of these events be? If there were say, dozens of overlapping pulses at different times?

Would it be helpful to put distribution points in valleys? Along mountain ranges you could put centers for the westward regions on the east side and vice versa. Up to a certain point it's not worth shielding things I'd guess.

I'd be interested in comparing the effects on HVAC vs HVDC transmission lines.

I’m curious about the affect on cars; comparing a 1993 car compared to a 2003 car and again with a upcoming 2023 vehicle, the difference in the overall effect on the electronics which years would still run after an EMP ? I’m sure the strength and distance of the signal output would make a huge impact on the outcome. Any thoughts about this would be greatly appreciated. Love your work!!

Basically, any vehicle without electronic fuel injection would be fairly safe as long as it was off at the time. Newer vehicles would become very large paperweights.

@Mr Dean that’s kind of what I was thinking I do have a 1993 Chrysler New Yorker salon but I don’t drive it much so I probably won’t be on the road when the EMP hits. Thanks for answering me by the way.

@Davld Bradley No problem. I enjoy answering questions that are logical and well-thought out. Especially when I actually have some information on it 😀

Pretty sure my 69 ford and my ol' lady's 72 nova will be ok except for the radios. Getting gas at pumps that don't work? More difficult.

@woodhonky At the pump, yes. Fairly easy to get from the tank under the station.

When I was a kid I built a small spark gap generator with a vertical antenna about ten feet long. Pretty much jammed am radio around my house for quite a distance so I knocked that off because I didn't want an FCC van showing up and giving me the facts of life. Nowadays with everything having microchips with so little distance between internal junctions an EMP can send computers and communications into the stone age. Don't know if it's true, but the rumor back then was that Russian bombers used tubes to counter this. Scary thoughts.......

geomagnetic storms are a far higher risk to the grid than an EMP, due to the frequencies involved. I want to say modern systems are being shielded from both, after the incident in Canada that caused a huge blackout. Even so, a modern day carrington event would be absolutely disastrous.

✍️✍️🤳🏿

It doesn't sound that bad because his scenario is a 1 kilo-ton device. However, if an adversary has the ability to launch a device at high altitude above the US, they are also likely to have a much larger device. I would say a 1,000 to 10,000 times larger (1 to 10 mega-tons). In the large device scenario, it's certainly lights out for several months. Think of COVID-19 style disruptions times 100,000. During COVID-19 we had electrical power, natural gas, running water, cable TV, internet, cell phone coverage, and clear roadways. With a large-scale device, causing a +1000x EMP event, all the aforementioned infrastructure is down for several months. If it happens during winter, people would starve and freeze. I'm not going to link it in this comment because you can search it yourself. But, there have been multiple studies estimate 80% to 90% of Americans would perish if we just lost the grid for 3 months. We'd basically off eachother.

(Edit) The Carrington event was another example of what happens when DC offsets are applied to the power grid, although back then it affected little more than telegraphs. If such an event were to happen today it could be catastrophic, probably much worse than a nuclear EMP. It's so scary the sun can in theory decide to do stuff like that without warning.

Thankfully it was the biggest one on record and hopefully it doesn't happen again in our lifetimes... But I'd love to see the northern lights!

@Red Sky Ready I mean it's pretty much a given that we will see one in next 30 years or something. Hopefully we will be prepared for it at least somewhat.

It doesn't decide, it just is.

Entirely different mechanisms, though. Here in Arizona we have no problems with CMEs, largely because of the distance from the magnetic pole but partly because our transmission lines are primarily north/south. CMEs are nothing like an E3 pulse - they are prolonged DC currents.

Grady, hypothetically, if everyone suddenly started creating their own DC power and converted their home to strictly run off direct current would this mitigate the harmful effects of an EMP for the average household?

✍️✍️✍️✍️

If you recall, in the first days of Covid, there was a run on toilet paper. How the two are related still eludes me, however, I believe the larger impact on society will be transportation and the availability of food and other resources. Could you follow this up with how an EMP would affect automobiles and trucks, as I believe that loss would be closer tied to societal collapse?

I have been a fleet mechanic for a public utility for the last 17 years. You can see why I find this video and your question fascinating. Before working for the utility, I was a retail mechanic for 23 years. Combined, I have 40 years experience in auto/truck repair. I am not bragging about my experience, rather I am using it to make my point. The advances made in electronic controls of the modern automobile and truck are staggering. Modern cars and trucks have up to ten or more modules that share information across a twisted pair of wires called a CAN/BUS. Taking out just one of those modules can cripple the entire vehicle. Its disturbing to think how easily that can be done. Furthermore, almost all newer cars use satellites to share information between the vehicle and the manufacturer or whoever else is monitoring that information. That communication goes both ways. How do you think OnStar can unlock your car with a simple phone call? Yes, an EMP could indeed cripple the transportation industry. But, I fear that is not the only threat. It wouldn't take much for a gifted hacker to do the same. I have seen more changes in the last 10 years of the modern automobile and truck than the first 30 years combined. Car owners wanted more conveniences, safety, and performance and got what they asked for. Meanwhile the government wanted better fuel economy and emission controls, and got what they wanted. Manufacturers added the ability to monitor their creation to make sure the car owners and feds are happy.

@Randy R yep. I have been looking casually for a distributor ignition vehicle, but old cars are seemingly way more coveted than they were previously, especially four wheel drive units. Those will be even more sought after should this happen. One Second After is a pretty realistic picture of what will happen if a bit dramatized, but anyone who has read it looks at EMPs (or any other kind of grid disruption to your point) a little differently now.

They did a test on cars in the 90's and it wasn't quite as bad as they thought. Most of the cars kept working and the ones that had issues were mostly visual instruments.

I noticed you showed an SEL relay. I worked at SEL as an electrical drafter implementing these relays into the electrical designs of these systems for a short while.

We use more electronics than ever before, but that might not be as big of a problem as it first seems. I've read that while smaller electronics are more vulnerable to spikes, at the same time, modern electronics are more hardened against electromagnetic interference, and their small size means that they'll be less exposed to the waves as well. I think in the end, it may depend on the location of the devices, their quality, and maybe even their orientation if they survive or not. Though let's hope we never have to find out.

Very true for small electronics. On the flip side I hope that the power grid and comm infrastructure with their inherent size susceptibility are designed to be robust enough.

Wait, what? Might be very wrong but I do not believe that ANY electronics are "hardened" against EMP unless specifically designed to be so. Can't imagine that the 5 dollar wall wart has ANY level of "hardening". Might be some EMI shielding around the RF side of some items, that is not "hardened". The US power grid is really about at the breaking point, some states don't even have redundancy with other states...oops, that is just one state. (Not trolling or starting a fight BTW)

@skunked42  a lot of electronics are hardened at the circuit board level for anything that used that. There's a lot more fussing and circuit breakers in most modern electronics now.

@Imjashingyou I've never seen a circuit breaker in a consumer electronic device, and fuses are, if anything, less common than they were fifty years ago (though mainly because we simply need fewer power supplies for modern electronics). Nor do either of these have anything to do with EMP: they are for protection against starting ordinary fires of the sort that anything that generates enough heat can start.

@Curt Sampson  maybe it's just because I'm involved in aviation. But everything has multiple circuit breakers and that's for power surges.

Good video. Just a few minor issues: You mentioned the solar storm affected the earth's gravity, when you actually meant magnetic field. Also, the large switches in the transmission and distribution system are called circuit breakers. Contactors are something else. I suppose you needed to explain the concept with using the word "breaker."

Are there specific nuclear designs that are meant to enhance the magnitude of emp? It seems that stockpiling some of the very large transformers that may need to be replaced should be an integral part of our civil defense planning.

Superb. Simply superb. Such fascinating well researched and well explained content, thank you.

Military derived EMP is difficult -- and little real world data. Additionally, modern electronics are surprisingly resilient. Could it be bad if properly applied; yes - but not nearly as bad as you'd imagine.

✍️✍️✍️✍️

Having found the actual details of such a pulse, I have now made my "Vehicle", EMP "Proof" . . . the unit I bought cost me $350.00, but now I no longer worry about being caught off guard, no matter where I might be, as those around me will. This includes the Police an Fire units around me. .

One critique from a EE. In your Marx Generator experiment, you can see the spark jump to the picture frame. So, the resulting damage is more likely from the high voltage entering the case and not the EMP pulse triggered by the spark.

He kind of hints at that (it's direct injection, a LOT of external charges are injected there). But then he says that this might be "an indication" of what an EMP E1 pulse can do. I contend that when you only have the field itself acting on the electronic structure of the internal components, you probably won't get anything noteworthy in this case. At least as far as published E1 values from nuclear high altitude tests are concerned. The only way the EMP can damage things is by having a large enough antenna to build a voltage difference over which then enters unprotected circuits and fries them. But such circuits tend to have voltage protection on them so I don't think this kind of damage would actually be common.

Literally every electric installation has the housing grounded. This wouldn't even scratch anything of importance.

EMP is hard for even RF jocks to understand. It's VERY hard to explain to the average public without fibbing or over simplifying.

Very curious about how the individual cells in solar panels would fare, would make a huge difference either way.

✍️✍️✍️✍️🤳🏿

Awesome video. It's fascinating how electricity seems to work a lot like water flowing through plumbing. (at least when explaining how it works)

✍️✍️🤳🏿

Would the E1 pulse damage/disable wireless radio devices like cell phones and other cellular based technology? It'd be pretty bad if central communications equipment went offline or were damaged, but if your average cellphone/phone/walkie talkie becomes inoperable the end effect seems like it'd be the same.

Probably. Any antenna connected to an IC (e.g. wifi, Bluetooth, cell) is highly likely to get fried by the “white noise” E1 pulse. It doesn’t take much induced current in these delicate chips to fry them.

Thank you for everything that you do, Grady!

✍️✍️✍️🤳🏿

One factor im surprised you didnt cover in this that I believe we are all curious about is all the computerized equipment on a personal level that would be needed to conduct task such as fixing the things that got messed up on the power grid. Vehicles, service trucks, would the emp fry the sensitive electronics in modern computer controlled vehicles? For those of us still running the classics, would it effect the simple computers of yesteryear for electric ignition. Lastly for those running absolute antiques with points ignition systems, would an emp induce enough current in an ignition coil to wreck it? The classic diesel engines with their purely mechanical injection systems are the only internal combustion engines that i know for certain would still operate if the cranking systems were intact or of mechanical design. Batteries is another curiousity.

At a major company I worked for in 1980, we had in-house courses, one was EMP and SGEMP. Bottom line, big transformers running near capacity can be destroyed by the third stage of an EMP because of the dissipation from a big DC current component. This fella I think is underestimating it.

put a large capacitor at input and output of output transformer, as we all know capacitors stop DC voltage but passes the 60 hz frequency voltage. And from video the transformers are heavily shielded so cannot see emp pulse sneaking into windings

I thought the a huge EMP could harden the wire by sending additional voltage at high amperage that “cooks” the wire thus reducing the cable’s ability to transmit power. So you need to either install a parallel wire to pick up the reduction or replace the wire that got cooled. Is there any validity to this?

Risk from EMP is yet one *more* reason to move to a decentralized, distributed power generation system. I've seen some "mesh" network proposals that could be far more robust against EMP & other threats.

Would it be possible to build a hardened shielded electrical grid? I am assuming that power lines buried under ground would be more resistant to an EMP due to the mass of dirt in between them and the blast. But they would probably be exposed where the connections leave the ground and enter buildings?

AvE turned me on to your channel! I'm so glad he did! I love having information laid out for a dumb redneck to absorb at my own pace! You explain things at the level I can get ahold Thank you for that I'll be supporting your channel Sir!

Great channel! Keep up the good work!

Very informative! How did you calculate the air gap? (for arc)

Your demo with the EM generator and multimeter is very similar to a bizarre flaw I discovered in a multimeter just a few days ago. I was using its continuity testing mode and suddenly it started beeping when I moved it near a printer. The EM waves produced in its power supply were apparently generating enough power in the leads that it mistook them for a closed circuit.

It sounds like that printer isn't anywhere near non-interference compliance

Laser printer I'd wager.

I had a radio from my fire department that I could point at various electrical equipment at work, and it was only 5watt, but I could get power supplies to reset. We were having an issue with a Canadian digital TV station making our motor controllers reset at semi random intervals... we ended up solving it by adding some ferrite cores and looping the communication cables in a zig zag rather than a round loop.

@Naomi Inkjet. Also a microwave. Turns out the multimeter's fuse was blown. Once I replaced it it stopped picking up the interference.

I worked with an Engineer that was at Sandia Labs during some of the underground explosions. They tested EMP and landlines. Repeaters on landlines have metal around them EMP. I think car electronics would be protected also.

When I worked at a Pontiac dealership in the 80's, we had a customer who's car was close to a lightening strike. It came in on the hook, as the electronics in the 6000 were fried. The radio wandered through stations all by itself like there was a ghost inside. Very cool. The insurance company wanted to 'total' the car due to the expense and uncertainty of replacing everything electronic in the car.

A friend of mine was on his way to work when his pickup took a direct strike to his CB antenna. Took out the headlights and windshield wipers and of course det-corded the RG-58 (blowing out the back sliding windows) and smoked the radio good. After about 5 minutes the headlights started working again, it must have tripped some self-resetting breaker for the headlights. This was in the late 90's though and it was an older truck so no modern electronics in there. I suppose if it had happened today it'd be a dead doggie.

@Nathan Fisher Mmm. I wounder what a EV will do getting the zap! Battery fire? Steering lock up? Brakes what are those without electronic stuff? I'm sure EV makers and modern car manufactures have no clue or care about how fragile the systems are.

Very informative! I'm still wondering though could it cause nuclear power plants, tempature regulations to burn out, causing a melt down?

I’ve long wondered about this since reading about it years ago. Thank you for going so in depth on the subject.

This video was fascinating! You have to do a video on the effects on the grid from a Major Solar Storm

The most disastrous effect is the creation of a strong, slowly-varying DC voltage across the long transmission lines, as you mentioned in the video. In such event, along a transmission line, the DC voltage causes the HV transformer to explode and the wires to melt, while the transients disable all the inductive loads. Thank you for the great video, Regards from the UK, Anthony

Actually it is the current that kills the transformers in the way he described, and that is only an issue when run near the maximum current for the line. The transformers are damaged but the lines are not.

Why not guard the transformers with big capacitors ? Essentially just setting up a high pass filter

I heard not long ago, maybe last year, but someone was using a drone with copper wire attached to it to try to disable a substation. Would someone doing something like that actually do a major amount of damage or would it just knock out temporary? If so, would the power companies add some kind of anti drone things? Wouldnt be a bad idea to add that either way if you ask me though.

@WilNeal 801 Think you missed the point.

Man that was a fascinating and well put together presentation.. I feel absolutely paranoid and terrified now lol

1. Given a 3 minute Notice, What would Disconnecting the House Main Breaker from the Grid, and Grounding the Feeder lines? 2. How effective would a Lightning Arrester be at the House main connection? I know typically Spark Gaps, and some types of MOV's are typically used. I suspect disconnecting from the Grid makes this type of arrester 50X more effective.

This was very well done! You help to calm some of the fears that others are screaming about! This was explained very well, and puts me more at ease. Now, what am I going to do with all of these aluminum foil hats?

Aluminum wouldn't help anyway. It needs to be tin foil. 😉 I wouldn't be so quick to toss 'em.

The other problem with that report is as you said they tested based on one megaton. Most devices these days are much larger. Obviously I don't think they're going to re-adapt a tsar bomb, but to assume it'll be confined to device that small is wishful thinking as well.

I think a potentially devastating effect that you didn't mention would be the disruption of synchronization between generator plants. As we learned not too long ago here in Texas, when generators go even slightly out of sync, they are immediately removed from the grid. Otherwise, the out-of-phase energy on the grid working against the phase of the generator would literally tear the dynamo to pieces. And if enough plants go offline, it becomes a gigantic hurdle to restart the entire grid. You have to start each plant one at a time, bring it into sync, then bring it online, and then wait a while for the grid to settle down before you start on the next plant. It was estimated that a shut-down Texas grid would have taken 3 to 6 MONTHS to bring the whole thing back online. And I guess I'm suggesting that an EMP, especially the 3rd type you discuss, could definitely cause the plant breakers to snap, even if the plant isn't actually out of sync, bringing entire grids offline.

I wonder if there is a relationship between the EMP effectiveness at high altitudes and Nikola Tesla's idea of beaming electricity anywhere in the world.

I wish I could talk about Tempest - and what it takes to achieve it. AND it's limitations. Those of you talking about MRI rooms - that type of construction was our TEST chambers for testing Tempest devices in. Given how much solid state gear controls our power grid - just call it "TOAST" for a rather wide radius around a high-altitude nuke, and a cascading failure after that for the rest whatever region got hit (unless it's Texas, then the initial blast effects will probably take down the whole thing).

It's crazy how fragile the electrical grid is