“We Dodged the Apocalypse”
A CME will be far from the apocaplypse, even one 100 times bigger than the Carrington event.
The physics of a CME and how it impacts our technology are a bit of a technical deep dive, but I’ll do my best.
A CME is not like an “EMP” of Hollywood. A CME will not impact your electronics, it will not keep your car from starting. It’s possible to minimize damage from it.
The reason the telegraph stations of 1867 caught fire - or in some case continued to function despite being disconnected from their battery banks is complicated, but here’s why it manifested like that back in the day.
A CME impacts the earth when the charged particles from the sun hit our geomagnetic field - and “move” them. When you move the geomagnetic field you generate a very low-frequency circulating current in the earth - it may travel hundreds of miles beneath the surface. The net effect on the grid is that the ground potential at a particular geographic location may change relative to another location on the earth.
If you have telegraph stations that may be hundreds of miles apart - a “quasi-DC” current will flow (basically very low frequency - a fraction of a hertz) - and it could be a substantial current. So if this current dumps into a battery station - it exceeds the capacity of the batteries and generate a voltage that may spark and create fires. That’s what happened in 1867.
Today, if you have two transmission substations that are hundreds, even thousands of miles apart, a current will also flow from a substation where the ground potential is high, to where the ground potential is low. This, too, could be a substantial current.
How this causes damage is when a particular type of transformer (commonly in use in the grid) called an “autotransformer” conducts the DC current through its windings - offsetting the magnetic core around which windings surround asymmetrically - and being precisely engineered devices - this causes problems. One half of a sine wave may be unaffected, but the other half goes into “saturation” due to the magnetic core offset. This causes an abrupt “clipping” of the sine wave - and that means it creates harmonics on the power grid, and dumps a percentage of the sine wave as heat in the core.
Transmission lines carry a lot of power. A transformer may normally operate at a very high efficiency. When it is in “half-cycle saturation” it will operate at a much much lower efficiency - and the difference gets dumped into the core which is not designed to dissipate this much heat. This heat builds up quickly and can quickly damage the transformer, even set it ablaze.
That’s a significant problem, but it’s not an “electronics-destroying EMP”.
However, not every transmission substation will be subject to this impact. Today, things like “GIC” (the DC current on a transmission line during a CME event) can be monitored. It can be blocked if one puts measures in in advance. It can also be shut off, if one monitors it closely, as we are able to do now.
The other impact of a CME is to satellites. One way satellite operators respond to a CME is to align the satellites solar panels so they are “edge on” to the CME to protect them from degradation and damage from charged particles. Unfortunately this is the worst-case for generating power for the satellite - so unless they have sufficient battery power, they will quickly have to go into a “power save” mode. This is one reason why GPS gets interrupted during a CME, as well as other satellite communications.
One other communications-related impact is with undersea cables. High-speed communications rely on fiber-optic relays. For undersea cables, these have to be powered. Usually on both ends of a cable. These ends are obviously thousands of miles apart - so if the end points (or any relays/repeaters along the way) have a difference in ground potential, it is possible to cause damage to an undersea cable, if it is not properly designed to protect against this.
So let’s look at the worst case for a CME: Some power transmission substations may be damaged. Some transformers attached to power generation stations may be damaged. Some satellite services will be disrupted for a period of time. Some undersea cables may be damaged.
Given that some warning will be given due to continuous monitoring of the sun and solar flare activity, there is a good chance we will be able to respond before a CME hits the earth. There are lots of potential responses - and some are likely to be disruptive, but we can avoid the worst long-term consequences if we are willing to take those actions.
Bad? Yeah, probably. Apocalyptic? Probably not if we are not stupid about it.
The complicating problem is that the bits of infrastructure at risk to damage from such are expensive, not rapidly replaced and we don’t stock enough spares for them. So what does get broken stays broken for awhile. I’ve read for years, from knowledgeable folks like you, that quite a bit can be done to harden the grid and mitigate the risk. And that satellites offer enough warning time if the fixes are done properly. However, and I’d be delighted to be wrong and corrected on this, to the best of my knowledge our politicians and regulatory authorities continue to act stupid and neither mandate nor fund the needed changes. They’d far rather waste larger sums on greenie wind and solar nonsense. The worst of them think any natural event killing lots of humans desirable. And outside of the developed world there is currently little of even considering the needed fixes. Whomever manages to sidestep this will be rebooting a lot of the world that didn’t for some time. Praying that random CME aim leaves us enough time to over the stupidity of our elites.
Excellent explanation. Thank you. One question: How will solar panels and solar farms be impacted by a massive CME? My limited understanding is that solar farms may experience severe damage.
Uh, in other words we are doomed.
(Kidding, sort of...) Just for reference, how much induced voltage can a 100x Carrington CME create in a wire 100 ft. long? I've seen induced voltage from lightning do some pretty interesting things even though the current was quite low. Granted that such damage usually involved small semiconductor junctions, both conventional and FETs.