How prepared are we for the next giant solar flare?
GIC[0] is a pretty interesting risk factor but popular reporting on it is not great. The posted article has some interesting history on the Carrington event and good details on what CMEs are but falls down on when talking about the risk to the power system.<p>Example: &quot;The power grids of most countries would be completely and effectively leveled. The top way to mitigate the effects of such a flare would be through increased grounding, so that the large currents that would otherwise flow through grid wires would instead flow directly into the Earth. Every time power companies attempt to do this, however, what winds up happening instead is that the conducting substance used for grounding (such as copper) is stolen for its material value.&quot;<p>Power grids would not be &quot;completely leveled&quot;. And &quot;grounding&quot; is not the issue (although yeah, copper theft is a thing). Source[1] states that Hydro-Quebec tripped for over current on long transmission lines. This has nothing to do with inadequate grounding and the solution was to increase the over current settings because the system could handle the induced current. The system was restored in 9 hours. Another event[2] listed resulted in &quot;disturbances&quot; across a large geographic area: a voltage collapse and unusual power flow but not outages.<p>If the induced current was much higher the system would trip off to protect itself while the GIC lasted. This could take a while to recover from if it was a wide spread outage but we&#x27;re not talking a civilization ending event like headlines suggest.<p>What power companies are most concerned about are damaged transformers. Replacement transformers (at transmission levels anyway) are very expensive and have months to years long lead time so if a few get damaged restoration could take a very long time. But we have literature[3][4] that tells us what transformer designs are susceptible to overheating due to GIC. TLDR: Most modern transformers will be fine.<p>What I&#x27;m more concerned about are satellites. I don&#x27;t know how many satellites would be disabled and are at risk of collision. That sounds bad. What critical things rely on satellite infrastructure? GPS seems like a big one. Power systems use GPS timing, in some cases to enable differential current protection. But usually these systems will default to impedance protection on a loss of GPS signal and at any rate the industry is probably moving to terrestrial time sources because of the risk of GPS spoofing anyway.<p>[0] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Geomagnetically_induced_current" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Geomagnetically_induced_curren...</a>
[1] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;March_1989_geomagnetic_storm" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;March_1989_geomagnetic_storm</a>
[2] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Solar_storm_of_August_1972" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Solar_storm_of_August_1972</a>
[3] <a href="https:&#x2F;&#x2F;ieeexplore.ieee.org&#x2F;document&#x2F;6281595" rel="nofollow">https:&#x2F;&#x2F;ieeexplore.ieee.org&#x2F;document&#x2F;6281595</a>
[4] <a href="https:&#x2F;&#x2F;www.pes-psrc.org&#x2F;kb&#x2F;published&#x2F;reports&#x2F;GIC Presentation at PSRC 05 14 2014.pdf" rel="nofollow">https:&#x2F;&#x2F;www.pes-psrc.org&#x2F;kb&#x2F;published&#x2F;reports&#x2F;GIC Presenta...</a><p>Source: I have worked on GIC monitoring systems at a major transmission company. But the opinions expressed are my own, etc, etc.