It's apparently been done, but the amount generated was very small and it's not clear it could be scaled up to any useful amounts.

https://spectrum.ieee.org/earths-magnetic-field

Excellent! I like it when experimentalists and technologists prove some significant set of theoreticians wrong!

Interesting read, thank you for finding it.

This seems like a very obvious solution. But of course I am ignorant on electricity generation and or the physics involved. I am hopeful someone will enlighten us.

Really hoping for some better, first-principles or technically comprehensive answers here from the HN hive-mega-mind....sigh. And I wasn't the only one... I reckon nobody gives out expertise for free these days, myself included, so I understand y’all’s reluctance. Double heavy sigh.

The trivial amount of power you can generate is great for nerd sniping[1] , but won't even light a flashlight.

I wouldn't expect a lot of discussion about it.

[1] https://xkcd.com/356/

Hmm, I'm not sure that's true. The 30cm Zn-something tube generates mcirovolts (1e-6), but you can imagine longer, and more, such tubes. With volume (width x depth x height) you can quickly scale up to 1000s of volts or more.

THat's just 1 experiment!

On the other hand, there is thermal heat radiating up from the ground, and during daytime, up to a full kilowatt per square meter of solar illumination. Both of which dwarf this effect.

We've been nerd sniped ;-)

I guarantee my goal was not to nerd snipe HN. It's just such a huge amount of power, a giant spinning iron core, a planet sized magnetic field. Hmmm, I still feel there's a way to get more power than we expect out of that geomagnetic technically instead of the micro power from that Zn tube, imagine something like an AA battery's worth, but the size of a red-bull can.

Anyway, my next idea is what about tapping the Earth-Sun coupling. This is not "solar PV" territory, but rather the energy that the sun dumps into the Earth that is channeled through the field and produces effects like auroras, particle cascades.

The crazy thing is, this is an enormous amount of energy:

- 10–100 GW quiet, up to 1–10 TW (or more) in big storms.

It's global, but concentrated by field lines into ring-shaped auroral ovals over the poles. Would be cool if there was a way to tap it. It doesn't need daylight, unlike solar. It's constant, and 10-100x more in solar storms. Crazy power. Would be very cool to tap.

Yep... I've been at that same thought...[1]

The ionosphere can be modulated, which is what HAARP proved. Back when Tesla was doing stuff, a Gigawatt seemed like unlimited power, now... not so much.

[1] https://news.ycombinator.com/item?id=27469542

This is great! I really like this thread nexus we had. Do you have any idea about what would happen if you could do that? Tesla seemingly created some anomalous effects. Anyway, what a fascinating tangent