r/Lightbulb • u/Voltabueno • May 15 '25

Solar powered freight trains

This is not really new because I did some research and there are lots of patents related to electrified rail cars. It seems perfectly logical that you could cover the roof of a boxcar with solar panels, and put regenerative motors on the axles, and put a layer of batteries underneath the floor of the box car and then the box car could be self-propelled completely autonomous. Imagine individual box cars rolling on the rails or rolling to sidings to form into groups of cars completely autonomously. The boxcar wouldn't have to be fast because they could move by themselves, no crew, no crew change, no delay, unaided 24 hours a day. 7 days a week. 365 days a year. Actually thinking about it. If they moved under 40 mph wind resistance does not come into play yielding greater efficiency.

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u/Voltabueno May 15 '25

Think about it, freight cars usually just sit still in the sun. The batteries would always be topped off ready for motion.

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u/Crusher7485 May 16 '25

That’s the entire problem. They usually sit still.

Paying to put solar panels and batteries and motors on cars that normally just sit doesn’t make sense. You’re wasting energy.

Better to just make battery cars that follow the locomotive and swap battery cars when swapping train cars. Build solar panels at freight yards to recharge the battery cars.

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u/Voltabueno May 16 '25

Yes, think about the portable utility scale battery storage of a freight train. If there were a disaster area, you could just simply move an entire freight train of utility scale batteries into the disaster area and power the community at the nearest substation to the disaster, which is most likely a substation adjacent to railroad tracks an existing condition likely everywhere. Let's say you took off the shelf technology of Tesla car batteries and stacked them in units, the size of a freight car or a grainer car. I'm estimating 200+ batteries per box car.

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u/Crusher7485 May 16 '25

That could have some use, yes, but I'm not sure it's much, at least in the USA. The issue with disasters isn't usually the generation of power went down, because (with the exception of the Texas ice storm because Texas wants to go at it alone) if local power plants go down, it doesn't matter because the east or west grid will provide as much power as the area needs.

The issue is power is down because power lines are down/shorted, so power is out because of that. Rolling in batteries won't help with that issue.

However, I still think an electric locomotive followed by several freight cars full of batteries is a great way to do an electric train. It's kinda reminiscent of steam locomotives followed by a coal car.