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Comment by krasin | Hacker News Reader

This is a ~400 meters segment; the method is quite lossy due to wireless power transmission and also encumbered with a pending patent. I also suspect that road maintenance will be much more expensive, once there are smarts inside.

A time-proven alternative is to install trolleys on such trucks and put overhead wires, similar to trolleybuses ([1]) or electric trains. It's known to scale to thousand kilometers, easy to service and cheap to install. And the road would remain just dumb asphalt / concrete.

1. https://en.wikipedia.org/wiki/Trolleybus

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That doesn't get VC money and crazy people screaming about it. Boston/Cambridge is full of those and it's a pleasure to be on them but there's no crazy CEO trying to sell it so no one bothers to pay attention to them.

Moscow was a trolleybus capital of the world just recently. I'm still salty that they destroyed it in just a couple of years, replacing with regular buses and a handful of electric ones (which still require a small ICE engine in winter to stay warm, ridiculously enough)

Was there ever a reason given?

I guess same like in Prague when they purged their Trolley buses in 1950s - Gas was cheaper back then. MUCH cheaper.

"electric buses are the future", and "wires are ugly and expensive to maintain". Also trolleybus depots are taking some valuable commercial space at the end of the lines, it's easier to have a bus depot on city outskirts. For most of those trolleybuses with a small battery (semi-autonomous) could be a much, much cheaper and reasonable answer, but I guess someone made a good buck on depot real estate or electric buses or whatever.

Especially with all of the problems they've been having over the last couple of years, I had to double-take when I saw you describe riding the MBTA as "a pleasure"

I understand as someone that must have lived their whole life being served by the MBTA it might not be amazing (its also not amazing by european standards, i definitely rode better stuff in Spain, Portugal, England and other places) but by AMERICAN standards the MBTA is definitely one of the best public transportation systems there are.

I'd recommend you take SEPTA in PHL or use the shitty stuff we have here in Miami and Orlando and you'll be praying to go back to riding the Red Line or even, god forbid, the green line.

I meant it mostly jokingly, and I actually agree with you for the most part, though I do think literally catching on fire multiple times is not so amazing. I grew up riding the MBTA and mostly just lament how it's been mismanaged and saddled with debts, resulting in most of their current problems.

USA’s 4th largest city (Houston) has essentially zero usable public transport. Anything remotely usable a few times per week by more than 5% of the city’s population is amazing by USA standards.

Houston population is 2.2M in the city, 7.2M metro area (most of whom at least regularly spend time in or commute to Houston proper).

Same for here in FL, there’s not a single city with any usable public transportation (other than Disney’s).

Overhead wires on freeways have hight issues when trying to power both cars and allow room for oversized loads. It works for trolleys because you have a full sized buss’s height plus the hight of the pickup bar which allows a lot of room below.

Wireless also has quite a lot going for it from a safety, noise, and maintenance perspectives. If they’re deep enough you could theoretically have a 50+ year lifespan while the road surface above gets replaced multiple times. There’s no metal on metal contact so their quiet, and it’s not like the wires can fall up through the road surface.

Germany installed "eHighways" in 2019 which can let heavy trucks charge from overhead lines. Heavy trucks can't really afford much of a weight penalty for batteries (look up "tesla semi load factor" for a bunch of debunks), but cars for general transport have tons of weight to spare. Skip the cars, just go for the heavy trucks.

https://www.businessinsider.com/germany-opens-first-e-highwa...

Giving up on cars is also giving up on a lot of potential revenue which increases payback periods etc. Considering how much of a chicken and egg problem such a system would face you’d want to maximize the number of vehicles that could use it.

@#1 no reason you can't put a raised collector on the roof of a truck

@#2 yeah nice dream. Ever seen a highway under refurbishment? "Deep enough" to survive those machines means you waste even more energy.

Total fantasy this.

#1 is about cars not trucks. You could stick something physically tall enough but you’d run into serious aerodynamic issues.

#2 There’s wireless charging systems more efficient when using power directly than plugging in and charging an EV’s batteries. (edit with a 9 inch air gap) That’s quite a bit of wiggle room if the goal is indefinite range rather than actually charging cars on the freeway. So yes there’s definitely a trade off of efficiency vs maintenance, but it’s not that big a gap.

This just simply isn’t going to be an efficient, cost effective, or maintainable solution relative to alternatives. We’re also not going to have solar roads for the same reason. Sure take moonshots, but they should make sense from first principles.

People already pay a big premium on electricity rates for high speed charging. At ~98% coil to coil efficiency it’s quite competitive.

Semi’s need ~30kW for unlimited distance with multiple drivers and about half that with a single driver and mandatory rest periods. Cars have significantly lower requirements making this a long way from a moon shot.

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