4 ms·

Trolleybus is a technology from over 100 year ago.

kube-system 2y ago
Yes, but a primary advantage to private transportation is the ability to drive it in locations other than predefined routes in dense city centers.
- elihu 2y ago
  I think the point they were making is that a suitable technology to deliver power to a moving vehicle has been around a long time, not that everyone should get rid of their cars and use trolleys. If we combine a modern EV with 100 year old tram technology, you get the ability for a car to charge itself when travelling on roads that have a compatible system of overhead power lines. Having a huge pantograph on top of the car is kind of impractical, but powering cars from underneath via power rails embedded in slots in the road, like a full-sized version of those toy slot cars that used to be popular, is another option that's been tried on some roads in Sweden.
  - kube-system 2y ago
    My point is that those solutions are impractical for any sort of widespread use.
    - elihu 2y ago
      Impractical compared to what? The U.S. burns about 4 million barrels of gasoline and about the same amount of diesel per day, mostly just pushing ground vehicles around. That sort of works, but I wouldn't call it practical in the long run. Converting to EVs is the obvious alternative, but batteries are expensive and we haven't scaled up battery manufacturing yet to the degree necessary to replace ICE vehicles. We can get more EVs on the road though if the average EV can get by with a much smaller battery. On some level it's an optimization problem: using the U.S. as an example, there are about 280 million cars/trucks currently registered. Is it cheaper/better to build about 280 million EVs with about 60kwh of batteries each on average, or build 280 million EVs with about 30kwh of batteries each and electrify our major highways? If batteries cost $100/kwh, then 280 million * $100 * 30 = 840 billion dollars. If electrifying the major highways can be done for under $840 billion dollars, then it makes sense to do. The interstate highway system is about 50,000 miles. Sweden spent about a million euros per kilometer to electrify a section of road using the slot-embedded-in-the-road system. That's about $1.7 million per mile, or $86.5 billion. You'd probably need to do more than just the interstates, but then at the same time you don't need to electrify 100% of the length of those highways. Maybe just 10% or 20%, as long as electrified section come at regular intervals. This is all kind of simplistic and hand-wavey, but it seems like it passes the threshold of "we should at least consider doing this."
      - kube-system 2y ago
        > Impractical compared to what? The U.S. burns about 4 million barrels of gasoline and about the same amount of diesel per day, mostly just pushing ground vehicles around. That sort of works, but I wouldn't call it practical in the long run. Maybe you mean it isn't 'sustainable'? ICE vehicles are the epitome of practical, they are used in practice all around the world. > You'd probably need to do more than just the interstates, but then at the same time you don't need to electrify 100% of the length of those highways. Maybe just 10% or 20%, The people who developed that project estimated they'd need to implement it on 25% of all roads. Also the project is just in a technical demonstrator phase. It is literally just a tech demo, and there are still major concerns about adoption, implementation, and maintenance. > This is all kind of simplistic and hand-wavey, but it seems like it passes the threshold of "we should at least consider doing this." I agree it should be tested further, but there are likely significant barriers that will prevent it from being useful, particularly in less dense areas.
- skjoldr 2y ago
  The focus of the effort to make overhead charging viable is on large trucks that already drive mostly, but not completely, predefined routes on highways and in cities, which are often too lengthy to only rely on battery packs.
  - kube-system 2y ago
    Others up above were discussing passenger vehicles. For trucks on the highway, it is a much better idea, but for many of those cases, you'd be significantly better off investing in more rail.
    - skjoldr 2y ago
      Transporting refrigerated goods over moderate distances and last-mile delivery from the train yards are where trucks using overhead cables can shine. I also read that there existed trolleybus lines that went several miles/kilometers between towns that weren't connected by rail. It's especially useful in mountainous terrain.

Yes, but a primary advantage to private transportation is the ability to drive it in locations other than predefined routes in dense city centers.

elihu 2y ago
I think the point they were making is that a suitable technology to deliver power to a moving vehicle has been around a long time, not that everyone should get rid of their cars and use trolleys. If we combine a modern EV with 100 year old tram technology, you get the ability for a car to charge itself when travelling on roads that have a compatible system of overhead power lines. Having a huge pantograph on top of the car is kind of impractical, but powering cars from underneath via power rails embedded in slots in the road, like a full-sized version of those toy slot cars that used to be popular, is another option that's been tried on some roads in Sweden.
- kube-system 2y ago
  My point is that those solutions are impractical for any sort of widespread use.
  - elihu 2y ago
    Impractical compared to what? The U.S. burns about 4 million barrels of gasoline and about the same amount of diesel per day, mostly just pushing ground vehicles around. That sort of works, but I wouldn't call it practical in the long run. Converting to EVs is the obvious alternative, but batteries are expensive and we haven't scaled up battery manufacturing yet to the degree necessary to replace ICE vehicles. We can get more EVs on the road though if the average EV can get by with a much smaller battery. On some level it's an optimization problem: using the U.S. as an example, there are about 280 million cars/trucks currently registered. Is it cheaper/better to build about 280 million EVs with about 60kwh of batteries each on average, or build 280 million EVs with about 30kwh of batteries each and electrify our major highways? If batteries cost $100/kwh, then 280 million * $100 * 30 = 840 billion dollars. If electrifying the major highways can be done for under $840 billion dollars, then it makes sense to do. The interstate highway system is about 50,000 miles. Sweden spent about a million euros per kilometer to electrify a section of road using the slot-embedded-in-the-road system. That's about $1.7 million per mile, or $86.5 billion. You'd probably need to do more than just the interstates, but then at the same time you don't need to electrify 100% of the length of those highways. Maybe just 10% or 20%, as long as electrified section come at regular intervals. This is all kind of simplistic and hand-wavey, but it seems like it passes the threshold of "we should at least consider doing this."
    - kube-system 2y ago
      > Impractical compared to what? The U.S. burns about 4 million barrels of gasoline and about the same amount of diesel per day, mostly just pushing ground vehicles around. That sort of works, but I wouldn't call it practical in the long run. Maybe you mean it isn't 'sustainable'? ICE vehicles are the epitome of practical, they are used in practice all around the world. > You'd probably need to do more than just the interstates, but then at the same time you don't need to electrify 100% of the length of those highways. Maybe just 10% or 20%, The people who developed that project estimated they'd need to implement it on 25% of all roads. Also the project is just in a technical demonstrator phase. It is literally just a tech demo, and there are still major concerns about adoption, implementation, and maintenance. > This is all kind of simplistic and hand-wavey, but it seems like it passes the threshold of "we should at least consider doing this." I agree it should be tested further, but there are likely significant barriers that will prevent it from being useful, particularly in less dense areas.
skjoldr 2y ago
The focus of the effort to make overhead charging viable is on large trucks that already drive mostly, but not completely, predefined routes on highways and in cities, which are often too lengthy to only rely on battery packs.
- kube-system 2y ago
  Others up above were discussing passenger vehicles. For trucks on the highway, it is a much better idea, but for many of those cases, you'd be significantly better off investing in more rail.
  - skjoldr 2y ago
    Transporting refrigerated goods over moderate distances and last-mile delivery from the train yards are where trucks using overhead cables can shine. I also read that there existed trolleybus lines that went several miles/kilometers between towns that weren't connected by rail. It's especially useful in mountainous terrain.