13 ms·

- "In 2022, we don't want to go faster" Yes we do! - "the goal instead is high speed trains that accommodate more people" No; we want legroom. - "...while c

- "In 2022, we don't want to go faster" Yes we do! - "the goal instead is high speed trains that accommodate more people" No; we want legroom. - "...while consuming less energy" We don't want that either. Isn't your electricity nuclear power anyway? What's the problem with consuming too much clean energy? You're in direct competition with airline travel, so every bit of increased consumer attractiveness is a *net social benefit* with regards to climate change. What exactly is the hangup? Smells like cost-cutting MBA's shoving through unpopular changes, with a sugarcoating of social responsibility. This future sucks. I want my atomic flying cars back.

progval 4y ago
> Isn't your electricity nuclear power anyway? What's the problem with consuming too much clean energy? According to a 2019 poll, 69% of French people believe that nuclear "contributes to producing CO2 and climate change". (34% answered "a lot", 35% "a little", 13% "not really", 17% "no") Source: https://www.bva-group.com/sondages/francais-nucleaire-sondage-bva-orano/ https://www.bva-group.com/sondages/francais-nucleaire-sondag...
- pasabagi 4y ago
  Well, it does. Nuclear plants have very high embodied carbon, as they're made out of large amounts of steel and concrete. That's obviously not as bad as a coal plant or even a gas plant. But 'a lot' is still probably correct.
  - tremon 4y ago
    By that reasoning, a wind park isn't carbon-free electricity either. I wish you good luck on your campaign to convince the public, after that you can come back here and we'll talk again.
    - cinntaile 4y ago
      If we just look at how much CO2 something produces when it's ready-built we potentially ignore a huge part of the pollution. You usually do a life cycle analysis (LCA) and come up with a g CO2-equivalents/kWh. No energy source has 0g/kWh.
      - Schroedingersat 4y ago
        Not to defend nuclear, but it's competitive with solar on that front and better than anything but hydro. Keeping existing nuclear on as long as it's safe is a pretty clear win climate-wise
  - triceratops 4y ago
    Can a nuclear plant produce enough energy to capture all the carbon emitted in its construction? While still being profitable, obviously.
    - pasabagi 4y ago
      Just thinking the problem through, I think that's very unlikely, unless you're in a pathological situation. So, for a nuclear plant to be profitable in a competitive market, it needs to produce energy for less than its competitors. If its competitors don't have to pay to capture carbon (through money or output) then they are always going to be cheaper per watt, and the plant is going to become unprofitable. The only way that would work is if you had chronic electricity undersupply (v. likely but also pathological) or if nuclear plants were way more efficient than alternatives (the opposite is true). Generally the argument for nuclear is you need a diverse range of energy sources to have a stable power supply, not that they are a great 'bang-for-buck' option. (An argument I agree with, fwiw). EDIT, PS: It's worth keeping in mind that carbon capture is largely an unsolved technical problem, and I think it's perfectly feasible that it will never be solved. The basic idea of burning fossil fuels for energy, then using energy to recoup the carbon from the atmosphere, just makes no sense at all. There's no world where this would be cheaper than just not releasing the CO2 in the first place.
      - DuskStar 4y ago
        If you made all the alternatives also pay to capture their carbon cost, I think nuclear would be very competitive. Obviously it blows fossil fuels out of the water, but hydroelectric also uses huge amounts of concrete, and IIRC the energy return on investment (MWh you get out per MWh it takes to construct) for solar and wind is quite poor and so I'd expect that to take a while to pay off too.
        Retric 4y ago
        Nuclear has a vastly worse EROI than grid PV solar. Nuclear lasts longer which somewhat offsets construction costs, but needs a vast workforce continually and a maintenance and power simply to operate. As a sanity check, sub 2c/KWh solar can’t require that much energy simply because energy costs money. Nuclear on the other hand ends up having ~1,000 workers drive somewhere for 50 years which also takes energy, but that’s often ignored. That said, people love to come up with all kinds of irrelevant comparisons using vastly outdated data to make things look worse for solar while ignoring Nuclear’s downsides. For example France’s capacity factor fell below 70% when they tried to ramp up production and things would look even worse on a 100% nuclear grid.
  - cinntaile 4y ago
    Over their 40+ years lifetime it becomes negligible.
    - pasabagi 4y ago
      Maybe? Because climate change is a self-feeding cycle, releasing large amounts of CO2 early, then amortizing that over decades of operation, is worse than a constant steady release. I guess you're probably right, nonetheless. It just annoys me when people post polls like this to prove that people in general are stupid, when polls generally show that ordinary people everywhere are way better on climate issues than political elites.
      - petre 4y ago
        Concrete absorbs CO2 as it cures. If you add a bit of titanium dioxide it doubles the amount of absorbed CO2.
  - sanp 4y ago
    But that’s sunk cost. That’s not increasing with consumption unless u get to a point where u have to build a new plant.
  - credit_guy 4y ago
    This is incorrect. A large nuclear power plant uses about 200000 cubic meters of concrete. Each m3 of concrete contributes about half a ton of CO2 emissions, so that’s a one time 0.1 MT of CO2 emissions. A coal power plant of similar size will emit more than 1 MT every - single - year. There is simply no comparison.
giraffe_lady 4y ago
Absolutely hearsay here but a family member worked for SNCF as a mechanic for TGV trains (but not the locomotive) and has said that the pantograph was the limiting factor they had designed the last generation around. That it was designed as a wear part and the top and optimal speeds were chosen based on thresholds for unacceptable wear on the transmission lines themselves, which are much more difficult and expensive to replace. He told me never to expect TGV speeds to increase significantly until we saw them ripping out the powerlines and replacing them with an entirely new system. Again I don't know if this is true! But it seems reasonable enough to me. That conversation was about twenty years ago and plenty has changed with TGV in the mean time but sure enough no top speeds have increased on any line in the system in that timeframe, and new lines are deployed with the same speeds as the older ones.
- bombcar 4y ago
  I've often wondered why a wheel rolling against the wire wouldn't be better, after all at those speeds you have a wheel rolling against the track and bearing the weight of the train.
  - pmyteh 4y ago
    Having a low sprung weight is important for pantographs, and getting the 25kV off a rotating contactor would introduce another unhelpful electrical interface I suspect. If you want to know far more than you did before about overhead line electric systems for railways, from a predominantly British perspective, I can strongly recommend Gary Keenor's (free) book: https://archive.org/details/overhead-line-electrification-for-railways-6th-edition https://archive.org/details/overhead-line-electrification-fo...
- crocal 4y ago
  This correct. Power lines wear induced by pantographs is the limiting factor for TGV top speed. The engineer that can solve this problem will allow top speeds in the range of 400/500 kph on /existing/ TGV tracks. Much better problem to solve than hacking a lame hyperloop.
rcMgD2BwE72F 4y ago
Do you know that TGV tickets are very expensive? It's easy to say "faster and larger" when you can afford it. But fitting more people on a train make transportation cheaper for the mass. I'm French and many friends and family would love to take TGV on holidays but have to ride by bus (search "cars Macron") or by ridesharing (Blablacar) due to the TGV prices. SNCF recently re-launched some quite old trains under the low-cost "Ouigo Intercités" brand, because demand for cheap-but-slow transportation is more and more popular. I took one from Nantes to Paris this summer (many hours longer than by TGV) and will prefer it next time too. I could fit my bike for free there (vs 10€ in TGV, where I also usually have to disassemble beforehand).
- Drunk_Engineer 4y ago
  The bus is a much better travel option anyway. Trying to make travel plans with SNCF is a nightmare with their constant strikes.
  - lapinot 4y ago
    In which world is the bus not a nightmare?! Waiting for it at a random bus parking where nobody knows where it arrives, almost no ability to walk around nor go to the bathroom, less space than train, no access to your big luggage.. I'm not even talking about speed or efficiency.
    - mumumu 4y ago
      Most buses on Europe have gps tracking and updated timetable available online, they are also fairly comfortable.
      - yakshaving_jgt 4y ago
        Most? Can I see the data? I'm imagining you and I exist in parallel Europes.
        4y ago
rospaya 4y ago
> Yes we do! Speed is limited with infrastructure, and France isn't exactly the US. There are not a lot of population centers like Germany which has 14 cities that have more than 500k people while France has four and 20% of the population lives around Paris anyway. You can get from the center of Paris to the center of Marseille (second largest city, other side of the country) in about three hours by TGV. When you count in the half hour to the airport (optimistic), the security and waiting times (Europeans commonly suggest coming the the airport at least two hours before your flight), the flight is an hour and a half with Ryanair so you can also have a scratch lottery on your luxurious flight, let's say you take half an hour to get your stuff after landing and need half an hour to the city center. TGV wins, and that's without even mentioning the smoothness of the ride, amenities, leg room, walking around, restaurants and bars. Price is the only thing that goes for air travel in this case, but that's what the government needs to fix. > No; we want legroom. Already done. > We don't want that either. Isn't your electricity nuclear power anyway? What's the problem with consuming too much clean energy? Last I heard nuclear energy still costs money, clean or not. So, TGV is very good in this aspect, considering everything. It's not perfect, but it's good enough in more than one way.
ThePowerOfFuet 4y ago
Re going faster, exponentially more power is required to do so, and the infrastructure has a limit. >No, we want legroom. The Euroduplex rolling stock, of which the Avelia Horizon is the next generation, has better second-class legroom than any highway coach I've been on in my life.

progval 4y ago

> Isn't your electricity nuclear power anyway? What's the problem with consuming too much clean energy? According to a 2019 poll, 69% of French people believe that nuclear "contributes to producing CO2 and climate change". (34% answered "a lot", 35% "a little", 13% "not really", 17% "no") Source: https://www.bva-group.com/sondages/francais-nucleaire-sondage-bva-orano/ https://www.bva-group.com/sondages/francais-nucleaire-sondag...

pasabagi 4y ago
Well, it does. Nuclear plants have very high embodied carbon, as they're made out of large amounts of steel and concrete. That's obviously not as bad as a coal plant or even a gas plant. But 'a lot' is still probably correct.
- tremon 4y ago
  By that reasoning, a wind park isn't carbon-free electricity either. I wish you good luck on your campaign to convince the public, after that you can come back here and we'll talk again.
  - cinntaile 4y ago
    If we just look at how much CO2 something produces when it's ready-built we potentially ignore a huge part of the pollution. You usually do a life cycle analysis (LCA) and come up with a g CO2-equivalents/kWh. No energy source has 0g/kWh.
    - Schroedingersat 4y ago
      Not to defend nuclear, but it's competitive with solar on that front and better than anything but hydro. Keeping existing nuclear on as long as it's safe is a pretty clear win climate-wise
- triceratops 4y ago
  Can a nuclear plant produce enough energy to capture all the carbon emitted in its construction? While still being profitable, obviously.
  - pasabagi 4y ago
    Just thinking the problem through, I think that's very unlikely, unless you're in a pathological situation. So, for a nuclear plant to be profitable in a competitive market, it needs to produce energy for less than its competitors. If its competitors don't have to pay to capture carbon (through money or output) then they are always going to be cheaper per watt, and the plant is going to become unprofitable. The only way that would work is if you had chronic electricity undersupply (v. likely but also pathological) or if nuclear plants were way more efficient than alternatives (the opposite is true). Generally the argument for nuclear is you need a diverse range of energy sources to have a stable power supply, not that they are a great 'bang-for-buck' option. (An argument I agree with, fwiw). EDIT, PS: It's worth keeping in mind that carbon capture is largely an unsolved technical problem, and I think it's perfectly feasible that it will never be solved. The basic idea of burning fossil fuels for energy, then using energy to recoup the carbon from the atmosphere, just makes no sense at all. There's no world where this would be cheaper than just not releasing the CO2 in the first place.
    - DuskStar 4y ago
      If you made all the alternatives also pay to capture their carbon cost, I think nuclear would be very competitive. Obviously it blows fossil fuels out of the water, but hydroelectric also uses huge amounts of concrete, and IIRC the energy return on investment (MWh you get out per MWh it takes to construct) for solar and wind is quite poor and so I'd expect that to take a while to pay off too.
      - Retric 4y ago
        Nuclear has a vastly worse EROI than grid PV solar. Nuclear lasts longer which somewhat offsets construction costs, but needs a vast workforce continually and a maintenance and power simply to operate. As a sanity check, sub 2c/KWh solar can’t require that much energy simply because energy costs money. Nuclear on the other hand ends up having ~1,000 workers drive somewhere for 50 years which also takes energy, but that’s often ignored. That said, people love to come up with all kinds of irrelevant comparisons using vastly outdated data to make things look worse for solar while ignoring Nuclear’s downsides. For example France’s capacity factor fell below 70% when they tried to ramp up production and things would look even worse on a 100% nuclear grid.
- cinntaile 4y ago
  Over their 40+ years lifetime it becomes negligible.
  - pasabagi 4y ago
    Maybe? Because climate change is a self-feeding cycle, releasing large amounts of CO2 early, then amortizing that over decades of operation, is worse than a constant steady release. I guess you're probably right, nonetheless. It just annoys me when people post polls like this to prove that people in general are stupid, when polls generally show that ordinary people everywhere are way better on climate issues than political elites.
    - petre 4y ago
      Concrete absorbs CO2 as it cures. If you add a bit of titanium dioxide it doubles the amount of absorbed CO2.
- sanp 4y ago
  But that’s sunk cost. That’s not increasing with consumption unless u get to a point where u have to build a new plant.
- credit_guy 4y ago
  This is incorrect. A large nuclear power plant uses about 200000 cubic meters of concrete. Each m3 of concrete contributes about half a ton of CO2 emissions, so that’s a one time 0.1 MT of CO2 emissions. A coal power plant of similar size will emit more than 1 MT every - single - year. There is simply no comparison.

giraffe_lady 4y ago

Absolutely hearsay here but a family member worked for SNCF as a mechanic for TGV trains (but not the locomotive) and has said that the pantograph was the limiting factor they had designed the last generation around. That it was designed as a wear part and the top and optimal speeds were chosen based on thresholds for unacceptable wear on the transmission lines themselves, which are much more difficult and expensive to replace. He told me never to expect TGV speeds to increase significantly until we saw them ripping out the powerlines and replacing them with an entirely new system. Again I don't know if this is true! But it seems reasonable enough to me. That conversation was about twenty years ago and plenty has changed with TGV in the mean time but sure enough no top speeds have increased on any line in the system in that timeframe, and new lines are deployed with the same speeds as the older ones.

bombcar 4y ago
I've often wondered why a wheel rolling against the wire wouldn't be better, after all at those speeds you have a wheel rolling against the track and bearing the weight of the train.
- pmyteh 4y ago
  Having a low sprung weight is important for pantographs, and getting the 25kV off a rotating contactor would introduce another unhelpful electrical interface I suspect. If you want to know far more than you did before about overhead line electric systems for railways, from a predominantly British perspective, I can strongly recommend Gary Keenor's (free) book: https://archive.org/details/overhead-line-electrification-for-railways-6th-edition https://archive.org/details/overhead-line-electrification-fo...
crocal 4y ago
This correct. Power lines wear induced by pantographs is the limiting factor for TGV top speed. The engineer that can solve this problem will allow top speeds in the range of 400/500 kph on /existing/ TGV tracks. Much better problem to solve than hacking a lame hyperloop.

rcMgD2BwE72F 4y ago

Do you know that TGV tickets are very expensive? It's easy to say "faster and larger" when you can afford it. But fitting more people on a train make transportation cheaper for the mass. I'm French and many friends and family would love to take TGV on holidays but have to ride by bus (search "cars Macron") or by ridesharing (Blablacar) due to the TGV prices. SNCF recently re-launched some quite old trains under the low-cost "Ouigo Intercités" brand, because demand for cheap-but-slow transportation is more and more popular. I took one from Nantes to Paris this summer (many hours longer than by TGV) and will prefer it next time too. I could fit my bike for free there (vs 10€ in TGV, where I also usually have to disassemble beforehand).

Drunk_Engineer 4y ago
The bus is a much better travel option anyway. Trying to make travel plans with SNCF is a nightmare with their constant strikes.
- lapinot 4y ago
  In which world is the bus not a nightmare?! Waiting for it at a random bus parking where nobody knows where it arrives, almost no ability to walk around nor go to the bathroom, less space than train, no access to your big luggage.. I'm not even talking about speed or efficiency.
  - mumumu 4y ago
    Most buses on Europe have gps tracking and updated timetable available online, they are also fairly comfortable.
    - yakshaving_jgt 4y ago
      Most? Can I see the data? I'm imagining you and I exist in parallel Europes.
      - 4y ago

rospaya 4y ago

> Yes we do! Speed is limited with infrastructure, and France isn't exactly the US. There are not a lot of population centers like Germany which has 14 cities that have more than 500k people while France has four and 20% of the population lives around Paris anyway. You can get from the center of Paris to the center of Marseille (second largest city, other side of the country) in about three hours by TGV. When you count in the half hour to the airport (optimistic), the security and waiting times (Europeans commonly suggest coming the the airport at least two hours before your flight), the flight is an hour and a half with Ryanair so you can also have a scratch lottery on your luxurious flight, let's say you take half an hour to get your stuff after landing and need half an hour to the city center. TGV wins, and that's without even mentioning the smoothness of the ride, amenities, leg room, walking around, restaurants and bars. Price is the only thing that goes for air travel in this case, but that's what the government needs to fix. > No; we want legroom. Already done. > We don't want that either. Isn't your electricity nuclear power anyway? What's the problem with consuming too much clean energy? Last I heard nuclear energy still costs money, clean or not. So, TGV is very good in this aspect, considering everything. It's not perfect, but it's good enough in more than one way.

ThePowerOfFuet 4y ago

Re going faster, exponentially more power is required to do so, and the infrastructure has a limit. >No, we want legroom. The Euroduplex rolling stock, of which the Avelia Horizon is the next generation, has better second-class legroom than any highway coach I've been on in my life.