3 ms·
If you are already adding batteries to the train to capture the regenerative breaking energy, why not use that same energy to accelerate again, therefore saving
by aftbit 4y ago
If you are already adding batteries to the train to capture the regenerative breaking energy, why not use that same energy to accelerate again, therefore saving the fossil fuel energy in the diesel generator? Surely that would be more efficient than DAC in a CO2 sense?
- NegativeLatency 4y agoOr just go fully electric overhead like they do in northern european countries. Some of the ore trains in the far north generate a fair bit of electricity from regenerative braking that's then used by other trains going uphill or fed into the local power system.
- cinntaile 4y agoThese trains in case anyone is wondering. https://en.m.wikipedia.org/wiki/Iore https://en.m.wikipedia.org/wiki/Iore
- NegativeLatency 4y agoThanks, I was looking for them but couldn't remember the name > From Riksgränsen on the national border to the Port of Narvik, the trains use only a fifth of the power they regenerate. The regenerated energy is sufficient to power the empty trains back up to the national border.
- sandworm101 4y agoThe flip side too is that the power generated by a braking train is more likely to be in the voltage range needed by other trains in the system. It is always better the use electricity locally and in the same voltage rather than convert it to grid power.
- tonmoy 4y agoBecause the motion of the train would alleviate the need for large power consuming fans.
- bragr 4y agoWhich just makes the train less efficient and need more power? These carbon capture systems only work when the input energy is free (both financially and carbon-wise), but it seems like there's better and more efficient for uses the dynamic breaking energy (electric or hybrid trains).
- elil17 4y agoFans are inherently pretty inefficient. If you want to generate airflow across a surface, it's more energy efficient to move the surface than it is to move the air (assuming you have negligible non-fluid friction, which trains do). Motors can be over 90% efficient. With a fan, you have the efficiency of the motor and then, on top of that, the static efficiency of the fan, which is often less than 50%. We use fans when it's not practical to move the things we want to create airflow over (which is the vast majority of the time). Otherwise, we use the object's own motion. This is the principle behind ramjets.