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I thought this sentence at the end was quite interesting: > BHP’s modelling shows that battery charging time may be the biggest cost on the electric side, some

I thought this sentence at the end was quite interesting: > BHP’s modelling shows that battery charging time may be the biggest cost on the electric side, something that dynamic charging can reduce significantly. For an industry like mining, the biggest cost of switching to electric isn’t buying vehicles, or batteries or setting up charging stations: it’s the downtime they experience while charging.

audunw 3y ago
Very interesting. Makes me imagine a battery swapping station for a huge mining truck. Probably not feasible but I’m sure it would look awesome if it was.
- pixl97 3y ago
  They have hybrid test trucks that can power themselves via overhead lines for the uphill loaded portion of the trip. I wonder if something like that could reduce battery usage and time to charge.
  - atourgates 3y ago
    That makes a lot of sense. I went in a road trip in our EV yesterday pulling a trailer for the first time. We basically drove down into a valley in the morning, and back up out in the evening. As you could imagine, we got basically infinity range going downhill, and much much shorter range going uphill. A track that powered/charged mining trucks while they were hauling material up, coupled with regenerative breaking seems like it could pretty much solve charging for that application.
    - defrost 3y ago
      Even better, many BHP iron sites in the Pilbarra are mesa mining .. they drive up unloaded and roll down with 100+ tonnes - plenty of opportunity to gravity charge while retarding downhill motion (free wheeling a laden HaulPak down a mesa doesn't end well).
      - jacquesm 3y ago
        > free wheeling a laden HaulPak down a mesa doesn't end well I think you win the understatement of the month award.
      - discordance 3y ago
        That’s the principal behind Fortescue’s infinity train: https://newatlas.com/transport/fortescue-wae-infinity-train-electric/ https://newatlas.com/transport/fortescue-wae-infinity-train-...
        westurner 3y ago
        Regenerative braking in trains: https://www.google.com/search?q=regenerative+braking+trains https://www.google.com/search?q=regenerative+braking+trains Regenerative braking: https://en.wikipedia.org/wiki/Regenerative_braking https://en.wikipedia.org/wiki/Regenerative_braking From https://news.ycombinator.com/item?id=27579732 https://news.ycombinator.com/item?id=27579732 : > In Scandinavia the Kiruna to Narvik electrified railway [...] The regenerated energy is sufficient to power the empty trains back up to the national border Is re-planning routes for regenerative braking solvable with the Modified Snow Plow Problem (variation on TSP Traveling Salesman Problem), on a QC Quantum Computer; with Quantum Algorithmic advantage due to the complexity of the problem? From "Snow plow routing problem": https://en.wikipedia.org/wiki/Snow_plow_routing_problem https://en.wikipedia.org/wiki/Snow_plow_routing_problem : > The snow plow routing problem is an application of the structure of Arc Routing Problems (ARPs) and Vehicle Routing Problems (VRPs) to snow removal that considers roads as edges of a graph. > The problem is a simple routing problem when the arrival times are not specified.[1] Snow plow problems consider constraints such as the cost of plowing downhill compared to plowing uphill.[2] The Mixed Chinese Postman Problem is applicable to snow routes where directed edges represent one-way streets and undirected edges represent two-way streets. [3] Arc routing > Algorithms: https://en.wikipedia.org/wiki/Arc_routing#Algorithms https://en.wikipedia.org/wiki/Arc_routing#Algorithms : > Finding an efficient solution with large amounts data to the Chinese Postman Problem (CPP), the Windy Postman Problem (WPP), the Rural Postman Problem (RPP), the k-Chinese postman problem (KCPP), the mixed Chinese postman problem (MCPP), the Directed Chinese Postman Problem (DCPP),[8] the Downhill Plowing Problem (DPP), the Plowing with Precedence Problem (PPP), the Windy Rural Postman Problem (WRPP) and the Windy General Routing Problem (WGRP) requires using thoughtful mathematical concepts, including heuristic optimization methods, branch-and-bound methods, integer linear programming, and applications of traveling salesman problem algorithms such as the Held–Karp algorithm makes an improvement from O(n!) to O(2^{n}n^{2}).[9] In addition to these algorithms, these classes of problems can also be solved with the cutting plane algorithm, convex optimization, convex hulls, Lagrange multipliers and other dynamic programming methods. In cases where it is not feasible to run the Held–Karp algorithm because of its high computational complexity, algorithms like this can be used to approximate the solution in a reasonable amount of time.[10] QC algos for TSP and similar: - QISkit tutorials > Max-Cut and Traveling Salesman Problem: docs/tutorials/06_examples_max_cut_and_tsp.ipynb: https://qiskit.org/ecosystem/optimization/tutorials/06_examples_max_cut_and_tsp.html https://qiskit.org/ecosystem/optimization/tutorials/06_examp...
pixl97 3y ago
A fair portion of their huge equipment is already connected to a power cord, so electricification isn't a problem itself. But pretty much everything is moving 24/7. For things like heavy shovels uptimes are commonly 88% per year. When you look at how much maintenance is needed to keep running in these rough environments it's a pretty amazing number.
- algo_trader 3y ago
  Please see my sibling comment. Do we really use 2000A cables running around a work site? Are they buried ?
  - pixl97 3y ago
    Yep, and no mostly not buried. They have cable tractors to move around the wires and heavy spools. At the interface they'll have it lifted in places so the trucks don't drive over it.
defrost 3y ago
The mining trucks are 100+ tonne (carry capacity) Haul Paks with a (say) 30 minute turn around time from excavator to loadout (dumping into train) and back again. The trucks are already "electric" having diesal generators that power electric axle motors. Dynamic charging probably means auto hooking a charger at the excavator (which are often electric - they don't move much and can have fat ass HV cables running to them that are dragged when the excavator moves) to boost batteries on the trucks while they park as they're loaded. Optimal performance is no truck idle save when being loaded - dumping is relatively quick.
- algo_trader 3y ago
  > fat ass HV cables running to them Do you a more exact specs? Maybe MV 10kV-40kV ? And how thick are these cables? Do they carry 2000A snaking around the site?
  - defrost 3y ago
    > Do you a more exact specs? Yes. (It's also a fun bit of internet search challenge best left for the reader) > And how thick are these cables? Thicker than a snake, thinner than a human torso. Imagine the thinnest part of a Toyota Landcruiser after a HaulPak runs over it ... https://www.youtube.com/watch?v=4TskUzmg6Sk https://www.youtube.com/watch?v=4TskUzmg6Sk
  - 95014_refugee 3y ago
    There are a number of “standards”, but e.g. Liebherr are using 6kV for their newer small electrified excavation equipment. Cable size obviously varies based on the needs of the equipment, but “not small”, and yes, they are routinely surface-laid around the site. Larger sites do the predictable step-down thing to reduce IR losses. Many of these systems have been around for quite a while, but the move into smaller scale (sub-100t) gear seems to be picking up.
  - atourgates 3y ago
    Hard to get a sense of scale, but you can see them running across the ground in this video: https://youtu.be/Kw-enXeOnKE?t=101 https://youtu.be/Kw-enXeOnKE?t=101

audunw 3y ago

Very interesting. Makes me imagine a battery swapping station for a huge mining truck. Probably not feasible but I’m sure it would look awesome if it was.

pixl97 3y ago
They have hybrid test trucks that can power themselves via overhead lines for the uphill loaded portion of the trip. I wonder if something like that could reduce battery usage and time to charge.
- atourgates 3y ago
  That makes a lot of sense. I went in a road trip in our EV yesterday pulling a trailer for the first time. We basically drove down into a valley in the morning, and back up out in the evening. As you could imagine, we got basically infinity range going downhill, and much much shorter range going uphill. A track that powered/charged mining trucks while they were hauling material up, coupled with regenerative breaking seems like it could pretty much solve charging for that application.
  - defrost 3y ago
    Even better, many BHP iron sites in the Pilbarra are mesa mining .. they drive up unloaded and roll down with 100+ tonnes - plenty of opportunity to gravity charge while retarding downhill motion (free wheeling a laden HaulPak down a mesa doesn't end well).
    - jacquesm 3y ago
      > free wheeling a laden HaulPak down a mesa doesn't end well I think you win the understatement of the month award.
    - discordance 3y ago
      That’s the principal behind Fortescue’s infinity train: https://newatlas.com/transport/fortescue-wae-infinity-train-electric/ https://newatlas.com/transport/fortescue-wae-infinity-train-...
      - westurner 3y ago
        Regenerative braking in trains: https://www.google.com/search?q=regenerative+braking+trains https://www.google.com/search?q=regenerative+braking+trains Regenerative braking: https://en.wikipedia.org/wiki/Regenerative_braking https://en.wikipedia.org/wiki/Regenerative_braking From https://news.ycombinator.com/item?id=27579732 https://news.ycombinator.com/item?id=27579732 : > In Scandinavia the Kiruna to Narvik electrified railway [...] The regenerated energy is sufficient to power the empty trains back up to the national border Is re-planning routes for regenerative braking solvable with the Modified Snow Plow Problem (variation on TSP Traveling Salesman Problem), on a QC Quantum Computer; with Quantum Algorithmic advantage due to the complexity of the problem? From "Snow plow routing problem": https://en.wikipedia.org/wiki/Snow_plow_routing_problem https://en.wikipedia.org/wiki/Snow_plow_routing_problem : > The snow plow routing problem is an application of the structure of Arc Routing Problems (ARPs) and Vehicle Routing Problems (VRPs) to snow removal that considers roads as edges of a graph. > The problem is a simple routing problem when the arrival times are not specified.[1] Snow plow problems consider constraints such as the cost of plowing downhill compared to plowing uphill.[2] The Mixed Chinese Postman Problem is applicable to snow routes where directed edges represent one-way streets and undirected edges represent two-way streets. [3] Arc routing > Algorithms: https://en.wikipedia.org/wiki/Arc_routing#Algorithms https://en.wikipedia.org/wiki/Arc_routing#Algorithms : > Finding an efficient solution with large amounts data to the Chinese Postman Problem (CPP), the Windy Postman Problem (WPP), the Rural Postman Problem (RPP), the k-Chinese postman problem (KCPP), the mixed Chinese postman problem (MCPP), the Directed Chinese Postman Problem (DCPP),[8] the Downhill Plowing Problem (DPP), the Plowing with Precedence Problem (PPP), the Windy Rural Postman Problem (WRPP) and the Windy General Routing Problem (WGRP) requires using thoughtful mathematical concepts, including heuristic optimization methods, branch-and-bound methods, integer linear programming, and applications of traveling salesman problem algorithms such as the Held–Karp algorithm makes an improvement from O(n!) to O(2^{n}n^{2}).[9] In addition to these algorithms, these classes of problems can also be solved with the cutting plane algorithm, convex optimization, convex hulls, Lagrange multipliers and other dynamic programming methods. In cases where it is not feasible to run the Held–Karp algorithm because of its high computational complexity, algorithms like this can be used to approximate the solution in a reasonable amount of time.[10] QC algos for TSP and similar: - QISkit tutorials > Max-Cut and Traveling Salesman Problem: docs/tutorials/06_examples_max_cut_and_tsp.ipynb: https://qiskit.org/ecosystem/optimization/tutorials/06_examples_max_cut_and_tsp.html https://qiskit.org/ecosystem/optimization/tutorials/06_examp...

pixl97 3y ago

A fair portion of their huge equipment is already connected to a power cord, so electricification isn't a problem itself. But pretty much everything is moving 24/7. For things like heavy shovels uptimes are commonly 88% per year. When you look at how much maintenance is needed to keep running in these rough environments it's a pretty amazing number.

algo_trader 3y ago
Please see my sibling comment. Do we really use 2000A cables running around a work site? Are they buried ?
- pixl97 3y ago
  Yep, and no mostly not buried. They have cable tractors to move around the wires and heavy spools. At the interface they'll have it lifted in places so the trucks don't drive over it.

defrost 3y ago

The mining trucks are 100+ tonne (carry capacity) Haul Paks with a (say) 30 minute turn around time from excavator to loadout (dumping into train) and back again. The trucks are already "electric" having diesal generators that power electric axle motors. Dynamic charging probably means auto hooking a charger at the excavator (which are often electric - they don't move much and can have fat ass HV cables running to them that are dragged when the excavator moves) to boost batteries on the trucks while they park as they're loaded. Optimal performance is no truck idle save when being loaded - dumping is relatively quick.

algo_trader 3y ago
> fat ass HV cables running to them Do you a more exact specs? Maybe MV 10kV-40kV ? And how thick are these cables? Do they carry 2000A snaking around the site?
- defrost 3y ago
  > Do you a more exact specs? Yes. (It's also a fun bit of internet search challenge best left for the reader) > And how thick are these cables? Thicker than a snake, thinner than a human torso. Imagine the thinnest part of a Toyota Landcruiser after a HaulPak runs over it ... https://www.youtube.com/watch?v=4TskUzmg6Sk https://www.youtube.com/watch?v=4TskUzmg6Sk
- 95014_refugee 3y ago
  There are a number of “standards”, but e.g. Liebherr are using 6kV for their newer small electrified excavation equipment. Cable size obviously varies based on the needs of the equipment, but “not small”, and yes, they are routinely surface-laid around the site. Larger sites do the predictable step-down thing to reduce IR losses. Many of these systems have been around for quite a while, but the move into smaller scale (sub-100t) gear seems to be picking up.
- atourgates 3y ago
  Hard to get a sense of scale, but you can see them running across the ground in this video: https://youtu.be/Kw-enXeOnKE?t=101 https://youtu.be/Kw-enXeOnKE?t=101