Vision for the Robotaxi Charging Network

I thought it would be fun to envision what the Robotaxi charging network will look like. My vision for the future:

TLDR: 380V DC global standard, fixed platform sans moving parts and with cooling plate.

Let's start with likely objectives: Scalable, High Throughput, Safe, Reliable, Resilient, Low Cost, Energy Efficient, Geographic coverage.

Here is how I think the objectives might be achieved:

• Scalability: Mass manufactured off board/stationary charger modules no more than a few stations per module. Maybe delivered like superchargers in a row as many as can fit on a trailer, pre manufactured and ready to drop and connect. Deploy without necessarily investing in new transmission which means it needs to directly connect and self adjust in any major country to standard 380-480V 50-60Hz 3 phase.
• Reliability: No movable cables or other moving parts of any kind.
• Coverage: Expand each location gradually as Robotaxis deploy.
• High Throughput: Built for as fast a charging speed as the batteries can reasonably tolerate without too much degradation or heat loss, to maximize throughput per real estate footprint.
• Resilience and Redundancy: Withstand various challenges such as extreme weather conditions and brownouts/blackouts, by having a few smaller locations per city rather than one large. Indoor locations or at least roof cover for less exposure to the elements. This will also make it easier to wash and clean the cars as they charge.
• Cost and energy efficiency: Since there will be more vehicles than chargers, it is obviously cheaper to put the rectifier and charger on the stationary side. This means the cars will be DC only, like the Tesla Semi. Shortest possible cables in the car, i.e. connect under the car close to the battery. A pedestal or subway 3rd rails of equal height of the vehicles’ ground clearance with no moving parts, 3 contact surfaces for +, - and ground. The vehicle mass minus suspension could be responsible for correct pressure by making pedestal slightly higher than ground clearance. If the three contact points sufficiently encircle the vehicle COG, contact could be achieved without any spring loaded contacts. Ground connector could do double duty as heat transfer plate/heat exchanger to unload the internal HVAC and so increase efficiency and longevity. Since there needs to be liquid cooling in the charger already, should be easy to arrange. No voltage step up. That means < 380 V max battery voltage.
• Safety, Security and Cybersecurity: Zero tolerance for electrocution. Hardened computer systems so that connectors are energized only when a vehicle is charging. Mid/under car platform could be larger than the connector plates to prevent anybody from crawling under and touching energized connectors.
• Strategic Placement: Locate charging stations near high-demand areas such as airports, train stations, and city centers, as well as along intercity routes.
• Energy Management: A balance act between throughput, time varying cost of electricity, available ‘green’ electricity and on site batteries. In many cases on site batteries may be more cost effective than extra real estate, i.e high throughput in a small footprint even if the grid can't support momentary power requirements.
• Final note: The reason I'm not bringing up inductive plates like they have at BEV bus stops is that a robotaxi needs to be able to run longer than between bus stops and along non pre determined routes which then negates the benefit of inductive plates. Unless you blanket the whole road which seems more expensive than sufficient battery for the day or maybe rush hour. Could have some small battery cars to last rush hour and some large to last the day and road trips.

What's do others think the Robotaxi charging network will be?

"Tesla Robot Taxi" by Mike Licht, NotionsCapital.com is licensed under CC BY 2.0.
Admin note: Image added for Blog Feed thumbnail

 

[Supcom]

What's do others think the Robotaxi charging network will be?

The robotaxi heads to the nearest supercharger and is plugged in by the Optimus robot stationed there. The same robot cleans the windows, cameras, adds air and washer fluid as required and vacuums the interior.

Charging is only one part of required robotaxi service.

 

[KerrySkates]

V4 Superchargers are up to 1000V, so I don’t understand why you would spec out 380V for Robotaxi. These vehicles need to get back on the road as fast as human-controlled vehicles. It would be best for the Robotaxi to keep up with the industry in the respect.

 

[Olle]

The robotaxi heads to the nearest supercharger and is plugged in by the Optimus robot stationed there. The same robot cleans the windows, cameras, adds air and washer fluid as required and vacuums the interior.

Charging is only one part of required robotaxi service.

Seems like a good idea for sharing the stations. I see cost as a major hurdle with SC though. A private car supercharges a few times a year. A robotaxi would need SC every day so the amount of chargers per car would be much higher. At 20 million robotaxis per year:

• Additional 10000 miles of high power conductor from battery packs to charge ports.
• Thousands of extra miles of very expensive supercharger cables.
• Lost energy in the extra cable loops. Say a V4 SC has 5 meters more conductor than a ground to battery direct connection (2m up in post, + 2m cable + 1m inside car)

It would of course be smart if the robotaxis could smooth SC usage by driving themselves to underutilized SC but just the volume of robotaxi makes one order if its worth it with the sheer amount of new SC necessary. Definitely a double edged sword.

 

[Olle]

V4 Superchargers are up to 1000V, so I don’t understand why you would spec out 380V for Robotaxi. These vehicles need to get back on the road as fast as human-controlled vehicles. It would be best for the Robotaxi to keep up with the industry in the respect.

But since the cells are the limiting factor and not the pack voltage you could still charge fast. You could pick any charging speed and the conductor cost will be a function of the voltage. Like I wrote, the reason for 380V is that that's the lowest default voltage available globally. Many are higher, e.g. US is 480 V but there are benefits to a global standard. 1000V is a huge saving on conductors, which is important for an SC loop. If you go back and listen to the earnings calls, Elon and Drew said that for a Model Y the savings would be about $100/car for going to 1000V, but are only going to Maybe 460 to 500 on those. They also said that there is no chance robotaxi will use high voltage.

Since the suggestion for robotaxi is direct connection to battery, there won't be any conductor length to speak of, so any no advantage of higher voltage from a conductive standpoint, would be outweighed by the energy loss and equipment cost of step up.

 

[Lance From Jax]

The robotaxi heads to the nearest supercharger and is plugged in by the Optimus robot stationed there. The same robot cleans the windows, cameras, adds air and washer fluid as required and vacuums the interior.

Charging is only one part of required robotaxi service.

Does Optimus have a pocket to put tip in?

 

[Supcom]

Does Optimus have a pocket to put tip in?

Tap your phone on his palm to transfer some bitcoin.

 

[moa999]

smart if the robotaxis could smooth SC usage by driving themselves to underutilized SC

I wouldn't be surprised if robotaxis have dedicated Superchargers, with automated queuing to maximise efficiencies.

In bigger cities (thinking New York, Hong Kong etc) will also need auto-navigation in carpark structures, maybe with QR codes to give the cars additional info.