Electric Cars are failing with Taxi Drivers

This article might be of interest to Arlington Co. Virginia who had been considering a Leaf taxi force. But the last I heard that plan was stalled ...not sure current status.

 

I've never thought a battery electric car would be very good for taxi use or for car rental.

I would think taxis get driven a lot of miles per day. With only 70 miles range, wouldn't they need to be quick charging every day or multiple times a day? Quick charging is supposed to shorten battery life.

Battery electrics for car rental don't seem good either. I just drove 160 miles in a few hours in rental car. How would that have worked in a Nissan Leaf? It wouldn't have.

Battery electrics don't seem suitable for taxis, but maybe for short distance rental.

 

Nissan's Andy Palmer discusses Leaf battery degradation crisis [w/video]

"80 percent capacity left after five years of normal usage, and after 10 years, it would be 70 percent. Some Leafs would be doing better and some worse than that, based on driving conditions over the years. Nissan figured there were four main variables that would affect those assumptions:

1. Speed and type of driving you do – if you're always going at highway speeds, there will be more degradation.
2. Frequent use of fast charging – Nissan recommends no more than once per day.
3. Mileage on the vehicle – with 12,500 per year being the assumed average in Nissan's testing.
4. What the temperature extremes are – both cold and hot."

 

The whole article's premise is a joke. The point of an EV is for short trips that the majority of people make every day. The point of a taxi cab is to run 8 hours a day shuffling people around and sitting waiting all the time. The use models are completely different, and really I don't see how EV's with today's range will work for that. They can work for urban rentals, but that's about it.

 

spreading the FUD ...

elsewhere in the source article the author points out ...

 

maybe the summer heat in combination with elevations?

Osaka - Wikipedia, the free encyclopedia

 

What country are you referring to?

In the United States, we drive about 3 trillion miles per year. (1)

Of course, many of those miles are in the form of long-haul trucks and other vehicles it would not currently be practical to convert into battery electric form.

A typical vehicle might get around 2.5 miles per kWh from the grid but let's be conservative and say 2 miles (I personally get 3.5-4.0 in my Chevy Volt on a 30 day average).

1.5 trillion kWh = 3 trillion miles / 2 miles per kWh

The US electricity grid generated about 4 trillion kWh in 2011. (2)

Sure, maybe the EV charging might be concentrated at certain times of the day like just after people arrive at work (assuming daytime charging). On the other hand, most vehicle charging is expected to occur during overnight hours when grid usage is about half the level as it is during the daytime.

In reality then, we already have enough excess overnight plant capacity to charge way more plugin cars than are expected to be purchased in the near future.

Even in the extreme scenario where all vehicles are replaced with EVs and are only charged during the day it seems unlikely that we would need any more than 2 times our current generating capacity.

In reality, we are not all going to instantly (or ever) go into the electric taxi business.

Most EVs will be charged overnight which will spread out and even the average grid load thereby increasing overall grid generation efficiency.

The EV fleet will take decades to replace ICE vehicles and energy efficiency and conservation will help reduce non-EV future consumption.


(1) Annual Vehicle-Miles Traveled in the United States and Year-over-Year Changes, 1971-2012

(2) http://www.eia.gov/forecasts/aeo/er/pdf/tbla8.pdf

 

I would be interested in seeing some references for this statement.

Texas seems to be adding renewables and some natural gas fired generation rather than burning oil, coal, or nuclear. I think this would be the trend for adding any new generation in North America. I also think that most electric vehicle charging would take place at night, minimizing the need to add any additional generation capability. Additionally, the integration of EV batteries into grid stabilizing mechanisms accelerates the effectiveness of intermittent sources like wind and solar.

 

The humidy may trigger more HVAC load, but I don't think it directly affects the battery or the electric drive train.

 

I wouldn't characterize HVAC loads as battery "degradation" but an increased load would result in more battery cycling (charge/discharge) and shorter EV range per charge.

It would be interesting to know what the Osaka Taxi drive cycles and charge cycles look like. Are they charging between every trip or do they try to minimize charge cycles? I would think they are charging to 80% at each opportunity, and occasionally charging to 100% when they know in advance they have a destination outside their regular range.

 

Shame but I could see it coming. It's the inflexibility of it all. A 70 mile range, but you have got to leave a buffer for those indecisive customers etc. Then there's the time charging and the cost of the vehicle. An EV taxi needs at least 150 mile range.

The other issue I found with the Prius is cooking the HV battery. Start, stop, start, stop for 10 hours a day every day (more if the car is run 24/7) really takes its toll. I had a number of times where the Prius almost tried to avoid use of the HV battery by revving its engine to power the a/c etc.

With an EV like the Leaf there's the life of the battery. 70 miles when new quickly (in the life of a 30,000 mile a year taxi) becomes 50 miles, becomes 40 miles which is next to useless. In the UK 1 mile = £1/$1.50 earnt (gross). A ten hour shift had to make £120/$181 gross, for me to take minimum wage after running cost deductions (tax, fuel, replacement car, radio rentals etc), so to make £12/$18 an hour you had to work the car. Obviously £12/$18 a hour isn't great, so to make a living you had to earn £150/$227 a day or 150 miles (these are figures BEFORE running costs!).

Now you see the problem with a 70 mile range on a £26,000/$39,000 car (uk prices), let along the 1 hour charging time where the car's off the road.

A nice idea but not viable without support.

 

taxi's are probably the worst possible usage for the EVs.

From pollution standpoint, probably FCHV would be most useful eventually.

 

Could the problem be that the LEAF's battery is air-cooled instead of having a liquid-cooling system, as in the Volt? I wonder if the Volt or Tesla Model S would experience the same degradation in Osaka's environment.
I am surprised the quick-charging did not cause any degradation. I guess that's because its DC?
I think for an electric taxi to work, the best scheme is what Better Place proposes. Swapping out the battery prevents it from overheating, and it can trickle charge using cheap, overnight electricity. And you pop in a cool, fully charged battery so the strain on any one pack is much, much less than if they are permanently attached to the car. Plus, the taxi headquarters are ideal locations for the swap station, especially if shared between all Osaka cab companies. "Customers" for this service are all Osaka taxis, which takes away the chicken-and-egg situation for building out a similar network for private users.

Better Place's battery-swapping Coda taxis coming to California in 2014

 

Maybe they just need to build some chilled quick charging garages for use in the summer.

The article doesn't seem to include very much data, like how many of the taxis are experiencing battery capacity degradation, experiencing longer charging times, or having reduced EV range. Articles like this have a history of assigning a "trend" to an outlying case. It would be sad to find that a single failed cell in one Leaf was the fuel for this article and "they" is one driver.

 

A coda taxi? Yeah that'll never work. Have you seen the size of the thing?