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Tesla “Model P” – a compelling case for Model S in Police fleets

Discussion in 'Model S' started by austinEV, Jul 8, 2013.

  1. austinEV

    austinEV Active Member

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    There have been some mentions of using a Tesla for fleet use, but I don’t recall seeing any workup on it, please forgive me if I am repeating. (No this is not a parody this time, so if you see some smelly assumptions call me out on it :smile: )

    I was talking to an uncle-in-law who is a police officer in a smallish Texas town. He gave me some basic facts that started my analysis engine going:

    • Cost of a sedan (Dodge Charger) ~20k (plus the cost of the equipment, computers, lights etc. I am not modeling that cost because it’s the same for any car).
    • Cars do 2 10 hour shifts and “rest” for a 10 hour shift in a 30 hour cycle.
    • A 10-hour shift would always be much less than 100 miles, even for a patrol car which surprised me. Generally they don’t just drive around, they are driving from call to call, and if no call is coming in, they idle and do paperwork.
    • Most of the gas used was idle time. When police are filing reports, using the computers, working a car accident, or just about anything else, the car is idling, since the lights and electronics would drain the battery quickly.
    • They fill the tank at the beginning of every 10 hour shift. So the cars are very topped off all the time. They buy directly in bulk so there is no retail markup, but retail markup for gas is quite small.
    • The cars are retired from patrolling at 100k, and demoted to some other purpose to 200k and then auctioned. The second 100k is for detectives and such.

    Range is less of a concern than I would have imagined. The gas guzzlers they are using (Dodge chargers) get 19mpg and have 19.1 gallon tanks. Only 362 miles of range!

    So the driving conditions are:

    • low average speed, stop and go city driving with a lot of “stop”.
    • Hours of idle time.
    • Little highway time.
    • A lot of electronic use onboard.
    • Need to have extra capacity ready all the time (running out of gas while following someone or transporting a suspect is really not an option).

    Here I am looking at an existing Model S, in terms of cost and capability. I think it could be an 85 nonP (although I suspect the “performance” is 15k upgrade that is 95% profit for Tesla, perhaps they can throw that in for free). So excluding fancy paint and pano roof figure a “model P” at about 90k to be conservative. Ideally, the car would be tweaked a bit. The styling could be toned down a bit, to raise up the roof in the back seat. Also, the back should really have a regular trunk instead of a hatchback purely because that is pretty lousy security for transporting suspects. But I suppose some bars in back of the seat would serve.

    First I looked at range to see how unpleasant it would be. The EV suffers from not being able to refill between shifts, but the model is still decent. Here I am assuming the force is using HPWC with twin chargers:
    cop1.JPG

    So while the second shift can quickly top off the ICE, an EV officer would be starting with 2/3 range. But, with just a small amount of flexibility that can be fixed. For instance, if they plugged in for as little as one hour during a shift change (which seems likely/easy anyway) you get this:

    cop2.JPG

    Which is practically the same. In fact, since the officers actually DRIVE to the fuel depot you can see that much of that 1 hour turnaround time is absorbed by the ICE trip TO the fuel, whereas the EV could charge at the station.

    Verdict: No real range concerns relative to a gas guzzler police cruiser.

    So then I went to model the cost. A police force might be paying a premium to get a “Model P” fleet, but maybe it’s worth it? I laid out my analysis a few different ways to check it and found a surprising result. With the use parameters the way I understand it, a “Model P” fleet saves money from year 1. Here are my assumptions used:

    cop3.JPG

    I worked backwards from the “mostly idle” and “much less than 100 miles/shift” to get these parameters. So 2/3 idle time to get that low mileage. I am also boldly assuming a x2 lifetime due to many fewer moving parts, but I looked at x1 lifetime as well. Finally I assumed a 1kW/hour “idle” usage for EV car plus police gear. If someone knows the idle draw of a Model S I can fill in with some estimates for actual police kits. 1kW seems generous to me though, given that police lights are LED now and a typical laptop takes 100W going full bore. I then assume an ICE maintenance cost of $5k/year and EV cost of $1k/year. This excludes the cost of tires which is a function of miles and doesn’t change.

    A look at the first 4 years:

    cop4.JPG

    Or looking long term (20 years) for a fleet of 20 cars, see graph below. Here I am assuming that the force replaces 4 cars a year. After 5 years they are over the 200k and are retired. So at 4 cars per year, this force never stops buying new cars, but if the EV lasts twice as long, they stop buying cars for 5 years. (The “1x” case below buys 4 EV’s a year just like the ICE’s with no extra lifetime assumed).

    cop5.JPG

    That is a 13 million dollar advantage from the ICE baseline to my 2x case, and this is a small police force. Astonishingly going to an EV fleet saves money from year 1. I figured most of the savings would come from my 2x lifetime advantage, but actually even x1 works. The difference in fuel costs is more dominant. The MOST dominant parameter is the more efficient idling performance. An ICE uses about 1 gallon per hour idling ($3.50 of fuel) or a kWh of idling ($0.10 of fuel). Even if I am off by a factor of 3x that is a huge efficiency.

    Verdict: EV costs far cheaper relative to a gas guzzler police cruiser.

    Tactical Advantages of an EV:
    Let’s not forget, these are Tesla’s we are talking about. So the police could outrun just about everything on the road, and maneuver like a beast. (The Dodge charger goes 0-60 in 5.1 seconds) We brag about the performance of the Model S to our friends, but the police are the people who could actually put it to work. Also, they are *quiet*. That has to be worth something to police. But to me the intriguing possibility about the “model P” Is the big 17” touchscreen. This is of marginal value to the consumer, but for police (and taxis) this would be a GODSEND. If you have seen the inside of a police car, it is basically a bunch of computer terminals perched awkwardly in front of the center stack. As far as I know, the principle use of that computer gear is for dispatch information and crime database access. With some (not insignificant) software dev, that could simply be integrated to the Model P computer and be another app they can switch to, leaving room for other gear and greatly cleaning up the interior (and taking thousands of dollars of equipment cost out of the car, although some has to go back to the SW developer since their unit volume would be low for a long time).


    Conclusion:
    Because of the way police use their vehicles, (high annual mileage, long idle times, and predictable patterns), and due to the fact that police tend to have vehicles that are large with powerful engines, switching to EV’s is especially cost effective. Certainly by the time the Gen III comes out, the advantages will be even more apparent. To the extent that EV’s make sense for the typical commuter, they make vastly more economic sense to someone operating vehicles for long hours and high daily mileage like police forces.
     
  2. TD1

    TD1 Member

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    I like the Idea.
    But what about the battery replacement costs?
    Im pretty sure Tesla cant offer the same 8year guarantee on Fleetcars with such a high usage.
     
  3. Bipo

    Bipo Member

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    Brilliant analysis, really. I hope someone in the Police reads it. Thanks for sharing it.
     
  4. hershey101

    hershey101 Member

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    That's a lot of hard work you put into the analysis, but I don't think its useful until we have more information on the GEN III. The police aren't going to buy a $100K car (thats what it ends up being after tax etc.) to replace a $20K, only to break even after 5 years. Your modeling for the Tesla should really show a 30%+ depreciation for the first year and more than 50% by the end of the first 3 years. Not to mention that you have to account for time value for money and discount for the $100K spent on the Dodge over 5 years vs. it being spent upfront on the Model S. Finally, and most importantly, the police won't switch to Tesla purely for political b.s. Not to mention that Tesla selling cars around the country to cops makes the car lose its value as an "exotic" vehicle and it becomes a common-place car.
     
  5. Clprenz

    Clprenz Member

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    just wondering, why does it have to be 90k?? whats wrong with the 60kwh? that would bring cost down to 70k minus tax credits... or 59k in illinios...
    I have mentioned it to my police department in EVTown (Normal IL) This would be really cool, they could easily put a new touch screen app or the police. Anybody know anyone in this department at Tesla?
     
  6. c041v

    c041v Member

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    Agreed, thanks for the interesting application of a Model S. A few comments;

    1. I see an awful lot of police cruisers on the back of flatbeds. Usually pretty bruised from some unfortunate incident involving the apprehension of criminals. I feel like low-unit cost keeps these cars 'disposable'.
    2. Police cruisers normally get a few suspension tweaks and some other enhancements for heavy duty use. Would a stock Model S be able to take the wear and tear? I just came from lolachampcar's thread on negative camber - Something as relatively minor as this could have huge maintenance costs as some parts, tires alone could be a fairly costly oversight in your analysis.
    3. Lifetime maintenance cost of the ICE must factor in somehow. Oil changes, transmission parts, and whatever else generally wears out quicker on these cars has to be somewhat significant in a fleet over the life cycle. That could help make your case more compelling.

    Otherwise, I think the points about already adequate power, the built-in screen and, silent profile are spot on.

    At the very least, Dubai should pick some up to add to their novelty fleet;

    http://www.dailymail.co.uk/news/article-2330799/The-police-cars-wouldnt-mind-getting-lift-Dubai-officers-drive-fleet-supercars-including-1-6m-Aston-Martin.html
     
  7. austinEV

    austinEV Active Member

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    Well, one of my models shows the whole car being replaced after 5 years. Since I am also doing a 100% range charge, that might be appropriate.

    - - - Updated - - -

    I think the Gen III will make a better case, sure. The point of the post is that the model S itself works financially. Yes, each new car will cost more but the carrying cost of disposable ICE's is also quite high. No, I don't think police departments are breaking down Tesla's door, but that they should.

    I show them depreciating to zero over 5 years, rather than mess with the residual value or variable depreciation rates. I don't see why the rate matters.

    - - - Updated - - -

    I wanted to use the 85kWh to be comparable to the Dodge. Switching to the 60kWh would mean having some isolated cases in the year in which an officer would run low on range. I was trying to lay out a case where reasonable concerns would be addressed.

    - - - Updated - - -

    That is a valid concern that I missed :) repair costs would be higher too since I assume replacement aluminum panels would be higher. However, the evidence so far is that Model S do strangely well in accidents. So the relative unlikeliness of being totalled might partially balance out the cost.

    That would only be a concern if Tesla cars were worse coming off the line than Dodges. If you assume equal quality you have equal impact.

    I modelled that above. 5k/yr for ICE, 1k/yr for EV.
     
  8. spatterso911

    spatterso911 MSP#7577 **--** MX#1891

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    There are other factors regarding the choice of car as well.. .

    The car typically has to withstand an impact of about 60-75 mph rear collision. The electronics on the car, including radios, GPS, MDT adds a substantial amount of weight to the car. The ballistic panels, cage and firearm racks are also heavy and add substantial weight. In the case of highway cruisers, the car must have push bars. It's unclear how the weight, added aerodynamic penalties of lightbar and pushbar and the like will affect the range, but assuming that everyday the Model S will have a range of 300 miles is not realistic. The range is 230...period...bar none. Range charge every day and it's 260-265...period...bar none. That's ideal miles too. A better estimate of the range with all the items above is more like 170-180 cruising on patrol. I'd be surprised if one would last an entire patrol shift unless in a small town.

    food for thought though!
     
  9. austinEV

    austinEV Active Member

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    Hmm, I hadn't considered that. Perhaps I should modify this for a Taxi fleet.
     
  10. StapleGun

    StapleGun Member

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    Everyone has brought up some good counterpoints, but nothing that I don't think couldn't be solved over time. In 15 years purchasing a fleet of ICE's will be unthinkable, but I don't think we'll really see the transition starting to happen until at least Gen III.

    Additionally, larger police forces could easily justify getting their own battery swap stations. This would eliminate any range worries because re-fueling will be nearly identical to what it is now.
     
  11. gregincal

    gregincal Active Member

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    I don't have anything of substance to add, but I did do this mockup about 6 months ago:

    police.jpg
     
  12. constraint

    constraint Member

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    There is difficulties with using it for a highway patrol, but i see no reason why it cant be used for a city or county sheriff's office assuming the car can pass the tests required for police cars (high speed rear end crash, curb jumping and so on). The real question becomes supercharging or battery replacement and costs associated with it.

    Typically at the start of a shift officers have to do a briefing at the start of their shift. That gives the car enough time to get a pretty good charge from a SC if one was installed at the police station. Also during a course of a shift you always see cop cars parked at the firehouse or off the street filing paperwork. If you have a large city you can strategically place a couple SC's in the patrol area while the cop is catching up on paper work. Swapping would ultimately be more effective, however the cost of having to purchase extra packs and the cost of the swapper itself may be too much for most muni's.

    Still think a 70k EV car cant compare with a 30k dodge charger, but considering how police use their cars it shouldn't be too long that the fleet managers start looking.
     
  13. evme

    evme Member

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    For police, a hybrid may make more sense at this point(as you said most of the gas is burned during idling). When the Gen III comes out that may change. The biggest concern is who wants to be the one to order a barricade of 80-90k cars? As it was mentioned above, being disposable is important for police cars. For a Taxi fleet, Model S and X are perfect.

    Isn't that going to incentivize people to get arrested? lol
     
  14. elecblue

    elecblue Member

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    That is one wicked bad-ass cop car! I heard a rumor about 6 months ago that TM was in discussions with a number of municipalities for this very reason. Perhaps someone at TESLIVE could ask Elon this weekend?
     
  15. VolkerP

    VolkerP EU Model S P-37

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    austinEV, great analysis and work. But I beg to differ on your conclusions.

    You identified the 66% of all duty time idling the engine as the major source of inefficiency, and how replacing a $20k ICE with a $90k EV can make up on that difference.
    Since police cars are undergoing heavy modifications when put to duty, I suggest that they add a 5kWh battery to supply all energy needs during that idle time, be it power for the computers, AC, heating, or lights. I think this can be realized for less than $70k. Heck, a Plug-In Prius has a 4.4kWh battery, electric AC unit and MSRP tops around $30k.

    Again, great work by you, but not the only possible solution.
     
  16. wormhole

    wormhole Banned

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    Very thorough work...with that said, I'd guess these cars would average well above 400 wh/mile...doesn't change economics all that much, but does change range and recharge times...
     
  17. austinEV

    austinEV Active Member

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    So to cap this thread a bit. I think I missed 2 factors that make the case weaker: 1) the cars would be made heavier by extra gear, guns, lights etc. 2) they probably get banged up enough that the 20k disposable nature is a feature not a defect. But, the next time I chat with my cop uncle I will grill him about gear weight and accident rates. I suspect both are being overblown here, but I have no facts for that.

    But, change "police" to "taxi" fleet and it gets interesting. The problem is that the charging switchover of 1-2 hours (ignoring SC/swap potential) is problematic. I suspect that cab drivers idle slightly less than cops. So then they would wear down their range in the middle of a shift and be down making no money for a charge time.
     
  18. constraint

    constraint Member

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    I wouldn't be too sure about that statement. Ever see the line for airport taxi's? In Minneapolis for instance, Taxi's have to wait in a parking lot 3 miles from the airport entrance. This line can get pretty long and this is a perfect opportunity to fast charge or swap and high amounts of idle time. In the summer the idle time usually means the car is off depending on driver preferences, but winter it is almost always on so the heaters can run. In New Orleans for instance, there was always a line of 2-3 cars waiting at every hotel waiting for the bell hop to call them over. Some times Taxi's can stand their waiting a long time before they get a call from dispatch or someone calls them over. The only difference between cops and Taxi's is that Taxi's pay for their own gas so they tend to turn their car off when idling depending on the weather.

    Now in cases such as fleet's like Taxi's, I think battery swapping makes perfect sense. The only real problem i see with Taxi's is the lack of being able to plan. I dont know if my next call is a 10 mile run or 50 mile run. At what point do you decide to swap out for a new pack or risk losing your next customer. I dont want to swap out a good pack with 100 mile range left just in the off chance my next customer wants to go 90 miles and its 15 miles from there to my swap station.
     
  19. brianman

    brianman Burrito Founder

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    I didn't say it then so I'll say it now.

    This picture scares me. It's impossible to outrun or b.s. a cop driving the same thing you are.
     

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