In order to use a tool effectively, it’s not enough to deploy it for the properties you selected it for. One has to accept it’s peculiarities and shortcomings as well.
This is true for hammers, screwdrivers and cars. In the end, this means that my favourite hammer may well perform below optimal, exactly because accepting it’s shortcomings limits my ability to consider other options. Other hammers or another tool altogether. The attitude I’m describing is the result of the so called confirmation bias; see e.g. confirmation bias on Wikipedia.
I’ve written a lot about the Tesla Model S in this blog. Mostly in a positive way, but not always. It’s hard to tell whether I’m suffering from confirmation bias or not (you are probably a better judge). After 10K kilometers, I’m prepared to start again en look at my experiences with the Model S as if it’s forced upon me and as if I can exchange it for any other car when I feel necessary (which is most likely true anyway). This will avoid the most important causes of confirmation bias, which is mainly a strategy to cope with complex situations and to motivate oneself doing something new but scary.
I’ll write about costs, charging Logistics and environmental impact. Yeah, about comfort too.
If you want to save time and skip to finally, please do so.
I complained about the charging cable being locked at both the car and charging pole. As Wido explains in 10.000 elektrische kilometers however, this is absolutely necessary. Charging without locked connectors is not recommended as it allows one of the connectors to be pulled out while transferring huge amounts of current at 240V or higher. Imagine the incremental corrosion damage inflicted upon the connector with each turn ending in a fire as the connectors get hot because of all the sparks while charging for it’s very last time. No conformation bias here, I was too sceptical about the charging procedure and didn’t realise that locking the connectors was actually useful and was not designed for annoying me.
This is also the reason why not to keep your charging pole end of the cable plugged in, because you’re the only one using it. The car
end of the cable should not hang around in outdoor conditions.
Charging is a pain however. It takes me approximately 25 seconds to connect or disconnect the pair of connectors, including signing on and signing off with my EVBox charging-card. Hence a full charge-cycle takes 50 seconds (25 twice; in and out of course).
In order to compare this with my previous car (the already mentioned Volkswagen Passat R36), I need some figures. I need to come to a number which tells me how much time is spent charging (or getting petrol) per km.
The petrol car has a slight advantage, as it is easy to optimise visits to the petrol station. These are located close to each other and it doesn’t matter where I go, it always takes seven minutes. Based on my trips in October and November, the amount of charging/loading time lost with a petrol card would be: 969 milliseconds per kilometer; or 45 minutes every single month.
With an electric (ev-only!) it is a lot harder to cancel out the time lost with charging logistics. There’s not a lot of charging stations and it is very impractical to use a charger en route, because charging-time is ridiculously high. An EV-driver will avoid charging at a non-destination location.
Based on October and November again, I spent 839 milliseconds per kilometer running around with cables: 39 minutes in total each month. That’s 6 minutes gained!
I know now that this amount can be reduced, as I’m less of a victim of range anxiety these days. Also, more about this later, charging at work is a lot more cost-effective than charging at home. When possible (as of the first of February 2014), I may be able to cut the number of charges to 30 per month (it was 47). This actually happened in January 2014 already.
Have you ever gone of the highway for petrol and discovered that the gas station was closed or out of service? Well, this hardly ever happens; maybe 1 out of 50 times. With public chargers things are a bit different. Of the 94 times I charged in October and November, I encountered 5 malfunctioning poles, none of which were recoverable while talking to it’s help desk. On one occasion, charging was vital in order to complete the day’s routine, I had to go and look for a charger pole in an OK state, this took 9 minutes.
The local government of Utrecht complains about non-EV cars being parked at charging-locations. This has happened to me only once, in the city of ‘s-Hertogenbosch. The charging pole turned out to be one of the malfunctioning kind; I could still reach it with my special 8m cable. I’m pretty sure the complaints of the Utrecht government have a political or strategical background (i.e. good old Soviet Union propaganda).
Do not charge yet!
Tesla recommends connecting the car to a charger as often and as long as possible. There are lots of reasons for this: power used for conditioning of the battery and running the air conditioning unit is drawn from the pole, if available, and not the battery. Also, if you make a last-minute decision (well, last two hour decision) to max-charge your car instead of levelling it to 90% capacity, you can do so from your armchair.
My situation doesn’t allow this. I have a (for me only) charging pole at work. This delivers me 11kW now (and 22kW as of January 2014) at a price of €0.12 per kWh. At home, I can only use a public charger as I don’t have a garage and can only park at the opposite side of the road, if at all possible to get closer than 15m from my house.
Public chargers are fine though, they’re located 60 and 120m from my house and frankly, with my petrol R36 I was happy to park that close to my house.
The pricing at the public charger is €0.28 per kWh, which is a lot more than what my office pays. The low price I pay at the office is due to the mass-contract we have with our energy supplier and taxes. It’s mainly taxes; these boil down to €0.1410 per kWh, but above 10MWh per year it’s reduced to €0.0513. This is why my office ends up paying €0.12 per kWh (our Unix servers have to run too, you know).
Note that although this amount of 10MWh seems like a lot, my Model S comes close to surpassing it. Based on October and November, I will use 8.5MWh per year (not 9.3MWh as I subtract one month of driving due to holidays, more on that later). 3 more Tesla’s at the office and we will most surely progress into the next tax-class for electricity!
After 10K kilometers my range anxiety has moved from high to moderate. Hence, I’m perfectly willing to not charge, even when it is possible. This contrasts with Hybrid EV owners: their batteries are almost always empty upon reaching their destination, they will always want to charge!
Not always charging requires a bit of planning though. I used max range three or four times, because I knew that the following day I was going to travel over 250km.
In September, the indicated range of a 90% loaded battery was 382km (which should cater for a range of 382km at a rate of 200Wh/km). This is actually exactly the outcome of dividing the energy (90% of 85kWh) and the typical rate. This rate is carefully, I’m sure, determined using a standardized ISO car trip. I’m not that ISO employed driver however. I’m doing 260Wh/km, so my range becomes: 294km. 250km seems like a good water mark for making decisions about swapping cars or taking the train.
I drove more than 250km on a single day, on 3 occasions in 3 months. 301km, 324km and 383km to be exact. All trips were done while adding power during the day, without that, my Tesla would not be able to complete these trips. The 301km to home, the Hague and home again was juiced up also, but the charger at the parking garage in the Hague let only 5.75kWh through in 4 hours: an extra 22km, 7 of which were really necessary, as I forgot to load up to 100% that day (which would have given me a range of 326km).
Although in September a nominal range of 382km was indicated, December had worse news which I had already seen coming in November. With the cold weather (I hope that it is the weather and not a malfunctioning battery) the indicated range went down to: 341km at 90%. I’m afraid that my trip to and from the Hague on a Friday night will not ever succeed in the winter if I don’t charge at 100%.
Of course using 260Wh/km for these calculations is not really fair. When you see a dead battery coming, you will ultimately slow down and start not driving like a maniac. I’ve done 200Wh/km for more than 40km in a stretch, so this is possible (but boring).