Leasing an EV, with data

I was really tempted to buy an Electric Vehicle due to a promotional lease price earlier this year. However, buying an EV has a whole lot of implications. One of the most important one being having a method/place to charge your car everyday. Leasing a car has its own problem too: you’re paying for the mileage, how many miles do you need every year? And of course, the final question: does this purchase make sense?

I tried to approach these problems with data and it eventually lead me to the decision to replace my car with a 2016 Volkswagen e-golf.

Problem Space

I had to first realize what questions am I really asking and need answers for:

  1. How do I charge it up everyday?
  2. How many miles am I driving every year?
  3. How much will I spend extra or save?

These are all quantitative questions, ones that I will be able to solve with real-data and to have confidence to make a choice.

The Charging Problem

“Range Anxiety”, a #EVproblem that you might hear a lot among EV lookers/drivers.

Most entry level electric vehicles out there have smaller battery capacity then the famous Tesla Model S, let along a gas car. The e-golf I was looking at only runs 88 miles on one charge. Given that my commute is about 20 miles one-way, I will have to charge at very least every other day.

I’ve started looking into charging options. Being an apartment renter myself, charging at home is not a feasible option. You might have better luck if you are an condo owner: it will have to be taken through HOA, more complicated installation due to shared electricity in the garage and finding a fair way to payback HOA for the electricity you used. It would definitely be the best option if you are a homeowner.

With home charging out of the picture, the next best thing is to charge at work. One of the closest parking lot to my office offers charging under the (ChargePoint)[https://www.chargepoint.com] network, one of the most prominent charging network here at the San Francisco Bay Area. I only have to figure out one thing: How possible it is to have my car charging when I’m at work?

I fired up my browser, typed in their URL. Look! There’s a huge map in the center of the page showing real-time usage of each charging station. I grabbed the network request and open up a new Google spreadsheet – I will need to crawl them every some interval and then plot it.

Much like Excel have the Visual Basic for Applications (VBA) support. The Google Spreadsheet comes with Google Script support: it’s basically JavaScript. It supports network fetching and most importantly, you can set it to run every hour! I happily wrote up some small code to get it started. (P.S. ChargePoint if you are reading this, please don’t send JSON as a GET parameter. It really does not fit.)

It turns out that the charging stations usually become available either before 9am or after 2pm, which given the worst scenario of 4 hours charging time. It’s either I start charging early and move my car in the afternoon or I park early and move my car to charge in the afternoon. Either way, it can be solved by a small detour of my daily routine. I let the data runs for about 2 weeks to confirm that it is the normal and closed the case.

How much are you driving?

This is not just a question that comes up when you’re purchasing an auto insurance. One of the biggest constraint on leasing a car is that it comes with a catch: annual mileage limit. The leaser wants to make sure the residue value they were expecting is not off from the actual value after your lease.