Thursday, April 21, 2022

How many ebikes in an electric car?

I got a real bike in September of last year. “Real bike” means a bike from a bike shop, and not a Walmart bike. Nothing against Walmart bikes, which while cheap and generally of low quality, are a great way to get into cycling without spending a lot of money. Getting a bike was on my list of things to do for a while but a friend finally convinced me to buy one, so I did. 

The bike is not the point of this post, but I’m starting with it because it’s a good introduction and transition to the topic of this blog post. So, bear with me as I talk a little bit more about the bike.

I’ve been riding it around town and exploring the back rounds that surround it and it’s a lot of fun. In particular, a nice highway runs between my town and the neighboring town. It is somewhat bike friendly (bike friendly is super generous for what it is, but more on that in a later post), meaning it has a large shoulder and has two lanes in each direction, so nice drivers will leave a lane between me and them, and not so nice drivers still have some separation. 

When I feel like going on a low effort ride on a relatively straight and flat road, I will ride here. This road runs right next to a small town which has a fairly large Mennonite population. The Mennonites here like to ride horse and buggies, and bicycles, so seeing them on their preferred modes of transportation is pretty common. 

I was riding on this road once and behind me I saw a cyclist. Cool, I thought. It’s always nice to see another cyclist on the road. I didn’t get a good look at them and they were a fair distance behind me, so I figured there was a good chance I wouldn’t meet them. Much to my surprise, a minute or two later, she passed me! I was able to get a good look at her bike and it was definitely an ebike, and by her dress, I was pretty sure she was a Mennonite.

Let me define ebike very quickly: it is mostly a normal bicycle. It has pedals. But it has a battery mounted somewhere in or on the frame, and a small electric motor in either the crank or the back wheel. The electric motor just assists your pedaling, helping you move faster and use less effort when riding, such as up a hill. To be clear, an ebike as referred to here is not an electric motorcycle or a moped. It is simply a bicycle with pedals but also with an electric assist. If the battery were dead, you could ride it like a normal, although somewhat heavy, bicycle.

I had talked to my coworker a few times previously about riding my bike and he was saying how Mennonites are really quick on their bikes because they cycle so much, so they have really strong legs. And I told him that based on the single piece of data I observed, Mennonites ride ebikes, implying that that’s how they are able to cycle so quickly. And he said that was impossible because Mennonites don’t use technology, and if they’re willing to use an ebike, what’s wrong with an electric car?

I’m not sure how true it is that Mennonites don’t use technology. A quick Wikipedia search yields the answer “it depends”. But that’s not the point. The point is the question of the equivalence of the ebike and the electric car.

Electric cars have been heralded as one of the great tools in our battle against climate change. If everyone were using electric cars, tailpipe emissions would be eliminated, and the greater efficiency would mean that power plants are generating the energy required for transportation while generating fewer emissions than all the gasoline and diesel engines that would have been on the road otherwise.

Some weeks later I was talking to another coworker and this topic came up. I told him it’s not right to think of an electric car as equivalent to an ebike. The car takes vastly more resources to manufacture and run than a bike. I told him if you took the battery pack out of an electric car (which is made up of many cells), and split up those cells into a typical ebike, you would get this many ebikes. (I will reveal the number later). And it’s a big number.

I decided to message another coworker the following question: 

If you took the battery pack out of an electric car, say a Tesla Model S, and split up the cells into ebikes (pedal powered bicycle with electric assist), how many ebikes would you be able to make? Don't think about it too hard and don't look it up. I'm curious what your first guess is.

I then figured, might as well question the entire room. So I went through the whole room (on Microsoft Teams) and asked the question. I also asked our sister office about 2 hours away. I got approximately 30 answers like this. Then I went through everyone I had texted recently. The next time I was at the brewery I asked the bartenders, and the people sitting next to me. As of now, I have 84 responses.

I spent some time thinking about how best to visualize this and this is what I came up with. Here is a plot of each answer and the frequency of that answer.

Here are some 5th grade statistics:

Mean: 312

Median: 50

Mode: 100

The mean is a bit skewed by the few very high guesses. I think the median is the most accurate representation of the data. The mode is pretty good too. But overall, the guesses were pretty low, less than 50 ebikes per electric car. 

Obviously, the correct answer will vary depending on a lot of variables. Teslas tend to have larger batteries than other electric cars, such as the Nissan Leaf. And of course there is a huge range in ebikes, from light recreational bikes to larger cargo bikes. But here’s a calculation for an approximate answer:

According to Wikipedia, a P85 Model S contains 7104 battery cells. The type of cell (like AA or AAA) is “18650”, which simply means it is a cylinder with diameter 18 mm and length 65 mm. An ebike might have between 15 and 20 of these 18650 cells. Some simple division, and you get a ballpark of 400 ebike batteries for a single Model S. 

When I first learned this, I was astonished. I would have guessed the true answer was somewhere between 20 and 30. I was very surprised to find out that one could get 400 ebike batteries from a single electric car battery!

The purpose of this question was to get an idea for peoples’ intuition for how big an electric car battery is. Most people haven’t seen one and haven’t driven an electric car, and so won’t really have a basis for making an estimate. This is fine. The idea was to see what people think without knowing any of the numbers. I think it is easy to conclude that most people, including myself, vastly underestimate its size. An electric car battery is simply massive. You might have seen an ad for the Ford F-150 lightning, which has enough power to run your house for a few days.

The obvious follow up question to this is, are electric cars really the answer to our transportation problem when the resources required to transport a single person (or 5 if it’s fully occupied) in an electric car can be used to transport 400 people? Four hundred people!

I know what you’re thinking: How can someone commute to work on an ebike? You can’t expect people to complete their 20 or 30 mile commute on the highway or interstate on an ebike. What about getting groceries or going shopping? What about weather? What if it’s cold or hot or raining or snowing? Do you seriously think we can give everyone an ebike, take away their car, and not expect riots in the streets?

But you have to wonder, are electric cars really a crucial and necessary component in our fight against climate change? Or do they exist just to save the automobile industry?

These are questions I hope to address in future blog posts. 

However, the plan for this blog is not to discuss electric cars or climate change. Rather, I want to explore the dominance of the automobile in influencing the design of human spaces in North America. 

I was inspired by this topic after I started riding a bike. Once I started exploring the world on two wheels rather than in a metal cage on four, I began noticing all the ways in which the space we live in is designed around the automobile, and how unfriendly it is once you leave it. We take our car dependence, and all the other aspects of our lives that go along with it for granted, but is this really the best we can do? Is there something better? Are there other places that have already figured this out? I think the answer is yes, there is something better. But more on that later.

This is more for myself rather than you the reader, but the following are some ideas for future blog posts addressing this question:

  1. The dominance of car infrastructure, at the expense of “human infrastructure”, in North America.
  2. Cars and the energy problem. Weight and velocity.
  3. The greatest contributors of carbon emissions in modern society.
  4. What does it really mean to have cycling infrastructure?
  5. Lithium battery manufacturing. Is it really green?

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