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Thursday, July 27, 2017

Tesla Semi Speculation

Battery swap, solar roof, conveyor floor, glass cab, and more. Tesla has an opportunity to reinvent the semi truck.

Tesla is known for their fast, luxury, long-distance EVs. This month they are shipping their mass production Model 3 and branching into a new market. This fall they will be showing off their new venture into semi trucks.

Tesla has scheduled the big reveal event for their all-electric heavy-duty long-haul semi truck in September of this year. Until this event, we are not likely to know much about the vehicle. Let's look at the market requirements and see if we can use this and what we know about Tesla's first principles approach to make some guesses about the Tesla Semi. Then, for fun, we'll round out the list with some things that would be cool to see.

Tesla Semi - What We Know

Elon Musk has said few things already, “It is a heavy duty, long range, semi-truck. So it has the highest weight capability and with long range. So essentially it’s meant to alleviate the heavy duty trucking loads.”

Musk says it will be heavy duty, how heavy? He said it will be long range, how long? Below we'll try to put bounds on these superlatives.

Musk continues, “And this is something which people do not, today, think is possible. They think the truck doesn’t have enough power or it doesn’t have enough range. And then with those with the Tesla semi we want to show that no, an electric truck actually can out-torque any diesel semi and if you had a tug-of-war competition, the Tesla semi what will tug the diesel semi uphill.”

How Long Is Long Range?

How far will Tesla's semi truck need to go on a single charge?

Eventually, Tesla's semi will be fully autonomous, but for now, let's assume that they will be human-piloted and they will need to conform to the national laws for semi driving. Here are some of the relevant US laws:
Legal drive time is 11 hours of driving with 10 hours of break thereafter. Additionally, drivers are restricted to 70 hours in an 8 day period.  via TruckersReport.com
Driving for 11 hours at 60 MPH is 660 miles of range. At first glance, this seems like an impossible range. It's more than double the range of Tesla's longest-range vehicle on the roads today. Is it possible? For comparison, consider that BYD has a 60-foot bus with a 270-mile range. To achieve this, they use a 547 kWh battery pack. Assuming Tesla's semi would have a similar efficiency as the bus, the semi would need about 1300 kWh in its battery pack to achieve a 660-mile range. That is the equivalent to 13 packs in a Tesla Model S 100. That is a massive battery pack, but not impossible.

How Heavy is "Heavy Duty"? 

In the trucking industry, heavy duty generally means Class 8. A Class 8 truck has a total weight limit of 80,000 pounds. Typically the load maxes out at 40,000 pounds with the truck itself weighing at ~35,000 pounds.

By this definition, a Tesla semi would need to be capable of carrying the same 40,000 pounds of payload.

Based on the few scraps of information that we have, to be considered long-range and heavy duty, our best guess is that this vehicle will be capable of 600+ miles range and 40,000 pounds of payload.

Tesla has reinvigorated the auto industry. The trucking industry is now on their radar. What other cool things might Tesla do in the semi truck space.


Trailer 2.0

The trailer that semis pull has been generally ignored by the industry. It is just something that the truck connects to. It has been an idle passenger. Tesla could change this.

What if the trailer had motors of its own. We know that the Tesla semi will be using “a bunch” of Model 3 electric motors. If these are placed on the trailer as well as the truck, there are a lot of cool things the trailer could do.

18-Wheel All-Wheel-Drive

If Tesla is going to use the Model 3 motors, it will need several of them. Putting them on the trailer as well as in the semi would allow for more power and control. This makes the trailer a vital part of the vehicle system. 

Once the trailer has its own motors, it makes sense for it to have its own batteries too. If they are going to put 13 cars worth of batteries someplace, the floor of the trailer seems like a place with ample room. 

Trailer Summons & Tank Turns

Now that the trailer has its own motors and batteries, there are many more cool things that could be done with the trailer. Imagine a yard where the trailers can be summoned. To do this, the trailer would need its own camera system, so let's put 8 or more cameras around the trailer. 

With the independent motors, the trailer would be able to move in ways that are impossible when they are being towed by a semi. For example, they could turn in place like a tank. This would allow for maneuverability that is important in crowded yards to move to loading docks and connection points. 

Trailer As Battery Swap

Tesla has tried battery swap before and some people have speculated that the idea will be resurrected for the semi truck. To me, it seems unlikely that they will retrace this ground, at least not in the same way.

Above we have two assumptions: one, the vehicle will have a ~1300kWh pack and, two, some (perhaps a majority) of these batteries will be in the trailer. If these assumptions (or something like them) turns out to be true, then here's an interesting possibility: What if a driver could pull into a loading dock, drop off a trailer with a depleted battery, hook up to a trailer with a fully charged battery and get back on the road. Depending on the split of the battery pack (say 350/950), this could restore a majority of the vehicle's charge in just a few minutes.

If the load needs to be transferred from the depleted trailer to the charged trailer, there are many options. With a flatbed, the cargo could be stored in a standard shipping container, then moved from trailer to trailer with a crane. Another option would be for the Tesla trailers position themselves next to each other and to have a conveyor floor on the trailer to slowly transfer the container from one trailer to the other.

Solar Roof (and sides)

On a car, you don't have a large roof and solar is just not that effective at adding significant range to the vehicle. You are far better off spending that money to put solar on your home, if you are interested in powering your commute with the sun. A semi truck is another story.

The conveyor floor mentioned above is an option for flatbeds, but there are other options for enclosed trailers (dry vans, and refrigerated trailers/reefers). An enclosed trailer is typically 45 to 53 feet long and the width is 92 to 98 inches wide. For a larger trailer, this is over 400 sq ft; that's a large roof, large enough to put about 8kW of solar panels on the roof.

Depending on the sun exposure, this could add 40 miles of range to the battery pack each day. For refrigerated trailers, these solar panels could be used to keep the contents cool without depleting the range of the truck.

They are less optimally angled to the sun, but solar panels on the side would add more energy. Would that make it a panel van? ☺

Semi 2.0 Misc.

I'm sure Tesla will have some surprises for us in September. Tesla is known for their glass roofs. The Model X has the largest windshield of any passenger vehicle currently in production. We are likely to see a plentiful use of glass on the semi too. The big screen that Tesla is known for will also likely be in the semi with a new utility. The cameras that surround the cab and trailer could also give the driver a view of the lane next to them or a view of blind-spots.

What other things could this trailer include:
  • Air suspension - this would raise and level the trailer to align it to loading dock platforms. This is a common feature in many trailers. Loading docks are typically anywhere from 48 to 52 inches high. Tesla has air suspension in the Model S & X, the semi and trailer will likely have it too. 
  • Ramp - Ramps and lift gates are common features in many trailers today. Tesla is likely to have these options too, but what innovation twist might they add? 

Market Size

About 250,000 semi truck cabs are sold in the US each year. And the US is just one of many markets of course. The average selling price for a cab is ~$155,000. Tesla's semi is likely to cost much more than this, but it will be far cheaper to fuel and there will be far less maintenance. Fleet owners are generally more concerned with the total cost of operation. Lower fuel and maintenance costs would give them headroom for a higher monthly vehicle payment. And after the vehicle is paid off, they will still enjoy the lower monthly fuel bill and increase their profit for moving goods. 

Wrap Up

This is highly speculative, but it's fun to guess. We'll learn more in September and there may be some more hints in the quarterly financial calls or Musk's tweets. We'll see if any of these guesses turn out to be accurate.

Saturday, July 15, 2017

The Ultimate Nerd Road Trip 2017


This summer I'll be taking the Model X on several road trips. One of them I've dubbed The Ultimate Nerd Road Trip 2017.

It's a road trip from Portland, OR to San Diego to attend Comic-Con. I've never been to Comic-Con. This should be fun. A friend and I are leaving from Portland. After a few charging stops, we'll arrive in San Jose to pick up our third amigo. After a night in San Jose, all three of us will continue south the next morning.

We'll spend several days at the con and in San Diego then head back north. While we're heading back, we have scheduled a tour of the Tesla factory in Fremont.

This will be my longest road trip in the Tesla Model X. I've made a page on facebook where I'll be posting photos and updates from the road, the con, and the factory (at least as much as the NDA allows). If you'd like to follow my trek, like the page here.

Monday, July 10, 2017

The 80-20 Rule of EV Driving


The Pareto Principle or as it's better know, the 80-20 Rule, has been applied to many things. The principle says that 80% of a business's sales come from 20% of their customers and that 80% of revenue is from only 20% of the products offered. The generalized version says 80% of results come from 20% of the causes. Among the things this rule of thumb has been applied to include wealth distribution, spending habits, and even infidelity.

80% of Driving Needs

Since this principle has such broad applications, I started wondering how this might apply to EV driving and charging. In the How Much Range Is Enough story<<Link TBD>>, we looked at how much range your EV would need. One of the big factors is will the EV be your only car? If so, how easy is it for you to make other arrangements if it will not work for you?... For most people, it is relatively easy to find an EV that will meet 80% of your driving needs. Almost no vehicle meets 100% of a person's transportation needs. So the question is, how much are you willing to pay for something that meets 90, 95, or 99% of your needs.

80% Charge

The first similarity is that 80% of a batteries capacity can quickly charge. Whereas the charging rate slows down for the last 20% of the charge. Technically, I don't think this is an application of the Pareto Principle, but it is an 80-20 rule for batteries.

Daily Drives

On any given day, about 80% of people drive less than 40 miles. For a long-range (200+ mile) EV, forty miles of driving will use about 20% of the capacity. There are multiple uses of the 80-20 rule here.

It's less wear and tear on lithium batteries to move energy in and out in the middle 60% of a batteries capacity. This is the reason that long range EVs have a trip mode and a daily driving mode. If the principle holds, 80% of the miles driven and kWh used, will come from the top of this daily drive region of the battery charge range.

Range Anxiety

When you have less than 20% charge left, you might start getting concerned that you could become stranded with a drained battery. This means that 80% of your battery is comfortably usable. Of course, this number is different for every person, but this is a good rule of thumb.

Home Charging / Public Charging

The Idaho National Lab studied 125 million miles of EV driving. The study included 6 million charging events. They found that 20% of drivers were responsible for 75% of public charging events. The other 80% of drivers charged primarily at home and rarely if ever used public charging.

What Can We Learn

There are many lessons to be learned from the patterns of charging and battery use. For example, the fact that most charging is done at home could teach us that efforts to pre-wire garages with high amperage 240 Volt outlets would encourage EV ownership better than deploying Level 2 public charging stations. Similarly, deploying charging infrastructure in multi-tenant dwellings may be the best way to allow apartment and condo dwellers to also become plug-in vehicle owners. This is just something that the data hints at and more study would be needed to confirm or reject this, but it seems intuitive that making home charging easy would make EV ownership simpler and more attractive.

Wednesday, July 5, 2017

When Will Tesla Hit 200,000 Sales in the U.S.? [Q2 2017 Update]


We've been tracking Tesla's sales for some time now. Specifically, the sale of the 200,000th vehicle in the US is an important milestone since it will trigger the US Federal incentive to begin a phase out 3 to 6 months later.

There are hundreds of thousands of people with Model 3 reservations, the timing of the incentive phase out could impact many buyers, so it's an important question.

Earlier this month, Tesla released their Q2'17 sales numbers. They have now sold more than 130,000 vehicles in the US. The Q2 sales numbers were slightly lower than we predicted three months ago and lower than the Street expected and the stock price was punished accordingly. Although the Street was not happy with the Q2 sales, these lower than expected sales did not impact the 200,000th sale forecast significantly.

Here are the historical sales and our forecast.


Just as our forecast from 3 months ago, this new forecast predicts that the 200,000th US sale will occur in the second quarter of 2018. If that is the case, the incentive will phase out as shown in the below image.


Tesla Model 3 sales start with a token amount this month and depending on how fast they ramp, this forecast could change significantly. We'll have a much better idea where the 200,000th sale will likely fall by the end of this year.

Assuming that the above forecast is correct, the incentive would remain in full effect until the end of September of 2018. This would afford Tesla more than one year of Model 3 deliveries that would be fully eligible for the US tax incentive. This should include delivery of the dual motor all-wheel-drive and performance versions of the cars that are expected to start delivery in early 2018. So if you already have a reservation, there is a good chance that you could have your car in time to qualify for the $7500 federal tax credit.

Monday, July 3, 2017

Tesla Model 3 Countdown Begins


Thanks to a tweet from Elon Musk, we now have a date for the Model 3 event and it's the 28th of July. The first Model 3 owners will be handed their keys by Elon Musk on stage.

From the Tesla investor newsletter, we have even more details about the Model 3.
The first certified production Model 3 that meets all regulatory requirements will be completed this week...
Combining the above with Musk's statement that this is two weeks ahead of schedule and we can see that, so far, things appear to be on schedule for Model 3.


Other things we learned from Elon's tweets include, "looks like we can reach 20,000 Model 3 cars per month in Dec." Depending on how fast the ramp to 20,000 occurs, this likely puts the year's production in line with our earlier estimate.

My factory tour is scheduled for July 25th. I might be able to see some of the first full production Model 3s to be produced.

EV Range: How Much Is Enough?


With the Chevy Bolt EV hitting the sales floor, the affordable 200+ mile EV has arrived. The Tesla Model 3 will be arriving soon with two battery options that are greater than 200 miles. Nissan, BMW, and others are, at least for now, are sticking to EVs in the sub-200 miles of range category. Who is right? Which will customers choose?

How much range is enough?

I've owned three EVs with vastly different ranges. In an attempt to answer the 'how much range is enough' question, I'll compare my experience with these EVs. My first EV had 40 miles range and I drove it for 4 years. My second had 73 miles of range and it was my primary vehicle for 5 years. And my current EV has 257 miles of range. Each vehicle had cases where it worked well and cases where it didn't work well.

Before we get into this too far, I'd like to clarify that there is no "one right answer" for range. Everyone has different needs, so the trick is to understand your own needs. Try resetting your trip meter, then each morning noting how many miles you have from the day before, then zeroing it again for the days driving. This will give you a good idea of your needs for a typical day. You might find that you don't drive as much as you think.

A note about what's right for you. When I was first shopping for an EV in 2007, I found a little 3-wheeled Chinese import EV. I went for a test drive. I was not impressed. It was slow, it had a short range. I complained about the slow speed and low range on a local EV mailing list. I was gently informed that I should end all of my complaints with "for my needs." As in "It is too slow for my needs." The gentle soul responding to me went on to say that she had one of these EVs and it worked great for her needs. She lived in a gated retirement community and it had more than enough range to get her to the clubhouse, her friends, the corner store, and more. She ended it with "Mankind got around for many years on one-horse-power. It had four legs and was called a horse."

So with that in mind, I'll tell you about my experience with each of my various EVs I've owned and how the range impacted my ability to use (or not use) them. Your mileage may vary. The best EV for you is one that meets your personal needs, so spend some time understanding them, open a map app and chart out the places you drive regularly.

Infographic from Plugless shows how far you could drive in various EVs on the market today

Let's look at each of the ranges and the driving experience with them. 

40 Miles Range

My first EV was a Chevy S10 Electric truck. This was not a conversion. It's the little-known cousin of the GM EV1. General Motor had leased most of these truck, just as they had the EV1, but these trucks were intended as fleet vehicles. Some fleet managers refused to lease. They wanted to buy the trucks. GM reluctantly sold them. The Air Force bought some, a Georgia utility bought some, and mine came to me after it retired from service at Disneyland.

I drove this truck from 2007 until 2011. The S10e was only built in 1997 and 1998. There was a lead acid battery pack option with 16.2 kilowatt-hours of capacity or a nickel–metal hydride pack with 29 kilowatt-hours. By the time I owned the truck, the 19-year old nickel–metal batteries had severely degraded. The 40 miles of range they had remaining allowed me to drive to work and back (20 miles round trip) and run errands, but little else. Although similar batteries were being used in many hybrid cars, the restrictions put in place by the patent holder (Chevron) did not allow anyone to sell me batteries for a BEV, or so I was told repeatedly as I called dealerships and attempted to order batteries.

Given the 40 miles of range, the truck was relegated to my commuter vehicle. This was a fixed, well-known route. It worked well for the 20-mile round trip with a little extra to spare for errands on the way home. The truck bed was nice for jaunts to Home Depot (15-mile round trip). This was not a vehicle that I could drive someplace on the spur of the moment. I had to know where I was going and make sure that I could make it back.

40 Miles Is Good For: short commutes, errands, well-defined short trips.

73 Miles Range

In 2011, I sold the electric truck and bought a Nissan Leaf. Our Leaf had an EPA-rated range of 73 miles. This was nearly double the range of the truck. And the Leaf had a DC fast charge port. This opened up many more destinations for electric driving. With the charging spots of the West Coast Electric Highway, this was range was enough for trips within ~120-mile radius.

You might wonder if the car can fast charge, why I would limit it a fixed radius. At freeway speeds, the range is reduced, so you have to charge every 40 or 50 miles and too many back-to-back fast charges heats up the batteries and slows down the charging rate. Longer trips certainly are possible and have been done, but I would call a ~120 miles the practical limit.

There are those that would argue the above paragraph. But for me, it's what I've found to be true. Here is a story of one of our ~100-mile trips. We drove our Leaf 110 miles to Great Wolf Lodge. The EPA rated range does not hold true at freeway speeds. This meant that we had to stop three times to drive our "73-mile" vehicle just 110 miles. We might have been able to skip one of the chargers, but we didn't know if each station would be online or available. So until the final leg, we didn't let the charge get too low so we could keep going if one of the stations was down or blocked. This added about an hour to our otherwise 2-hour drive. Adding 30% time to the trip is not how I would want to take to take a 500 mile+ trek.

There should be a metric for charging overhead. E.g. for every 10 hours of 65MPH driving you need X hours of charging (at the vehicle's fastest rate).

73 Miles Is Good For: longer commutes (60 miles round trip or less), urban driving, short treks (120-mile or less) if you have DC fast charging available.

257 Miles Range

Six months ago, I began driving my third and longest range EV, a Tesla Model X. Ours is a 90D and it has an EPA rated range of 257 miles. This is by far the best (and most expensive) vehicle that I've ever owned. Rather than becoming distracted by some of the many great features, I'll stick to the range topic.

This is the vehicle that I drive to and from work. It can handle with no trouble and if I forget to plug in, even for several days, it is still ready to go and I don't have to worry about running out of charge.

We have made three treks in this vehicle. Two of them were from Portland, OR to Grants Pass and back. This is ~250 miles one-way, a four-hour drive. Again, with freeway speeds and the Cascade mountains, the EPA range does not hold true. This is solved by using the Tesla Supercharger network. We made one stop in Springfield for 25 minutes. This charging stop only added 10% to drive time. This is much better than the 30% addition to our trip time with the Leaf.

Our third trek was to the Oregon coast. This was a two-hour, 80-mile drive. We left the house with a full charge and arrived with more than a 40% charge. There was no need to stop and charge during the drive. This was nice. Again high speeds and mountain climbing (this time the coast range) meant that we did not meet the EPA rated distance. There are Tesla Superchargers on the Oregon coast, so one of the mornings that we drove into town for breakfast, we stopped at one of the Superchargers for 15 minutes to grab a few watt-hours.

This summer, when we are pulling our trailer, I might be hoping for another 20 or 30 kWh. But that is a story for another day.

Wrap Up 

More range makes everything easier. You don't have to budget the kWhs as carefully. Using 5 kWh for heat or AC is not a big deal from a 90 kWh pack like it is from a 24 kWh pack. If a charging station is down or blocked, you can likely continue down the road and charge at the next opportunity.

Of course, the drawback is the price. There is a big price difference between 30, 50, or 70+ kWh vehicles. Given this, it is important that you know what range you really need and how much you are willing to pay for the convenience and utility of more batteries.