For the past year or so I’ve commented on electric tractor trucks when I see them come up. It has pretty much always been fairly negative for a few simple reasons.

1. Semi transport isn’t actually that big a part of the pie, really. It’s disproportionately popular in the US, right? And even so, its only 20% of the transport CO2 pie, and 1/3rd as much as light trucks and cars. It’s just not that big a priority.
2. Semis have an ENORMOUS amount of energy on board. A fully fueled semi can travel anywhere from 1500-2500 miles. 300 gallons of diesel contain 11.29 MWh, and trucks have the most efficient engines on the road aside from electric cars. Diesel engines can be up to 45% efficient- to match conventional range, a 90% (NB: powerpacks alone are barely 90% efficient) electric truck would need 5.6 MWh of power, almost $3 million across 60 powerpacks. Each power pack weighs 3,800 lbs, and is 86″ high and 52″ wide. Thats 114 tons, and it would fill two trailers. The weight limit on semis is 40 tons, and most states limit them to one trailer. The lifetime cost of a semi is under 2 million. A million dollar truck would increase costs significantly, especially with lost investment opportunity of capital.
3. Semis are incredibly high mileage. They run across the country, and rack up a million miles in under a decade before the engines get rebuilt- 5x farther than a gas car. How would electric batteries match that lifetime?

Well, turns out I was wrong! Tesla is not only working on a semi, they are working on a semi that will have substantial savings. I believe them, so I took another look at my assumptions. Also two dozen people told me I had to be wrong. ANYWAY BACK TO BASICS

ONE REVISITED: Truck transport is actually less popular in the US than in a lot of other countries. Only 3 countries on this graph use more train transport then we do. Since Tesla has built an SUV, its the next biggest untapped category of road vehicle, before pickups. Its the obvious choice, and the difficulty is the only real excuse for not going after it.

TWO REVISITED: Most obviously, power packs are a really bad comparison point to batteries. They are fixed emplacements. The Model S’ battery comprises 16 modules and the frame, armor, cooling, electronics and accessories. Each of those modules is little more than 18650 cells, conductors and some plastic and glue. It’s about the lightest you can expect Tesla batteries to get without new chemistry- 25.4 kg/5.3 kWh. 11 MWh of them would weigh 60 tons, not 114. It isn’t really fair to count the weight of the armor etc with the battery, as it’ll get more efficient at scale and the armor will also be part of the frame. Plus, the electric motor will be more efficient- likely 3x, maybe closer to 4. Hard to say without more information on diesel trucks. So 20 tons, and for the first time my math comes up with a legal battery weight.

Now the biggest mistake I had been making was to assume that the range had to be comparable to a truck. I completely failed to realize that truckers do not drive the full range in a day. In reality, almost all trucks drive less than 800 miles a day, and most trips do not exceed that. The average trip in a truck is only 508 miles. I was surprised to learn that trucks and trains annually move about the same ton-miles. As it turns out, very few expensive things need to move cross country. Finished products are usually close to where they are sold, while raw materials get shipped long distances. An 800 mile electric truck will be quite sufficient to deliver MOST of the things that go on trucks, not just a lot of them. In fact there isn’t much of a reason to go over that if a truck can charge overnight while the operator sleeps. Lowering the range to 800 miles gives an 8 ton battery. Jerome Guillen’s last tractor truck, the Cascadia, weighs 30 tons. 8 tons is practically none of that, especially since pointed out here the engine weighs ~1.5 tons. Removing all the IC components can take the additional weight to around 5 tons, only a 15% increase. Thats practically nothing. In this case, the electric motor weight is nearly negligible.

The price is a lot more reasonable too. We’re down to 1,500 kWh, which at $125/kWh, the estimated price for the Gigafactory’s batteries, is only $190,000. Thats enough to buy two new (low-end) tractor trucks, but its a lot less than 6 million. If tesla can manage to do better than 3x through aerodynamics etc, that brings the price down even more. Regardless, its perfectly plausible for them to build a 250-300k truck.

So electricity will cost ~23 cents per mile at $.12/kWh with these numbers, and diesel will cost ~33 cents per mile. This is pretty high, and thats because of my conservative estimate of efficiency. 13 cents would not be an unreasonable guess for the truck, and that would bring the trucks cost down to ~200k- totally buyable. I’m going to stick with the conservative figure for now. I’m also going to use this study to back up my estimated operating costs. At 1 million miles, the savings would be $100,000, making the electric truck competitive with the most expensive trucks over its lifetime. Meanwhile in theoretically possible land, a 750 kWh truck would pay for itself compared to an average truckand save 150k.

The lifetime cost of an average truck is ~1.6 million. At the most optimistic end, 9.4% savings is nothing to sneeze at. I don’t think I would call it substantial though, especially since you’d be losing out on money by paying all that extra up front. But I think everyone is right, and autopilot is what Tesla is aiming at. Driver wages and benefits are 40% of operating costs, and 38% of overall costs. That’s substantial. I assume it will require legal autopilot driving on the highway.

THREE REVISITED: Semis have very small engines relative to their power. Semi engines run from 300-600 hp (220kw-440kw), which is less than a p85D, with a 17.6x higher capacity. Battery cycle life increases roughly linearly with lowering drain. It’s too hard to guess how much longer the batteries would last like this, but its a LOT. I doubt a million miles will be a problem.

TL;DR: Expect the Tesla tractor truck to cost $200,000-$250,000 dollars and have a 500-800 mile range, somewhere around 1 MWh-1.5 MWh.

Edit: Things that don’t have a big impact:

1. Truck drafting. Trucks driving close in a line saves <10% fuel, or 30k over the life of the truck. Certainly worth it, but not a game changer.
2. Autopilot without legal change. You still need a guy in the truck. You can’t really pay him less because of autopilot. At best, you get <10% due to convoys of trucks.
3. Battery swapping. Battery charging is not the big problem! Charging time sucks, yes, but battery swapping is worse. Its expensive to manage those batteries, and Tesla would have to do it. They really don’t want to. Besides, assuming supercharging to top off your range once a day, you save what? An hour a day? Less? Not a huge deal.
4. Road damage. Electric trucks will not be much heavier overall. They also won’t cause less damage. Road damage is a problem between mass, tires, and the road.
5. Fancy custom trailers. At least, I really doubt it. I may be wrong here as I haven’t looked into it, but I think its too radical a change. If people wont pay the money now for skirts, why would they just because the truck is electric?
6. Short trip trucks. 61% of the money in trucks is in trips <100 miles. At first, that seems great- electric can’t do distance. However 80% of the ton-miles are in >100 mile trips, and thats where electric can compete, on gas prices and on automated highway driving. Short trips are more profitable, but making them electric requires a much higher relative up front cost. Its possible tesla will make a lower capacity truck for these trips, but it will have a whole new set of problems- reduced cycle life, needing extra charging time, etc etc. Much harder, and much less pollution to stop here.
7. Solar Panels. There are ~45 m2 on top of a trailer, about what you might put on a house. The truck uses 45x as much power as a house, though. The very expensive panels would give <5% increase in range.

For the past year or so I’ve commented on electric tractor trucks when I see them come up. It has pretty much always been fairly negative for a few simple reasons.

1. Semi transport isn’t actually that big a part of the pie, really. It’s disproportionately popular in the US, right? And even so, its only 20% of the transport CO2 pie, and 1/3rd as much as light trucks and cars. It’s just not that big a priority.
2. Semis have an ENORMOUS amount of energy on board. A fully fueled semi can travel anywhere from 1500-2500 miles. 300 gallons of diesel contain 11.29 MWh, and trucks have the most efficient engines on the road aside from electric cars. Diesel engines can be up to 45% efficient- to match conventional range, a 90% (NB: powerpacks alone are barely 90% efficient) electric truck would need 5.6 MWh of power, almost $3 million across 60 powerpacks. Each power pack weighs 3,800 lbs, and is 86″ high and 52″ wide. Thats 114 tons, and it would fill two trailers. The weight limit on semis is 40 tons, and most states limit them to one trailer. The lifetime cost of a semi is under 2 million. A million dollar truck would increase costs significantly, especially with lost investment opportunity of capital.
3. Semis are incredibly high mileage. They run across the country, and rack up a million miles in under a decade before the engines get rebuilt- 5x farther than a gas car. How would electric batteries match that lifetime?

Well, turns out I was wrong! Tesla is not only working on a semi, they are working on a semi that will have substantial savings. I believe them, so I took another look at my assumptions. Also two dozen people told me I had to be wrong. ANYWAY BACK TO BASICS

ONE REVISITED: Truck transport is actually less popular in the US than in a lot of other countries. Only 3 countries on this graph use more train transport then we do. Since Tesla has built an SUV, its the next biggest untapped category of road vehicle, before pickups. Its the obvious choice, and the difficulty is the only real excuse for not going after it.

TWO REVISITED: Most obviously, power packs are a really bad comparison point to batteries. They are fixed emplacements. The Model S’ battery comprises 16 modules and the frame, armor, cooling, electronics and accessories. Each of those modules is little more than 18650 cells, conductors and some plastic and glue. It’s about the lightest you can expect Tesla batteries to get without new chemistry- 25.4 kg/5.3 kWh. 11 MWh of them would weigh 60 tons, not 114. It isn’t really fair to count the weight of the armor etc with the battery, as it’ll get more efficient at scale and the armor will also be part of the frame. Plus, the electric motor will be more efficient- likely 3x, maybe closer to 4. Hard to say without more information on diesel trucks. So 20 tons, and for the first time my math comes up with a legal battery weight.

Now the biggest mistake I had been making was to assume that the range had to be comparable to a truck. I completely failed to realize that truckers do not drive the full range in a day. In reality, almost all trucks drive less than 800 miles a day, and most trips do not exceed that. The average trip in a truck is only 508 miles. I was surprised to learn that trucks and trains annually move about the same ton-miles. As it turns out, very few expensive things need to move cross country. Finished products are usually close to where they are sold, while raw materials get shipped long distances. An 800 mile electric truck will be quite sufficient to deliver MOST of the things that go on trucks, not just a lot of them. In fact there isn’t much of a reason to go over that if a truck can charge overnight while the operator sleeps. Lowering the range to 800 miles gives an 8 ton battery. Jerome Guillen’s last tractor truck, the Cascadia, weighs 30 tons. 8 tons is practically none of that, especially since pointed out here the engine weighs ~1.5 tons. Removing all the IC components can take the additional weight to around 5 tons, only a 15% increase. Thats practically nothing. In this case, the electric motor weight is nearly negligible.

The price is a lot more reasonable too. We’re down to 1,500 kWh, which at $125/kWh, the estimated price for the Gigafactory’s batteries, is only $190,000. Thats enough to buy two new (low-end) tractor trucks, but its a lot less than 6 million. If tesla can manage to do better than 3x through aerodynamics etc, that brings the price down even more. Regardless, its perfectly plausible for them to build a 250-300k truck.

So electricity will cost ~23 cents per mile at $.12/kWh with these numbers, and diesel will cost ~33 cents per mile. This is pretty high, and thats because of my conservative estimate of efficiency. 13 cents would not be an unreasonable guess for the truck, and that would bring the trucks cost down to ~200k- totally buyable. I’m going to stick with the conservative figure for now. I’m also going to use this study to back up my estimated operating costs. At 1 million miles, the savings would be $100,000, making the electric truck competitive with the most expensive trucks over its lifetime. Meanwhile in theoretically possible land, a 750 kWh truck would pay for itself compared to an average truckand save 150k.

The lifetime cost of an average truck is ~1.6 million. At the most optimistic end, 9.4% savings is nothing to sneeze at. I don’t think I would call it substantial though, especially since you’d be losing out on money by paying all that extra up front. But I think everyone is right, and autopilot is what Tesla is aiming at. Driver wages and benefits are 40% of operating costs, and 38% of overall costs. That’s substantial. I assume it will require legal autopilot driving on the highway.

THREE REVISITED: Semis have very small engines relative to their power. Semi engines run from 300-600 hp (220kw-440kw), which is less than a p85D, with a 17.6x higher capacity. Battery cycle life increases roughly linearly with lowering drain. It’s too hard to guess how much longer the batteries would last like this, but its a LOT. I doubt a million miles will be a problem.

TL;DR: Expect the Tesla tractor truck to cost $200,000-$250,000 dollars and have a 500-800 mile range, somewhere around 1 MWh-1.5 MWh.

Edit: Things that don’t have a big impact:

1. Truck drafting. Trucks driving close in a line saves <10% fuel, or 30k over the life of the truck. Certainly worth it, but not a game changer.
2. Autopilot without legal change. You still need a guy in the truck. You can’t really pay him less because of autopilot. At best, you get <10% due to convoys of trucks.
3. Battery swapping. Battery charging is not the big problem! Charging time sucks, yes, but battery swapping is worse. Its expensive to manage those batteries, and Tesla would have to do it. They really don’t want to. Besides, assuming supercharging to top off your range once a day, you save what? An hour a day? Less? Not a huge deal.
4. Road damage. Electric trucks will not be much heavier overall. They also won’t cause less damage. Road damage is a problem between mass, tires, and the road.
5. Fancy custom trailers. At least, I really doubt it. I may be wrong here as I haven’t looked into it, but I think its too radical a change. If people wont pay the money now for skirts, why would they just because the truck is electric?
6. Short trip trucks. 61% of the money in trucks is in trips <100 miles. At first, that seems great- electric can’t do distance. However 80% of the ton-miles are in >100 mile trips, and thats where electric can compete, on gas prices and on automated highway driving. Short trips are more profitable, but making them electric requires a much higher relative up front cost. Its possible tesla will make a lower capacity truck for these trips, but it will have a whole new set of problems- reduced cycle life, needing extra charging time, etc etc. Much harder, and much less pollution to stop here.
7. Solar Panels. There are ~45 m2 on top of a trailer, about what you might put on a house. The truck uses 45x as much power as a house, though. The very expensive panels would give <5% increase in range.

For the past year or so I’ve commented on electric tractor trucks when I see them come up. It has pretty much always been fairly negative for a few simple reasons.

1. Semi transport isn’t actually that big a part of the pie, really. It’s disproportionately popular in the US, right? And even so, its only 20% of the transport CO2 pie, and 1/3rd as much as light trucks and cars. It’s just not that big a priority.
2. Semis have an ENORMOUS amount of energy on board. A fully fueled semi can travel anywhere from 1500-2500 miles. 300 gallons of diesel contain 11.29 MWh, and trucks have the most efficient engines on the road aside from electric cars. Diesel engines can be up to 45% efficient- to match conventional range, a 90% (NB: powerpacks alone are barely 90% efficient) electric truck would need 5.6 MWh of power, almost $3 million across 60 powerpacks. Each power pack weighs 3,800 lbs, and is 86″ high and 52″ wide. Thats 114 tons, and it would fill two trailers. The weight limit on semis is 40 tons, and most states limit them to one trailer. The lifetime cost of a semi is under 2 million. A million dollar truck would increase costs significantly, especially with lost investment opportunity of capital.
3. Semis are incredibly high mileage. They run across the country, and rack up a million miles in under a decade before the engines get rebuilt- 5x farther than a gas car. How would electric batteries match that lifetime?

Well, turns out I was wrong! Tesla is not only working on a semi, they are working on a semi that will have substantial savings. I believe them, so I took another look at my assumptions. Also two dozen people told me I had to be wrong. ANYWAY BACK TO BASICS

ONE REVISITED: Truck transport is actually less popular in the US than in a lot of other countries. Only 3 countries on this graph use more train transport then we do. Since Tesla has built an SUV, its the next biggest untapped category of road vehicle, before pickups. Its the obvious choice, and the difficulty is the only real excuse for not going after it.

TWO REVISITED: Most obviously, power packs are a really bad comparison point to batteries. They are fixed emplacements. The Model S’ battery comprises 16 modules and the frame, armor, cooling, electronics and accessories. Each of those modules is little more than 18650 cells, conductors and some plastic and glue. It’s about the lightest you can expect Tesla batteries to get without new chemistry- 25.4 kg/5.3 kWh. 11 MWh of them would weigh 60 tons, not 114. It isn’t really fair to count the weight of the armor etc with the battery, as it’ll get more efficient at scale and the armor will also be part of the frame. Plus, the electric motor will be more efficient- likely 3x, maybe closer to 4. Hard to say without more information on diesel trucks. So 20 tons, and for the first time my math comes up with a legal battery weight.

Now the biggest mistake I had been making was to assume that the range had to be comparable to a truck. I completely failed to realize that truckers do not drive the full range in a day. In reality, almost all trucks drive less than 800 miles a day, and most trips do not exceed that. The average trip in a truck is only 508 miles. I was surprised to learn that trucks and trains annually move about the same ton-miles. As it turns out, very few expensive things need to move cross country. Finished products are usually close to where they are sold, while raw materials get shipped long distances. An 800 mile electric truck will be quite sufficient to deliver MOST of the things that go on trucks, not just a lot of them. In fact there isn’t much of a reason to go over that if a truck can charge overnight while the operator sleeps. Lowering the range to 800 miles gives an 8 ton battery. Jerome Guillen’s last tractor truck, the Cascadia, weighs 30 tons. 8 tons is practically none of that, especially since pointed out here the engine weighs ~1.5 tons. Removing all the IC components can take the additional weight to around 5 tons, only a 15% increase. Thats practically nothing. In this case, the electric motor weight is nearly negligible.

The price is a lot more reasonable too. We’re down to 1,500 kWh, which at $125/kWh, the estimated price for the Gigafactory’s batteries, is only $190,000. Thats enough to buy two new (low-end) tractor trucks, but its a lot less than 6 million. If tesla can manage to do better than 3x through aerodynamics etc, that brings the price down even more. Regardless, its perfectly plausible for them to build a 250-300k truck.

So electricity will cost ~23 cents per mile at $.12/kWh with these numbers, and diesel will cost ~33 cents per mile. This is pretty high, and thats because of my conservative estimate of efficiency. 13 cents would not be an unreasonable guess for the truck, and that would bring the trucks cost down to ~200k- totally buyable. I’m going to stick with the conservative figure for now. I’m also going to use this study to back up my estimated operating costs. At 1 million miles, the savings would be $100,000, making the electric truck competitive with the most expensive trucks over its lifetime. Meanwhile in theoretically possible land, a 750 kWh truck would pay for itself compared to an average truckand save 150k.

The lifetime cost of an average truck is ~1.6 million. At the most optimistic end, 9.4% savings is nothing to sneeze at. I don’t think I would call it substantial though, especially since you’d be losing out on money by paying all that extra up front. But I think everyone is right, and autopilot is what Tesla is aiming at. Driver wages and benefits are 40% of operating costs, and 38% of overall costs. That’s substantial. I assume it will require legal autopilot driving on the highway.

THREE REVISITED: Semis have very small engines relative to their power. Semi engines run from 300-600 hp (220kw-440kw), which is less than a p85D, with a 17.6x higher capacity. Battery cycle life increases roughly linearly with lowering drain. It’s too hard to guess how much longer the batteries would last like this, but its a LOT. I doubt a million miles will be a problem.

TL;DR: Expect the Tesla tractor truck to cost $200,000-$250,000 dollars and have a 500-800 mile range, somewhere around 1 MWh-1.5 MWh.

Edit: Things that don’t have a big impact:

1. Truck drafting. Trucks driving close in a line saves <10% fuel, or 30k over the life of the truck. Certainly worth it, but not a game changer.
2. Autopilot without legal change. You still need a guy in the truck. You can’t really pay him less because of autopilot. At best, you get <10% due to convoys of trucks.
3. Battery swapping. Battery charging is not the big problem! Charging time sucks, yes, but battery swapping is worse. Its expensive to manage those batteries, and Tesla would have to do it. They really don’t want to. Besides, assuming supercharging to top off your range once a day, you save what? An hour a day? Less? Not a huge deal.
4. Road damage. Electric trucks will not be much heavier overall. They also won’t cause less damage. Road damage is a problem between mass, tires, and the road.
5. Fancy custom trailers. At least, I really doubt it. I may be wrong here as I haven’t looked into it, but I think its too radical a change. If people wont pay the money now for skirts, why would they just because the truck is electric?
6. Short trip trucks. 61% of the money in trucks is in trips <100 miles. At first, that seems great- electric can’t do distance. However 80% of the ton-miles are in >100 mile trips, and thats where electric can compete, on gas prices and on automated highway driving. Short trips are more profitable, but making them electric requires a much higher relative up front cost. Its possible tesla will make a lower capacity truck for these trips, but it will have a whole new set of problems- reduced cycle life, needing extra charging time, etc etc. Much harder, and much less pollution to stop here.
7. Solar Panels. There are ~45 m2 on top of a trailer, about what you might put on a house. The truck uses 45x as much power as a house, though. The very expensive panels would give <5% increase in range.