You can’t simply look at the power output of a petroleum tractor and convert that to the equivalent electric tractor. Even though the electric tractor may be more efficient, other inputs such as fertilizer are less efficient when they’re made without petrochemical inputs.
When you look at our industrial civilization, all the critical resource flows are basically running on very high power equipment. That’s stuff like ships, trucks, trains, tractors, airplanes, construction equipment, rockets, heavy machinery etc.
For any of those things to work, they require very large amounts of power and a very good weight to power relationship.
None of these seem to have any serious technical substitute. Notice there are no obvious “green” versions of any of these devices. You can do some of the things more efficiently, but apparently you cannot substitute for the power required.
A green tractor that has a battery big enough to replace the power of a diesel motor will sink into the dirt and not have the traction needed. It will be too big and heavy. A battery big enough to pull a semi trailer a good distance weighs as much as the loaded trailer, etc. A battery airplane is too heavy to lift a cargo and fly to another continent. Etc.
Diesel is around 35X as energy dense as batteries on a watts / kg basis.
A gallon of diesel has as much energy as a 200lb battery. So when a semi takes 150 gallons, that would be a 30,000 lb. battery. If the electric motor is twice as efficient, it’s still a 15,000lb battery. A semi pulls 50,000lbs max…
Think of the system now. If every single semi loses 30% of its towing capacity, sure the motors can be more energy efficient but you might need 30% more trucks to do the work. At some point we have 500 horses instead of 1 locomotive. It’s not really a clear advantage.
You can’t simply look at the power output of a petroleum tractor and convert that to the equivalent electric tractor. Even though the electric tractor may be more efficient, other inputs such as fertilizer are less efficient when they’re made without petrochemical inputs.
That’s pretty much exactly my thought.
When you look at our industrial civilization, all the critical resource flows are basically running on very high power equipment. That’s stuff like ships, trucks, trains, tractors, airplanes, construction equipment, rockets, heavy machinery etc.
For any of those things to work, they require very large amounts of power and a very good weight to power relationship.
None of these seem to have any serious technical substitute. Notice there are no obvious “green” versions of any of these devices. You can do some of the things more efficiently, but apparently you cannot substitute for the power required.
A green tractor that has a battery big enough to replace the power of a diesel motor will sink into the dirt and not have the traction needed. It will be too big and heavy. A battery big enough to pull a semi trailer a good distance weighs as much as the loaded trailer, etc. A battery airplane is too heavy to lift a cargo and fly to another continent. Etc.
Diesel is around 35X as energy dense as batteries on a watts / kg basis.
A gallon of diesel has as much energy as a 200lb battery. So when a semi takes 150 gallons, that would be a 30,000 lb. battery. If the electric motor is twice as efficient, it’s still a 15,000lb battery. A semi pulls 50,000lbs max…
Think of the system now. If every single semi loses 30% of its towing capacity, sure the motors can be more energy efficient but you might need 30% more trucks to do the work. At some point we have 500 horses instead of 1 locomotive. It’s not really a clear advantage.