If half of American commuters switched to EVs, the daily energy demand on the grid would only increase by 10-15%. The difference between peak load and average load is close to 30%, so we could handle that new EV load with the existing generation capacity. We just need market solutions to incentivize owners to charge during off peak hours, which most utilities already have via time-of-use rates and EV-specific plans.
To be more clear: the US grid with its existing generation capacity could certainly handle 41% of consumers switching to EVs. We would simply not ramp down as many power plants at night as we do now [1].
However, that would result in this additional marginal demand being satisfied mostly by fossil fuel plants: natural gas and coal, which currently ramp up and down on a daily basis. What is more likely to occur is that the new marginal demand caused by EVs will be satisfied by new capacity from solar and wind farms. Areas with good solar capacity (CA, FL, the southwest) will incentivize EVs to charge during the day, and areas with more consistent wind capacity (the midwest) will incentivize charging at night. Coal plants will increasingly close for economic reasons, while existing natural gas plants will continue to run at lower capacity factors.
Depending on how electricity and carbon markets are structured, and how the costs of different generation technologies and fuels change in the future, there's a good chance that the US grid of the future will look like how I described, and that people will pay less of their income on energy services, and that the air in cities and homes will be cleaner, and that people around the world will be less at risk from the effects of climate change.
You're right. There are two major errors in just this one paragraph from the article:
"Worldwide, humans use roughly one zettajoule per year. Satisfying that demand without further contributing to climate change means we’ll have to drastically speed up deployment of zero-carbon energy sources. Providing 1 ZJ per year with only solar PV, for example, would require covering roughly 1.6 percent of the world’s land area with panels."
Actually, humans used 162,494 TWh of primary energy in 2017, which is 585 petajoules (PJ). The authors admit to rounding up from roughly 600 PJ to 1000 PJ "for simplicity" later in the article. Rounding up by 66% is hardly appropriate for a back-of-napkin calculation, much less in a published article on a very serious topic.
Then, the authors imply that replacing all primary energy with solar power would require the same amount of primary energy. This is not true. If we were able to electrify all of humanities energy needs, we would only need 1/3 as much primary energy as we use today, since today's primary energy is mainly served by extremely inefficient fossil fuel combustion (coal and gas in power plants, petroleum for transport). 600 PJ is a reasonable estimate for primary energy use in 2021, so we would only need to build 200 PJ of solar power to replace fossil fuel combustion. The article called for 1000 PJ of solar, while reality is closer to 200 PJ. They were off by a factor of 5!
Obviously, this paragraph was an over-simplification and was meant as a thought experiment. But the sloppy rounding error and the lack of acknowledgment of the primary energy differences between solar power and fossil fuel combustion call into question how deeply the authors really understand the problem of climate change, and the solutions we have available.
This IEEE article makes some questionable extrapolations in my opinion. First, they start with 2017's global primary energy consumption of 600 PJ, and then round it up (by 66%!) to 1000 PJ ("for simplicity"). Then, 1000 PJ is used as the baseline that we would need to replace with zero carbon sources, leading to scary-sounding propositions like "covering roughly 1.6 percent of the world’s land area with (solar) panels".
But that's misleading. Up to two thirds of the primary energy we "consume" each year is wasted: it is used to pump, refine, distribute, combust, or otherwise perform work and/or create heat that is not directly needed or wanted for the desired "energy service", e.g. moving a vehicle or lighting a home. Electricity generated from fossil fuel combustion has an immediate primary energy loss of 40-70% due to the inefficiency of heat engines. Wind and solar power plants do not. For example, if a solar plant produces 1GWh of electricity in a day, the full 1GWh is considered "primary energy production", while a natural gas plant that produced 1GWh of electricity in a day may have consumed 2-3GWh of natural gas "primary energy" in order to do so.
Similarly, electric vehicles are much more efficient than combustion engine vehicles at converting "intermediate energy" into useful work (a charged battery or refined gasoline into motion). Heat pumps are often more efficient at heating spaces and water than burning gas.
So, if we are able to generate most of our electricity from renewable sources, and electrify all ground transport, space/water heating, and many industrial processes, our primary energy use will be significantly lower in the future than it is today! That's not to say there aren't major technical and political challenges ahead to mitigating climate change, but oversimplifications that make the problem seem harder to overcome are of limited usefulness.
A 600 mile battery - say 1-1.2MWh - should only weigh around 10-12K lbs (at 260-300 wh/kg). And you can throw out the 5K lb carbon capture device, and 5K lbs of engine, transmission, exhaust, cooling and fuel system. Add back 500 lbs of electric motors. The payload difference is actually not that significant, certainly not 33% more payload for the diesel+CCS. Such a big battery would be expensive though. I expect most EV semis will have 300 - 500 miles of range. This system sounds good for decarbonizing the diesels that are already on the road though!
you can throw away the 5k of engine and drivetrain components, and then throw in 6k in electric motors, transaxles/transmissions and added copper wiring
From the vehicles I have actually built and weighed there is a much larger increase in weight than you are predicting.
You can see that 1/3 the range for the same weight, and this only gets worse as the vehicle gets heavier. For class 8 trucks wind drag is a very small percentage of the losses, rolling resistance from weight is the largest loses. So I don't think linear distance scaling you assume adds up.
Its going to be an interesting transition and we know that electric trucks will be great for some use cases but its going to take a mix of solutions, especially in countries where their grid infrastructure is no where near as robust as ours.
You've compared the range of a Model 3 driven at 75MPH to a Camry driven at 48MPH, for one thing. But I don't know why you would bring passenger cars into the discussion, since you can't scale performance linearly from cars to class 8 trucks. You've already made that mistake by scaling cabin heating requirements linearly with battery capacity, for example.
> For class 8 trucks wind drag is a very small percentage of the losses, rolling resistance from weight is the largest loses.
According to this source[1], for class 8 trucks at max gross weight on level road, aero and rolling resistance losses are the same around 50MPH, and aero dominates after that. Is that source wrong, or out of date? Source says "aerodynamic drag and tire rolling resistance are major contributors to energy loss" - neither is a "very small percentage".
From everything I've read publicly, EV semis won't have transmissions or transaxles, just motors on the drive shafts (4x120lbs). Not sure where you get 6k lbs, even including the "added copper wiring".
I can totally see a 1-2 ton payload advantage for diesel+CCS over EV semis when the required range is 500+ miles, just not a 15k lbs advantage. Ultimately the market will decide what tech to use for different routes though, and I agree that a variety of solutions will be utilized.
An aux heating system would not be necessary for an EV semi: most of the cited 40% of range lost suffered by passenger EVs is due to cabin heating, but an EV semi would actually produce enough waste heat in its powertrain to comfortably heat the cabin[1] (just like a diesel semi!).
There are also some range and power losses due to increased internal cell resistance when the battery is cold, but the effects of this diminish as the battery warms up with use. Actual range loss for an EV semi in the cold should be minor, probably similar to the range loss for ICE semis in the winter.
> we believe electrification won't work for long-haul trucking. Bill Gates agrees.
is very different from
> we ... think electrification is going to be trickier for long-haul trucking than for cars
Electrification will be trickier for long-haul trucking than for cars; no one would disagree with that. That doesn't imply that electrification "won't work" for long haul trucking (a statement that many would disagree with).
I hope your system does work, and that it's cost effective! It will allow us to start decarbonizing earlier! But medium to long-term, it's pretty clear (to me at least) that all forms of ground transportation will be battery/electric powered.
Totally. We'd genuinely love to be wrong - electrification is a great solution where it works! But our team has built battery electric and hydrogen fuel cell class 8 trucks, and our experience suggests they’re decades away from competing for long haul transport (given range, charging time, payload capacity, etc.). Even if that day comes, our solution is a fraction of the cost, works today with existing fleets, and with biofuels, it can make a truck carbon negative! That's something electrification wouldn't be able to achieve even if we did manage to overhaul the world's grid so that it's completely renewable, which we think will take decades, especially in the developing world.
> At 20 degrees, the average driving range fell by 12 percent when the car’s cabin heater was not used. When the heater was turned on, the range dropped by 41 percent, AAA said.
So the majority of the range loss in cold weather in passenger EVs was due to heating the cabin. Do you think an electric semi would also require 30% of its battery capacity be dedicated for cabin heating in cold weather?
Assuming 2KWh / mile average consumption[1], an EV semi powertrain would be pulling ~120KW continuously from the battery. Even at 90-95% efficiency, there will be 6-12KW of waste heat available in the powertrain, more than enough to heat the cabin in cold weather. Modern EVs actually do scavenge waste heat from the battery and motors for cabin heating[2], unlike the EVs tested in the cited article.
But even without using the available waste heat, a 6KW resistive cabin heater would only use 18KWh over a 3 hour drive. For a cheap passenger EV, this could be 20-40% of the battery, but for a semi with 500 miles of range, 18KWh would only be 1-3% of the battery.
Put more succinctly, the battery in an EV semi would be 5-10x larger than the battery in a passenger EV, but the energy required to heat the cabin will be roughly the same. So the effect of cabin heating on range loss would be 5-10x less on a EV semi than a passenger EV.
I would remove this line from your post: "plus the batteries lose > 40% of their range in cold weather" because I don't think that claim is supported by any source, or by basic logic and math, in the context of a semi truck.
I hope you are right, because that's better for the environment. Independent testing of the Tesla Semi will prove or disprove all these claims. Regardless, the huge point here is that we offer a retrofit solution that solves carbon emissions from trucking now.
> Independent testing of the Tesla Semi will prove or disprove all these claims.
It sounds like you think it is fine to make claims that are unsupported by any evidence, or by basic logic, until a counter-example to your claims is physically available for independent testing. That’s unbelievably disappointing to hear.
"Our device works perfectly in all climates, while electric vehicles lose more than 40% of their range in cold weather, making them impractical for many parts of the world.”
Having this tagline on your website is ignorant if you hadn’t done the math, and intellectually dishonest now that you have.
I agree that the “huge point” of this announcement is the device you’ve created. You just don’t need to resort to misinformation to promote your product.
