Engineering Professor Answers Electric Car Questions

WIRED

Professor Willett Kempton joins WIRED to answer the internet's most interesting questions about electric cars. Has Elon Musk's high profile public persona affected Tesla sales? Will electric cars ever charge as quickly as pumping gas for a traditional combustion engine? Why can't Americans by Chinese EVs? Answers to these questions and more await on Electric Car Support.  Director: Justin Wolfson  Director of Photography: Charlie Jordan Editor: Richard Trammell Expert: Willett Kempton Line Producer: Jamie Rasmussen Associate Producer: Brandon White  Production Manager: Peter Brunette Production Coordinator: Rhyan Lark Supervising Casting Producer: Thomas Giglio Camera Operator: Caleb Weiss  Sound Mixer: Brett Van Deusen Post Production Supervisor: Christian Olguin Supervising Editor: Eduardo Araujo Assistant Editor: Billy Ward

Transcript

00:00I'm Willett Kempton, Professor of Electrical and Computer Engineering at the University

00:03of Delaware.

00:04I'm here today to answer your questions from the internet.

00:07This is Electric Vehicle Support.

00:10RHAB members asks, EV explained, how do electric cars actually work?

00:19I'm going to use this diagram to explain.

00:21A gasoline car uses a fuel pump and gasoline pushed in.

00:24Instead, for an EV, that blue cable that you see is a charging cable.

00:28You plug the car in, and electricity flows into the battery.

00:33So instead of a fuel tank, you've got a battery.

00:35That big yellow thing is a really large battery.

00:38It's more or less the same as a battery in your cell phone or laptop computer.

00:42It's maybe using lithium ion.

00:43That's a traditional type, and you can store kilowatt hours of electricity.

00:48Then, when you drive, you unplug, of course, and now the electric energy, the kilowatt

00:52hours that's in that battery, is flowing out through a motor drive, the blue thing in the

00:58diagram.

00:59So that's turning the battery power into electric energy that's ready to run a motor.

01:05Pretty Repair 954 asks, why do electric cars accelerate faster than most gas-powered cars,

01:12even though they have less horsepower?

01:14Average electric car might have less horsepower than a gasoline car.

01:18It'll still accelerate much faster.

01:20The torque of an electric motor is 100% from starting all the way to full speed.

01:26Torque is the turning power.

01:27If you're turning a crank and pushing harder, that's more torque.

01:30If you're pedaling a bicycle uphill, you have to push harder on the pedals, that's more torque.

01:35On a gasoline motor, you get maximum torque only when you're at almost the maximum RPM.

01:41So that's why you have gear shifts in all this.

01:43The way you run in a gasoline car, it's .

01:48You're shifting and moving to higher and higher gears.

01:51That's because you're only getting maximum torque at nearly the full RPM.

01:55So you don't have any of that nonsense with an electric motor.

01:57So randomnerd827 asks, how environmentally friendly are electric cars actually?

02:04You consider two things in environmental friendliness.

02:07What are the mining, materials, manufacturing, all that that goes into making the car?

02:12And then what about the fuel consumption and pollution from fuel consumption?

02:16If you use electricity, there are probably some emissions in creating that electricity.

02:21When you drive your new electric car off the lot, it's less environmentally friendly than

02:26a gasoline car that you would have bought new and driven off the lot.

02:29There's more materials, more weight, and some of those materials have environmental impacts.

02:34So actually, the embodied environmental cost of the car is a bit higher, not a huge amount,

02:40but maybe 30% higher, something like that.

02:42If you are using gasoline or diesel, obviously, you've got emissions right out of the vehicle.

02:47That is so much dirtier that over the time of driving the car, and maybe as soon as two

02:51years after you've bought it, you're already ahead.

02:54And over the life of a car, typical car in the US lasts 12 years or so, you're much more

03:00environmentally friendly.

03:01Okay, morecowbell520 asks, will we see 600-mile range EVs standard in the next 10 years?

03:10We have an announcement from Toyota that they will have a 900-mile Toyota in 2027.

03:17That's, what, two years, not 10 years.

03:19But you said standard.

03:21Do we want a 600-mile standard for EVs?

03:23I would say no on that.

03:25Maybe you need 600 miles or 900 miles or 1,500 is certainly possible with matters that we

03:31see now coming.

03:33But do you really want that?

03:34Because that's going to be more weight.

03:35For most people, 300 miles is really a reasonable range.

03:40And that's what most EVs sold in the US are today.

03:43You can buy a 500-mile range EV in the US today.

03:46It's going to cost you maybe 80 grand or 100 grand.

03:49Or would you rather have a lighter car, probably get a little bit better mileage, pay less for

03:54the car, and get, say, 300, 350 miles range?

03:58That cool guy.

03:59What is maintenance like on an EV?

04:01EV maintenance is way less than maintenance of a gasoline car.

04:05Mostly it's going to the dealer and they check some things and do software updates and it's

04:10all free.

04:11The electric systems on the EVs are generally warranted for 100,000 miles.

04:15So very little maintenance.

04:16You got to still fill the windshield wiper fluid, check the brakes, and of course there's

04:21no oil changes or any of that.

04:22You still have to lubricate the chassis.

04:24So very little maintenance.

04:26Bean Tiger asks, China makes cheap electric vehicles.

04:30Why can't American shoppers buy them?

04:32The purpose is to protect the American automotive industry.

04:35If those were let in at very little tariff, it would be very hard for the US automotive industry

04:40to develop EVs, which is what they're very furiously trying to do now.

04:45The Chinese have, as a national policy, have emphasized new technologies, not sort of

04:51supporting legacy technologies.

04:53So they are the world's global lead in solar panel manufacturing.

04:59They are making more wind turbines than I think all the rest of the countries of the world

05:03combined.

05:04And they've moved way ahead on electric vehicles, way ahead of any other company with legacy

05:09automotive industries like Germany, Japan, Korea, the United States, obviously.

05:14They have emphasized, in the case of electric vehicles, learning how to make them and having

05:19a bunch of companies competing with each other to make very high quality, very good, well-engineered

05:24electric vehicles.

05:25Morgan Zella asks, does carbon footprint of EVs include lithium mining?

05:30Yes, has to.

05:31Any decent, peer-reviewable study of lifetime carbon emissions or pollution has to include

05:38all the mining, materials processing, manufacturing, everything.

05:42When you drive the car off the lot, EV has a larger carbon footprint than a gasoline vehicle.

05:46Within a year or two of driving, it has less and it gets much less over the lifetime.

05:51Bull Z from asks, why are hydrogen cars not more prevalent than EVs?

05:56Just from an energy standpoint or an efficiency standpoint, hydrogen cars, you start with electricity,

06:02maybe get natural gas, but ultimately you're going to have electricity making hydrogen.

06:06So you lose half the electricity when you turn it into hydrogen, and then you've got the

06:09energy of the hydrogen that goes into the car instead of plugging in electricity straight

06:14into the car.

06:14The car has a tank, well that's cheaper than a big battery, great, but now when you take

06:19that hydrogen and turn it into electricity to drive the motors, you're losing another

06:24half.

06:25When you take electricity and put it straight into the car's battery, you're losing maybe

06:3610%, 20%.

06:38So hydrogen, you're using almost four times as much electricity to drive the car.

06:44Electricalhyena5164 asks, do EV batteries really outlast the car?

06:50Yes.

06:51So they're warrantied for 100,000 miles, but what does that mean?

06:54That means they have at least 80% of the range still in the car.

06:59100,000 miles after you buy it, if I had a car that had 200 miles in the beginning, I'd

07:04now have a car that has 160 miles.

07:06It still drives great, everything's the same, I just can't go quite as far.

07:10Jen Expat asks, what is the lowest tech electric car?

07:15The lowest tech electric car is maybe the Fiat 500e, which has got a 150-mile range battery.

07:21It's a really small car, it doesn't have any frills, really low cost, you can buy it used,

07:25you know, maybe 8,000 bucks or something.

07:27Nothing wrong with it.

07:28ExmoorCowBellsX asks, have Elon's antics affected Tesla sales in the real world?

07:34Yeah, you can see there's a reduction in sales that correspond to his high public visibility

07:40and what actions he was taking.

07:41I don't remember the percentage, but there's an effect and there's an effect across countries.

07:45So I think it's actually reduced their sales rather than just leveled them out.

07:49And that gives other US automakers and worldwide other automakers a chance to sell more vehicles.

07:54TechnoGeekyGuy asks, do you still call it the gas pedal or what?

07:59You call it the accelerator pedal.

08:01AlgebraicIceKing asks, why is fast charging only DC?

08:05Why can't we fast charge with AC?

08:07My team at the University of Delaware has developed a way to do that in the US.

08:11So it used to be that AC charging in the US was limited to just 19 kilowatts.

08:17That's how fast the power goes into the car.

08:20Just for comparison, a toaster is about one kilowatt.

08:23It's faster than a toaster, but it's only 19 kilowatts.

08:25So if you've got a large tank, it might take you 12 hours or more to fill it up.

08:30So we've developed a 100 kilowatt AC charger, which is a much lower cost way to quickly

08:36fill up a car.

08:37So when you're charging with AC, use a plug like this in the US now.

08:41If you have a Tesla, it's a little bit different shape.

08:43There'll be some other cars that are starting to use that too.

08:45But this is a very common AC charging connector.

08:48You plug it into the car and it starts charging.

08:52The other end of this wire is a plug.

08:54So you just plug it into an outlet in your garage or wherever is convenient on the porch.

08:59You know, I've gotten an expert at finding plugs outside of Airbnbs and places.

09:04Plug that in, pull the cable over to the car, plug it in.

09:08That's an AC charging system.

09:10It's cheap.

09:11You can buy something like this for $300 or something.

09:15DC charger is a Coke machine size thing.

09:18It's maybe 20 grand up to a hundred grand and you put it in with a forklift.

09:22You would never have that at home.

09:24Home charging is always AC.

09:26Fast in route charging is usually DC.

09:29That done 776-08-645, when will we have solar panel back windows for electric cars?

09:36You could run a car off solar, but you need much more area than the whole car.

09:40You would need solar on the hood.

09:43You need it on the trunk in the back.

09:45You need it on the roof.

09:46You need it on the side.

09:47And to even run for like a normal day's driving, you'd need to leave it outside about three

09:53days.

09:54Schweitzerend asks, question for EV experts.

09:58Is that the actual noise the motor makes or do they add that so they don't silently run

10:02over everyone?

10:03Yeah, that whirr that you hear when you hear an electric car combine, that's the actual

10:07noise that it makes.

10:08Nick Vanestal asks, anyone got a quick source on how many consumer EV models already support

10:15vehicle to grid or even just vehicle to home?

10:18Vehicle to grid means providing power out of your battery to the power grid.

10:23Now, why would you want to do that?

10:24That has value because it means less strain on electric lines and it means generators,

10:30if they're stressed to the max, they don't have to go further.

10:34They can turn down maybe.

10:35Vehicle to home is using your car to power your house when the power goes out.

10:40Both of those are becoming much more something you'll see.

10:44A Quora user asks, how close are we to getting cheap solid state batteries to power electric

10:49cars?

10:50Solid state batteries aren't lower weight and mass, so that's an important advance.

10:55And so there are today cars in China being sold with solid state batteries, but there are

11:01none sold in the U.S.

11:02There's a plan to have them sold to U.S. customers in 2027.

11:08So we're very close to that.

11:10Lanavita12 asks, why do EV and EVike batteries keep catching on fire?

11:15They're using lithium ion batteries.

11:17Lithium is flammable and burns at a very high temperature, which makes it hard to put out.

11:23Sometimes if they're not properly managed, but that shouldn't ever happen, it means that

11:27two or three systems have all failed.

11:30Energy can cause fires and heat and all kinds of other stuff.

11:34So we have lots of fires with gasoline cars also.

11:37In fact, even though EVs are a new technology, the number of fires per 100,000 miles driven

11:43in gasoline cars is already much more than the number of fires in EVs.

11:49So it's just that EVs are novel and so, oh, EVs caught on fire, so that's news.

11:54DevZeroOr asks, will charging electric cars ever be as fast as pumping gas?

12:00Probably not.

12:01It's just harder to move the amount of energy needed than to move a liquid fuel.

12:06And yeah, maybe you can get the car to accept a really fast charge.

12:09Like megawatt charging is a thing.

12:11There's a new standard for megawatt charging, but then you're going to have a really high

12:15electric bill because when you use a lot of electricity at the same time, they start charging

12:20you more money for it.

12:21Awkwardplenty24 asks, is wireless EV charging the future or just a cool gimmick?

12:28It's just a cool gimmick.

12:29It's really easy to plug in.

12:30It's not necessarily something you have to solve.

12:34You have to have the car positioned exactly over the coils that are in the pavement or

12:39the garage or whatever.

12:41One of the car manufacturers I visited, they said, a person can't park precisely enough

12:46to do this.

12:47We have to have automated parking by the car to get it positioned exactly where we get

12:52enough transfer.

12:53And you are losing energy.

12:55It's not going to be 100% efficient.

12:57Wire-to-wire is always going to get more across.

13:00Contact Trains asks, what actually happens to EV car batteries after they die?

13:05When an electric car is done, you scrap the chassis, the metal, like you would in any other

13:10car, but then the lithium-ion batteries are handled separately.

13:13Over time, I think what we'll primarily see is that the batteries are disassembled because

13:17we want to reuse that lithium in other batteries in the future.

13:21So there's a disassembly of the batteries and separation of the materials, and then they

13:25get used in other products, for example, other lithium batteries.

13:29A Reddit user asks, by the end of the 2030s, will electric cars have largely replaced gas-powered

13:34cars in the United States?

13:35End of the 2030s, that's like 2038, 2039.

13:39In terms of new car sales, personal opinion, yeah, I mean, there's going to be very few

13:44gasoline car sales by that time.

13:46It's a superior technology.

13:47You know, once you've driven an electric car, you say, oh man, I'd upgrade another gas

13:52car.

13:53Only people in specialized situations, they need to drive a long ways or there's some reason

13:57they need to refuel quickly.

13:58They may keep buying gas cars for a while, but by the mid-2030s, early 2030s, you say,

14:04oh, well, I'll just buy a 1,000-mile range EV, you know, because I don't want to go back

14:08to gasoline.

14:09Colby Ambassador 4891 asks, are EV sales really tanking, considering buying one this year,

14:15but hearing mixed things?

14:17EV sales are going to level out a bit with the tax credit going for the next several years,

14:22but EV sales are not tanking, the rate of growth has dropped a bit.

14:26We're at about 10% of new car sales are EVs.

14:29I don't really expect that to shrink.

14:31Mark J. Parker Sr. asks, can we retrofit EVs so these tiny forever batteries will continuously

14:37run an alternator to continuously charge the car's EV battery?

14:41Then you'll never have to pull into a gas station.

14:44OK, well, this is a perpetual motion machine.

14:47No, you can't make something that works like that.

14:49Patoshi asks, why aren't gas stations installing EV chargers?

14:53More customers, more revenue, minimal upfront investment.

14:56That's a good question.

14:58Some gas stations are installing EV chargers.

15:00Sometimes people use them, and not only that's fine, but a gas station's not really a place

15:04you want to hang around for half an hour.

15:07If you're going to be out there a half hour, wouldn't you rather be at a 7-Eleven or McDonald's,

15:12you know, someplace where you could have a coffee, maybe a little food?

15:16Or would you rather be someplace that's really smelly and kind of dirty and grease on the

15:20pavement?

15:21No, gas station's not a good place for EV charging.

15:25You're much more likely to have a fast food place or some kind of small shop where you

15:29can buy a bite to eat, something like that.

15:31That's a much better place for an EV charger.

15:34OK, that's it.

15:36That's all the questions.

15:37Hope you learned some things for next time.

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