Why Don't Solar Powered Cars Exist?
Solar power is abundant and readily available, so why don't cars use it?
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With electric cars becoming more popular and a shift towards renewable energy sources is taking place, an obvious question becomes: why don't we simply put solar panels on top of cars? Could this help with the lack of charging infrastructure? Realistically, what would it take for solar powered cars to work out, and why haven't they been successful up until this point?

This video will analyze the surface area of a modern car, providing an estimate for how much solar power it could actually generate, what speeds the cars could be capable of, and how long the cars would take to charge. We'll take into consideration the solar constant, the amount of solar power that actually reaches Earth's surface, the efficiency limits of solar panels, the curvature of the Earth (it isn't flat), and analyze how this impacts a solar car's performance. We'll also check out Aptera Motors, who's planning to make a car that will never need to charge, thanks to solar panels!

Solar Constant - doi.org/10.1029/2010GL045777
Global Consumption - www.eia.gov/todayinenergy/det...
Surface Energy - earthobservatory.nasa.gov/fea...
Solar Efficiency - doi.org/10.1007/BF00901283
Aptera Motors "Never Charge" - www.aptera.us/never-charge

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  • oggyreidmore

    Assuming the Aptera car can do what they claim, it's basically the same as travelling by horse. They travel about 40 miles a day before needing to stop and recharge too. If you're like me and live/work/grocery shop/gym/doctor's office/bar inside a 15 mile radius, this car would be perfect.

  • Skeptical Caveman
    Skeptical Caveman

    Solar would work great for microcars (quandricycles) in sunny countries, since they weigh less, have lower top speed, and are only used for short trips.

  • Pete Lenz
    Pete Lenz

    Ha! Sonos Sion believes it’ll work… (still in preproduction…)

  • Fori Noveli
    Fori Noveli

    where's the variable from the efficiency of the solar panel? or did i miss it

  • Meth FacSarlen
    Meth FacSarlen

    Great video and math! But I hope the next-gen cars will be more toward hydrogen tech instead, the same used by the Sun itself in the end, isn't it?🌞 plus they didn't need lithium or carbon fossil combustion used to electrify the charging points and most houses' nets where e-cars are plugged in. If governments have to choose,let's hope it will be hydrogen. Have a nice sunny day

  • jan imker
    jan imker

    Compute an alternative idea: buying E-car only for commuting + friendly company + friendly gvt.&media. Most traffic is done by commuting. Now, your parking at work could worth 10m2 (i.e. say an average 5m2 to account for a year) for 9h of light each day. This totals ca. 27kW per day. This is more than enough even for today's E-cars to commute 20miles + shopping. The excess (parking is there to stay for many hours more, inclusive weekends) can be given to grid, in exchange for days when not sunny. The air conditioning waste is less too. The batteries less big. Our old cars should be allowed only for longer trips or heavier cargo. Conclusion: we do not need cars covered with panels. We just need smarter behavior, system and decisions.

  • William Gwyn Treharne
    William Gwyn Treharne

    Solar power should be used by cars. Also lorries and trains should use it. Regenerative brakes can also be used by all three.

  • vivien o
    vivien o

    You could get rid of windows and put LCD screens with tiny cameras on the other side. night vision, fog vision, AI augmented vision...

  • Noah Kemkens
    Noah Kemkens

    Hi Toto Wolf :-) Take a look at the Lightyear One please.....

  • Derick Muir
    Derick Muir

    They already have one made!

  • R P
    R P

    What about Aptera.?? It gives you 40 miles of solar charge every sunny day.

  • Thomas Corbett
    Thomas Corbett

    The Aptera can get up to 40 miles of charge a day, I'm going to buy one .

  • Stefan G
    Stefan G

    I think it's feasible if you don't use your car much, like a granny or something. Shopping twice per month and a few errands here and there close by but other than that it's parked outside. Also, assuming it's fully charged when you're out and about, those short trips shouldn't drain your batteries completely, maybe 10-20% and it should be good again in a couple of days.

  • A

    If you do not drive your tesla enough to charge more than 1 time in 2 weeks you would be fine with solar on the car.

  • relicofgold

    If you have a yard stick, 36", and you hold it 10' off the ground in full sun, what is the length of the shadow it casts onto a flat surface? It is NOT 36". This points up a MAJOR flaw in this guy's argument.

  • Alan K
    Alan K


  • psxcancer

    Thanks for putting together this topic. I have a question, what if the electric car was to have a alternator like device (built into each wheels motor to supply the car as well as charge the battery. Like a high, high output one alternator? At that rate the battery could be smaller, making the car lighter as well.

  • Display Name
    Display Name

    What about Aptera? Is Aptera chopped liver?

  • FRM TV
    FRM TV

    24 hours in a day is how you fact check something for solar???

  • Asher

    The 200hr/8.3 days to charge is really 16 days if you consider daylight hours

  • Tonny Obare
    Tonny Obare

    Instead of all the calculations why not get a solar panel of the same size and simply measure its output? 😁

  • Danny Hampton
    Danny Hampton

    Best way to make small light eight cars safe is to make people realize that they don't need there over sized and useless SUV and truck. Most are never off road in the slightest nor do they haul enough cargo, frequently enough, to justify it. When a mini van or wagon would do the same job as an SUV and both are good at towing small trailers for anything that you might need to randomly haul once in a while. Small and med sized trucks also haul more than most need and again trailer if more is actually needed on occasion. And if you don't want to own a trailer or have place to store one then you can rent one cheaply when you actually need one. Also a big SUV or truck is only safer than a small car when there are small cars on the road, but since damn near every body is in a big SUV or truck you are not any safer. I would rather be in a 1 ton car hitting another 1 ton car than a 3 ton truck hitting another 3 ton truck.

  • MegaWilderness

    World Solar Challenge has proved this possible for many years.

  • Gareth Baus
    Gareth Baus

    Honestly the only reason why I won't be reserving an aptera is because I couldn't afford one(or any new car) the fact that their is a non zero chance that a vehicle with such amazing performance can be sold at a reasonable price is absolutely amazing.

  • MR Chief.-__-
    MR Chief.-__-

    But when your working and your car is parked battery would be charged mostly it should be made as Secondary charge source for the car It doesn't have to be perfect we know this clouds etc

  • Nixon Kosgei
    Nixon Kosgei

    All those CGI guys should really watch this video

  • Dummes Stück Scheisse
    Dummes Stück Scheisse

    CDDA players did not like this video

  • Megh Daniel Lama
    Megh Daniel Lama

    Do a collab with donut media

  • Andreas Modin
    Andreas Modin

    And why do we not see more hybrids with 100% electrical drivetrain like the Fisker Karma?

  • Walle Duc
    Walle Duc

    Always park the car under the sun. Do park under the shade like basement and multi-storey car park.

  • mario

    This video will be outdated in less then 10 years. Save this comment

  • Martin Gasparini
    Martin Gasparini

    Why don't just use the solar power on cars to recharge the electric cars... Think about... How many times your car is parked outside doing nothing... When it can use that time to recharge itself

  • Fixing W/ Friends
    Fixing W/ Friends

    So... solar powered boats then?

  • David Hedvall
    David Hedvall

    If you were to use all solar energy on earth, there would be no earth left bruv.

  • TheReefaholic

    I think it is ludicrous to not have solar panels on top of every sold a car. It doesn’t matter that you’re not driving 100% free all the time. It is just at the car can be collecting power all the time during the day. I have three cars. One of them drives less than 5 miles a week I just drive it to the beach. My work car drives 100 miles a day. My family car drives less than 20 miles a week and maybe move twice a week. So two out of my three cars would be worth buying in this case if they had solar panels of any size on the roof.

  • cole2839

    TLDR is because solar panels suck.

  • Andrew Lampart
    Andrew Lampart

    Wouldn't the earth only get half that much energy since the sun is only facing one half of the planet at a time?

  • Michael Eliot
    Michael Eliot

    Now what if you used solar power to heat your hydrogen generator using silicon-iron which then got stored for late ruse in your fuel-cell? That doesn't need much heat or electricity, just time.

  • Billy Norikey
    Billy Norikey

    Theoretically possible if we can make EVs more efficient and if Aptera's specs actually pan out then we will have a solar powered EV.

  • Karin Werner
    Karin Werner

    I want to know if it is possible to charge the battery with wind turbines while driving or when parked in a windy spot?

    • N. Bruce Nelson
      N. Bruce Nelson

      It is certainly possible to charge while parked if you can spare the weight and volume of the wind charger.

  • Jeff Wombold
    Jeff Wombold

    I didn't hear you say anything about the inefficiencies of everything else, and remind people that to charge their electric car fast enough to use, you have to use petroleum, nuclear power or water.

    • N. Bruce Nelson
      N. Bruce Nelson

      Where did this idea come from? It isn't the case

  • SW6

    A solar powered car in the UK is going nowhere. :-)

  • Kenneth Williams
    Kenneth Williams

    If you wanted a solar powered anything, it would have to be on a platform designed to be parked for long periods of time. An RV, a truck trailer. I think all the big rig companies are going the wrong way. A split battery design, with trailers covered in PV and containing a large portion of the battery would be pretty cool.... The way you operated a trucking company would change a little but the implications are cool. An RV with a 500 mile range, solar awning/patio.... Park it for a week and charge. When the battery is full, take off and move to the next spot

  • Kenneth Williams
    Kenneth Williams

    Is this question actually even necessary?

  • Cerolus Elazurin
    Cerolus Elazurin

    Aptera is getting quite close

  • Harley B.
    Harley B.


  • #Crashcource

    I think Hybrid model is more sustainable model? In that we classify Static solar energy and Dynamic solar energy and use combination of these two?

  • Phil Blum
    Phil Blum

    Aptera for the win!

  • Hecx

    Can be done by creating linear strips that can blend with the cars paint. Now thats free energy that corps wont allow to happen.

  • Thomas Corbett
    Thomas Corbett

    I think anyone with common sense intuitively knows this .

  • LaserFalcon

    They say only 20 miles of charging per day

  • Jack Watkins
    Jack Watkins

    But will it run my 600 watt sound system and AC?

  • Lander Stoddard
    Lander Stoddard

    @Engineering Explained Jason, I've been looking forward to you reviewing the Aptera. When they opened the queue, I paid for a place in line. I don't think "solar powered" should be their primary marketing angle, but most efficient vehicle on the road, by a long shot, is pretty awesome.

  • hessu

    I heard about a company named Lightyear starting production of a EV that can be solar charged next spring. Promises up to 70km range from solar per day or 12km per hour, but obviously in the winter, overcast etc. it would be way less. (These numbers seem to be close to the ones in this video btw!) Also seems pretty expensive - that car is supposed to be about $165k. Range would be pretty impressive with 725km (WLTP) on a 60kWh battery, which would mean it's very efficient.

  • George Holt
    George Holt

    well I was with you until you said the earth isn't flat ;)

  • Ciaran Phelan
    Ciaran Phelan

    What about solar powered limousines? Height surface area for the solar panels but low frontal area for efficiency

  • k34561

    I have been doing a back of hand calculation for solar electric car. It is a lot faster calculation. It uses the standard solar panel calculations. These calculation are based on measured data. NREL Horizontal Solar Irradiance map. The solar panel watts ratting. Horizontal Solar Irradiance is really easy it basically states if you lay a 1 Watt solar panel flat on the ground you will get on average N Watt Hours of electricity per day. From NREL map, you can see Boston is 4.0 and LA is 5.5. So in Boston a 1 KW Solar panel X 4.0 gives 4 KWH of electricity. Likewise in LA 5.5 KWH. A standard house solar panel is approximately is a little over 3x5 (39"x65", they vary in size) so approximately 1x2 Meters or 2 M^2. Each panel has name plate of ~300 Watts. I have always though about 4 panels would fit on top of a minivan. That would 8 M^2. 1.2 KW. Let's make 80% efficient. Finally the minivan getting 3 miles per KWH. In Boston: 1.2 KW * 4.0 Irradiance * 0.8 * 3 miles per KWH = 11.5 Miles per day. In LA: 1.2 KW * 5.5 Irradiance * 0.8 * 3 miles per KWH = 15.8 Miles per day. I have always said 10 Miles per day is possible given current tech. That is 3650 Miles per year or 20-25% of the average US driving. There are some solar panels made from nano-particle inks/paints on substrates like mylar. I figure somebody might figure out how to literally paint the solar panes on the car. They would probably only weigh a few KGs and be cheap to install. Labor is one of the biggest costs installing solar panels.

  • Thomas Ngeow
    Thomas Ngeow

    The solar panels on a car will never achieve the efficiency stated. Have you seen cars on the parking lot? How many are spotlessly clean? Any dirt/dust/salt/grime/bug splatter will significantly reduce the efficiency. Any rock chip from the road will damage the panel. You will be lucky to get 25% stated efficiency after a few months on the road.

  • Brendan King
    Brendan King

    I helped build a car for the world solar challenge back in 1990s. Loved the idea of having solar cars. Reality bites!

  • logic1990

    There is also the Sono Motors Sion which is developed in Munich and built in Saabs old factory in Sweden. They promise 30km range charged by the sun in optimal conditions on a day in Munich.

  • Phillip Belcher
    Phillip Belcher

    If you didn’t know the answer to this question before watching, you are likely one of the many ignorant people that believe green energy can power the world. One day maybe but we have a way to go before that can happen. Maybe you should educate your self a little more on energy, before you start demand things from people who actually understand how energy works.

    • mart f
      mart f

      Imagine how cold would the earth become if all cars had solar panels and if all buildings roof had solar panels ... When you convert a suface that is usually warmed by the sun's energy into anything else then heat, you lose that heat. Everything is about balance.

  • Lean Dankr
    Lean Dankr

    What if its electric and solar

    • mart f
      mart f

      Solar to recharge when the car stands still. With lightweight solar panel on top of the vehicule, the autonomy would rise, and the battery could recharge for free while it's not moving. Rather than recharging only when the motor turns into a generator when decelerating.

  • Christian Fensbo
    Christian Fensbo

    The weight issue of car safety you can stop. It has to do with energy - twice the weight twice the energy. Twice the speed quadruple the energy. Also most cars in Denmark are around 2000 pounds or 1000 kg. And the fatalities in the US on the roads are about 11 per 100000 people. The same number in Denmark is 2,8 per 100000 people.


    13:16 sun's only out for about 10 to 11.5 hrs a days not 24... Thanks for the video though... Very enlightening...

  • Ігор Гончаренко
    Ігор Гончаренко

    I remember I saw one prototype on Discovery years ago. It was superlight, not battery, it could reach 70 km/h or so and it was superhot inside.

  • lapamful

    Brilliantly laid out and explained. One of your best videos. But anyway, the other angle is that you could own more than one solar powered car. If it takes 8 days to fully charge (presuming the weather's perfect all the time), and you don't completely use your car's full range commuting every day, then you could own 2 or 3 cars and use one while the others are charging. Of course, you'd better be close to home when your car's low on ray juice, maybe you could leave one car at home and the other at work. But in reality this whole scenario is pretty ridiculous anyway since not every day is perfect and there are things like winter. Best thing to do is just tow a diesel generator everywhere :P

  • Justin Fliss
    Justin Fliss

    Hey! I live in a perfect world you insensitive clod!

  • Scott Nevil
    Scott Nevil

    Would the 173 area be cut in half since the sun is only every hitting half the earth?

  • Inventor Steve
    Inventor Steve

    your math for how long we can drive and at what speed is somewhat wrong. if based on 24hr driving thats unrealistinc. who drives more than 10 hours a day? so new math should be based on that and include how much it would recharge while sitting. great vid tho

  • Steve Bueche
    Steve Bueche

    Aptera is solar powered. $25,900 you get 40 miles a day from just the sun.

    • N. Bruce Nelson
      N. Bruce Nelson

      Strictly speaking, full solar is a $900 option.

  • Colt45caliber

    We're talking in terms of complete dependence on one source of energy. Why not have it as a booster? Even if it can't cover everything it could cover a substantial amount of energy and has the benefit of a free emergency reserve for the poor. You can wait for the sun to charge it. Just have really big batteries and the solar element is always helping store energy but you have to charge for regular use

  • Matt Bosley
    Matt Bosley

    We do have solar powered cars. They're just not powered by solar panels on the car itself. Many electric cars are powered by electricity which comes from solar energy.

  • server1ok

    This is what happens in Scandinavia when the Gov. starts taxing a worker

  • Janne Peltonen
    Janne Peltonen

    Thanks for an interesting video! I saw an announcement on that car somewhere, maybe that British electric vehicle show... One thing though, taking a planet-wide average hardly makes much sense when talking about solar irradiance, that's why there's actual tables out there for solar power installation engineers (and DIYers) that give the actual numbers for multiple locations on Earth. In a theoretical video like this, I think it might've been a good approach to give the energy received at a few different latitudes and see how these cars would work there. After all, a daily driver would be spending most of its service life not traversing that many latitudes...

  • McDaniel77

    The Sion from Sono Motors will be a solar powered EV.

  • Martial Bachoffner
    Martial Bachoffner

    Let's do the opposite. What would be needed to power, let's say your Tesla, with solar energy. Or at least charge to battery while you drive or while the car is parked?

  • $hamik_RoY

    And if you stay near the poles. Then you need 6 months to charge your car again.

  • Ben Ponsford
    Ben Ponsford

    An interesting point you touched on about vehicle weight. I prefer lighter cars for many reasons, but from the safety point of view I'd like my vehicle to be as light as possible so I'm inflicting the least amount of damage to whatever I might hit. As opposed to the selfish approach of having something big and heavy to protect yourself, causing a vicious circle of everyone else getting big vehicles so they're not the loser in a collision. Now we have an SUV craze in UK cities, burning up more fuel and making the place more dangerous for everyone, especially pedestrians and cyclists. On a lighter note, another technically fascinating video, thanks.

  • Chris Griffiths
    Chris Griffiths

    Good Presentation.

  • Rick K
    Rick K

    If you have a short commute, which some of us do, and use less than 10% of your battery a day in a Tesla, that would theoretically compute quite well... And even if it doesn't get me all energy for free, it might still hit 80% of my needs. There is one major drawback though: I usually don't park outside, especially at work. So the actual sun time my car gets might be as low as 5 hours a day, which makes this unfeasible. But I do agree with Anton, it would be nice to have that option.

  • Commenter

    That 33% number for efficiency is also extremely optimistic. Efficiency is measured at 25 Degrees C. Which never happens in the real world. The Sun heats them up. Efficiency drops off considerably after being in full sunlight for even a short time. This sadly effects the most efficient panels more than some of the less efficient thin film technologies. You'd be lucky to get 20% in an application like this. Less if you wanted to use reasonably priced panels. And there are losses in Area efficiency related to the cells themselves. You can't use one big cell inside the panel, the voltage will be much too low. You'd need link smaller ones in series. There is a reason the Toyota Prius Solar Panel roof wasn't even part of the charging system. Solar Racers make it work by increasing surface Area, and minimizing weight, and has extremely low drag. Basically like a wing. No production vehicle is in this sort of ballpark.

  • Mervyn Morris
    Mervyn Morris

    Wouldn't solar panels be useful to extend range? And Wouldn't it be even more useful on buses or trucks. A Tesla is powerful enough to propel it to 100 kph in3 seconds then surely the same running gear could propel a 50 seat bus with at least three times the roof area with no windows to worry about?

  • Frank Huber
    Frank Huber

    Batteries, solar panels, pffft! I'm waiting for those fancy newfangled super capacitors we been hearing about for a while now, then I'm gonna reconfigure my tailpipe as a lightning rod.

  • FoxVoxDK Noneofyourbusiness
    FoxVoxDK Noneofyourbusiness

    Ehh, one word: Aptera. xD Yes yes, technically it's not powered by the sun directly, but at least you're using power to some extent stored from charging in the sun. xD

    • Why Not
      Why Not

      I’m a reservation holder. At the same time, 100 miles per kWh is an aspirational mountain to climb. I currently have my reservation for a 400 mile version with full solar. If the Beta tests show 100mi/kWh, then I might switch to a 250 mile battery version. I might anyway because I don’t think this will be my road trip vehicle but perfect for getting me to work and running around every day. Even if it doesn’t keep the battery charged- who wouldn’t want a vehicle that can keep the AC running while it sits so that when you come back after being in the store for an hour- it’s still nice and cool inside!!

  • Mark Parent
    Mark Parent

    Just put a solar array on your home if you had the space for one.

  • Jim Kennedy
    Jim Kennedy

    THanks for shedding light on this....

  • Jismal Jamal
    Jismal Jamal

    Is the area for the hemisphere is 2pir*r^2. Just curious why used circle approximation of pir*r^2

  • turbine graphics 16
    turbine graphics 16

    Why is the sun just called the sun, it would be like if Earth was just called "the planet".

  • David Alexander
    David Alexander

    Nontheless,every little helps surely... if we recapture energy from the brakes etc,it must be worth having a little bit coming in from the roof.

  • Peter is Googling
    Peter is Googling

    engineering explained!

  • Mister Melancholy
    Mister Melancholy

    We do have solar powered cars... Look at FIbill...

  • Kara Sene
    Kara Sene

    Maybe a wild idea, but I was thinking. Would a solar panel at least be enough power to run the ac/heat and maybe the radio so most of the battery goes towards actually propelling you down the road?

  • actionjksn

    I like the idea of solar panels on the vehicle to supplement the charging I don't think it's practical as a replacement for plugging in though.

    • N. Bruce Nelson
      N. Bruce Nelson

      For some, It won't be. Others will be able to meet their entire energy needs through the full solar option.

  • Natan Salazar
    Natan Salazar

    even if solar energy is not enough for the car to get around without external charging, it can be enough to make a car travel a greater distance without using larger batteries or more efficient motors

  • You Tube
    You Tube

    The simple answer is : Current technology doesn't work with the surface area available on cars & until solar panel & battery size & efficiency improves enough that will remain the case.

  • Badger M3
    Badger M3

    What about covering a regular Tesla with solar panels and seeing how much the range is increased.

    • N. Bruce Nelson
      N. Bruce Nelson

      The most efficient Teslas have more than 2.5 times the energy requirements for the same speed.

  • Michael M
    Michael M

    Really interesting video . . . but you imagined that the reality math would've produced a longer charging period for your solar powered car, and it probably would have if you didn't pull the 250 W flat earth value into the equation. I suspect the more realistic 125W from the exposed side of the globe earth would've delivered the longer result you were expecting. Now, I'm going to go watch some more of your videos . . .

  • Christian Meeks
    Christian Meeks

    Sounds like an excellent commuter car for people that drive less than half an hour to work.

    • CaedenV

      yeah... would work for me I bet! Round trip to work and back is ~20 miles, with the occasional trip to the grocery store mixed in for an additional 5 mi. This would work great! Problem is that it is going to be expensive... and when you drive as little as I do, then you get a bit more price sensitive. I use my computer several hours a day, and it lasts me a very long time, so I will spend almost any dollar amount on a computer and it is justified. But I only drive a short distance every day, and only ~30-40 min if I time the traffic right. So paying the $8-10k for a cheap but reliable used car becomes difficult to justify... much less something with the up-front cost of this kind of solar car. The price increase would probably be more than the fuel I put in my current little car. I wonder how much cheaper it would be to have the same car, normal body, and pay to install a solar car port in my driveway. Putting the solar on top of the car just seems to over complicate things.

  • Forrest McMahon
    Forrest McMahon

    I’m hearing yacht companies claiming solar powered electric yachts with unlimited range. Doesn’t seam possible to me. I would love to see a video on the subject.

    • Mark Parent
      Mark Parent

      Boats seem the perfect place for solar ...you could tow along a whole array of solar or have some sort of fold out array.

  • Michael Chownyk
    Michael Chownyk

    Real world math? I have a Mitsubishi Imiev that does get 100 Watt hours per mile. I recharge my car with 100% off grid solar power from my backyard. I have 9700 Watts i’ve rated capacity and 8500 W of inverter. During low light levels I use a level one charger(800watts) during brighter more full sunlight conditions are use a 3.1 kW level to charger. It feels real good knowing where my power came from is a clean source.