Why Don't Solar Powered Cars Exist?

Solar power is abundant and readily available, so why don't cars use it?

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!

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[Ilander]

This is the ONLY YouTube show I watch where I get giddy on seeing a whiteboard filled with maths at the beginning.

[MichaelSmith-ziqm]

I've been in the solar industry for 8 years, and am very familiar with watts per meter squared and the available amount of energy from the sun. This EE video is spot on, and very accurate! Thanks for doing all the math that we're too lazy to do ourselves! Keep up the good work!

[aaron]

As my 2-year-old boy starts screaming and running around:

"So, we need to understand the son. and the son has all of this energy..."

[Thoughtful_Balance]

Really hoping for Aptera's success. The car may not appeal to everyone and fit everyone's needs but innovation and pushing boundaries is always a good thing.

[garethbaus]

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.

[stauffap]

I have to give you a like just for the math, since that's exactly what you need to do when you're talking about energy, energy storage etc. It seems like it's so neglected in the public discourse. People just claim stuff without backing it up with numbers and actual physics.

[anzonix]

Even if it is slow, I'd still like to have solar charging as a feature.

[Tore_Lund]

They do exist! The point is driving a car optimised for energy efficiency, and a not extreme driving mix: My car 1800lb 20kWh EV. Small, but uses only 160Wh/mi on average. On the roof I have a measly 100W solar panel connected to a DC boost converter making 300V DC. It is always connected to the battery and charges it with 300 mA whenever the sun is up. This gives me 3-4 miles per day in range. This is not much, but it is enough for errands around town 3-4 times a week. I only drive 3000 mi yearly, so this supplies more than half my charging needs! Going to put another 100W panel on the hood some day to unplug completely. except for when visiting family.. If you need to drive 40 mi daily on the HW, this won't work!

[CaptainRotmeat]

One thing that I think bears mentioning is that even if you can't drive 100% on solar, that passive charging can still be useful.

Instead of having to go to a fast charger every week, maybe you're going once every 2 weeks, or every 2 months, etc.

That's a huge help to people who can't charge at home.

[sadlogic]

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.

[RDMracer]

In the Netherlands, this video feels like someone explaining why you cannot build below sea level...

[dva]

When I was younger, everybody kept telling me AC lowers your mpg so we would just roll down the windows instead. But with the windows down, it creates drag..? So what is the best option after all? AC or the windows?

[fabianfeilcke]

Putting solar on cars does not make much sense. They rarely are in a good position to get sunlight and the panels are expensive to integrate. Its much more cost effective to put a couple of panels on top of the parking lot where the car is usually parked during the day. Keeps the car cool and charged.

[RyanWilliams]

Thank you for mentioning the Aptera! I was thinking about it during the first 2/3 of the video, and then I was like, “Oh, hey! There it is on the whiteboard!”

[LazerLord]

Me, contemplating building a solar-powered van camper... These equations will be useful...

My plan is to have a deploy-able array to use when I sit at a campsite for a few days. Should be a decent size and enough to at least maintain climate control and cooking.
Looking at that 8.3 day figure to charge actually makes me think this is viable. The van with deployable array would have at least 3x the solar area, so only ~3 days to full charge? That's a normal weekend camping trip!

[JCMik]

I was intrigued by Aptera before, but going through all the math has got me convinced- it's a perfect fit for my needs, and I hope to see more like it soon!

[redflash]

2 vids in a row with lots of whiteboard. Oh yea its all coming together.

[kengineer_au]

I was involved in my University's World Solar Challenge team. The calculations on the surface level radiation are a bit off. Even as far from the equator as Melbourne, Australia we regularly get over 1000 W/m^2 days. Places like England you'll get less but you can look up IRL solar radiation and see for yourself. Real world high performance solar cells like they use in the World solar challenge get over 300W/m^2 actual output.
Edit: Also if you do the math with even just cheaper regular panels then if you leave your car out in the sun all day you can get enough energy for a reasonable daily commute (if you live somewhere sunny like Australia). Edit2: You actually ended up discussing the above :P
Edit3: Worth checking out the world solar challenge "cruiser class". Basically "practical" solar cars unlike the one man cockpit race vehicles of the "main event" challenger class.

[LanderMaybe]

@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.

[mikejsoames]

Take a look at the Sono Sion. It's a car made in Germany and on average will charge its own battery by 70 miles a week and 160 miles in good weather. Also costs only 25000 euros.