Tesla 3 Unveiled

[aceyou]

Tesla is having a live unveiling of the model 3 tonight at 8:30 pacific time.  Most won't be interested, but just thought I'd throw it out there to anyone who is. 

I am a long ways from owning a Tesla due to a higher priority on becoming FI, but I have great respect for what Musk is doing. 

[steviesterno]

i really like the idea of an electric car, it just makes sense. more so if I could recharge from solar panels on my roof here in Texas. I know we will be going that way, and I'm sure in 3 decades that will be normal.

I'm nervous for how we get there though. for most people, their car is the most expensive thing they "own". if it's suddenly illegal or too expensive to own a gas powered car, they will have tons of money or monthly payments tied up in a car they can't drive.

I plan on driving my toyota until every car is electric. It will be paid for later this year (pre-MMM). so if it lasts another 5 years, that's all free driving and I won't be left holding the bag.

eventually cars will be covered in solar panels so you just charge as you drive and wherever you are parked. that will be sweet. road trip? Just go when it's sunny and run forever.

[Jack]

eventually cars will be covered in solar panels so you just charge as you drive and wherever you are parked. that will be sweet. road trip? Just go when it's sunny and run forever.

That will never be possible. The ratio of the car's surface area to the amount of energy it requires is too low. Even if you had a car that used the same amount of energy as a Geo Metro or large motorcycle but had the surface area of a tour bus and was completely covered in 100% efficient solar panels, it still wouldn't be enough.

[ketchup]

I'm probably two cars away from going electric.  Our current cars are gas-powered.  Their replacements will be gas-powered.  The next ones will probably be electric.  We'll see.

I am curious to see what Tesla has up their sleeve.  This one is shaping up to be a winner.  Maybe I'll buy one with a reconditioned battery pack in 2027.

[golden1]

Yeah, I am stoked about this too.  I figure I will own a car like this when my kids are out of the house in about 5-6 years.  Hopefully by then the kinks will be worked out.  I am curious what the differences (besides size) will be between this and the S. 

Another car that interests me that is coming sooner than the Tesla 3 is the Chevy Bolt.  It is small, but gets 200 mile range at a 37.5K price point before incentives.  It is also a hatchback style similar to the fit which is a great use of space.

http://www.caranddriver.com/chevrolet/bolt-ev

[Fudge102]

I love tesla's idea.  I'm sure like many people the worst part has been the price.  I myself drive a Chevy volt that I got about three years ago now.  I love never filling up on gas when I'm around town.  I only ever fill up if I'm headed away for the weekend.  I only wish it was possible to charge the car faster.  I'm not sure how they will make faster charging without damaging the battery in some fashion.  Tesla's getting there though.  I don't know why there are people who are in uproar about electric cars and their lack of "noise."  I love my quiet car.

[tobitonic]

Yeah, I am stoked about this too.  I figure I will own a car like this when my kids are out of the house in about 5-6 years.  Hopefully by then the kinks will be worked out.  I am curious what the differences (besides size) will be between this and the S. 

Another car that interests me that is coming sooner than the Tesla 3 is the Chevy Bolt.  It is small, but gets 200 mile range at a 37.5K price point before incentives.  It is also a hatchback style similar to the fit which is a great use of space.

http://www.caranddriver.com/chevrolet/bolt-ev

^ Yup...I honestly think the Bolt will do far more for the electric car industry than the 3...kind of like I think the Leaf has done more for electric car penetration than the S. The showy vehicles are nice, but the ones people can afford to buy are the ones that lead to change. Just ask Norway (they have the greatest electric car use in the world, proportionally). That said, I'm happy to see the 3 joining the field, as I am with every electric vehicle.

[Chris22]

\
^ Yup...I honestly think the Bolt will do far more for the electric car industry than the 3...kind of like I think the Leaf has done more for electric car penetration than the S. The showy vehicles are nice, but the ones people can afford to buy are the ones that lead to change. Just ask Norway (they have the greatest electric car use in the world, proportionally). That said, I'm happy to see the 3 joining the field, as I am with every electric vehicle.

I doubt the Bolt will have much impact.  And the Leaf has had some, but less than the Model S, especially given the price difference.

The problem is, the Bolt and Leaf and similar are electric cars that only electric car nerds would want.  Relatively slow, extremely unstylish/dorky, zero sex appeal.  Only the die-hard treehuggers and cheapskates want an electrified breadbox like the Leaf and Bolt.

Tesla, on the other hand, made electric cars cool and sexy and desirable on their own, not just to EV nerds.  I'm a huge car nut, and I want a Model S (P90D, please).  I'd rather chop my hand off than drive a Leaf or Bolt or similar. 

In fact, as part of my basement renovation, I'm running a 220 outlet from my fusebox to my garage thinking that in the not too distant future one of my three cars might end up being an electric. 


Electric car sales YTD Oct-15:



Source:
http://cleantechnica.com/2015/11/05/1-2-3-tesla-model-s-chevy-volt-nissan-leaf-top-us-electric-car-sales-in-october/

[MandyM]

I'm really excited to see the Model 3! Not that I will buy one anytime soon, but its another big step for EV cars. My main metric for going EV (other than cost) is: can I get to my dad's house in a reasonable amount of time? Its about 330 miles from me to him. I want to be able to make that trip either without stopping or with one 20-30 minute stop for charging. Tesla + a supercharger can do that (range of +200 miles, 170 miles/30 minutes on supercharger), but the price is still a barrier.

I hope to be one car away from an EV (I plan to keep my current car for 7-10 more years).

[golden1]

Only the die-hard treehuggers and cheapskates

37.5K for a car means you are a cheapskate now?  Lol, ok.

I just have the wildly controversial idea that paying 65K more in order to get from 0-60 in 3 seconds is not a very wise use of $$$ but whatever floats your boat I guess. 

And for all those girls having sex with guys because they have a Tesla S, shame on you! 

In all honesty, Tesla has done great work in changing the image of the electric car and doing a lot of the necessary R&D and design work to get a practical and fun model made, and for that, it deserves enormous credit.  For that reason alone, I would rather give Tesla my money than Chevy or Nissan. 

[HipGnosis]

I doubt the Bolt will have much impact.  And the Leaf has had some, but less than the Model S, especially given the price difference.

The problem is, the Bolt and Leaf and similar are electric cars that only electric car nerds would want.  Relatively slow, extremely unstylish/dorky, zero sex appeal.  Only the die-hard only die-hard treehuggers and cheapskates would want an electrified breadbox like the Leaf and Bolt.

You contradict yourself.  You say "only electric car nerds would want (EVs)", then admit that "die-hard treehuggers and cheapskates would want (EVs)".
EV's, like gas autos, need to be made / sold in various forms to meet the various needs of various (potential) buyers.

The hurdle I'm waiting for EVs to clear is:  standardized fast-charging
Then there can be stations along the highways like there are gas stations today.
I've read studies that say it's a potential $3 billion a year market - because they will have a captive customer for 30 - 45 minutes, which is a marketing golden ticket.
I've no doubt that they will find all kinds of services to offer; haircut, massage, manicure... all at a convenient price (ie profit).  I hope it makes the charging a free perk to entice customers with low resistance to immediate gratification.

[boarder42]

its not just the sales of Tesla cars that revolutionary- its the fact that everyone said electric wasnt possible b/c of infrastructure and Musk just gave them a big middle finger and built his own infrastructure.  He and his company have single handedly made electric cars a realistic and viable replacement to our mobile powerplants we currently own.  This is the beginning of the end for Gas powered Auto's IMO.  Battery packs are 12k right now for the large 85's down 65% in the last 5 years.  meaning in 10 years if that trend continues you're looking at sub 1500 dollar battery packs that can go 300+ miles. 

[Chris22]

Only the die-hard treehuggers and cheapskates

37.5K for a car means you are a cheapskate now?  Lol, ok.

It's the people who will do anything to get out of paying for gas. 

[boarder42]

I doubt the Bolt will have much impact.  And the Leaf has had some, but less than the Model S, especially given the price difference.

The problem is, the Bolt and Leaf and similar are electric cars that only electric car nerds would want.  Relatively slow, extremely unstylish/dorky, zero sex appeal.  Only the die-hard only die-hard treehuggers and cheapskates would want an electrified breadbox like the Leaf and Bolt.

You contradict yourself.  You say "only electric car nerds would want (EVs)", then admit that "die-hard treehuggers and cheapskates would want (EVs)".
EV's, like gas autos, need to be made / sold in various forms to meet the various needs of various (potential) buyers.

The hurdle I'm waiting for EVs to clear is:  standardized fast-charging
Then there can be stations along the highways like there are gas stations today.
I've read studies that say it's a potential $3 billion a year market - because they will have a captive customer for 30 - 45 minutes, which is a marketing golden ticket.
I've no doubt that they will find all kinds of services to offer; haircut, massage, manicure... all at a convenient price (ie profit).  I hope it makes the charging a free perk to entice customers with low resistance to immediate gratification.

these stations exist tesla owns them its free to charge at them(with a tesla) it takes ~15-20 minutes to get you to 80% which is enough to get to the next one.

[Chris22]

You contradict yourself.  You say "only electric car nerds would want (EVs)", then admit that "die-hard treehuggers and cheapskates would want (EVs)".

Lol, it's only a contradiction unless you don't think "electric card nerds" and "die-hard treehuggers and cheapskates" aren't all the same group.  Which I do.

Tesla's genius was that he made a sexy, desirable car that happened to be electric.  He didn't make an electric car and then try to make it desirable.  NORMAL people want Teslas, not only the traditional electric car customers (a cross section of treehuggers, cheapskates, and electric car nerds).

EV's, like gas autos, need to be made / sold in various forms to meet the various needs of various (potential) buyers.

Exactly.  And until Tesla, they basically were only made in the form of "nuclear egg-shaped shitbox."

[ketchup]

The problem is, the Bolt and Leaf and similar are electric cars that only electric car nerds would want.  Relatively slow, extremely unstylish/dorky, zero sex appeal.  Only the die-hard treehuggers and cheapskates want an electrified breadbox like the Leaf and Bolt.

Tesla, on the other hand, made electric cars cool and sexy and desirable on their own, not just to EV nerds.  I'm a huge car nut, and I want a Model S (P90D, please).  I'd rather chop my hand off than drive a Leaf or Bolt or similar. 

This is very true.  Things like this don't catch on unless they're "cool".  Losers like me don't care about that, but most do.  Tesla knows that, and is doing a great job at making EVs cool.  People like things that are cool, like smartphones, cigarettes, and fancy clothes.

[savingstldad]

The sales numbers for the various models are likely directly related to the range of those vehicles.  The reason the Bolt is such an interesting car, is that it nearly doubles the current range of every electric car available except for the Teslas.

[Chris22]

The sales numbers for the various models are likely directly related to the range of those vehicles.  The reason the Bolt is such an interesting car, is that it nearly doubles the current range of every electric car available except for the Teslas.

But it looks like a cheapass economy car like a Chevy Sonic or Ford Fiesta, meaning it will be basically salesproof.  Most people do not want a tiny hatchback.

[tobitonic]

\
^ Yup...I honestly think the Bolt will do far more for the electric car industry than the 3...kind of like I think the Leaf has done more for electric car penetration than the S. The showy vehicles are nice, but the ones people can afford to buy are the ones that lead to change. Just ask Norway (they have the greatest electric car use in the world, proportionally). That said, I'm happy to see the 3 joining the field, as I am with every electric vehicle.

I doubt the Bolt will have much impact.  And the Leaf has had some, but less than the Model S, especially given the price difference.

The problem is, the Bolt and Leaf and similar are electric cars that only electric car nerds would want.  Relatively slow, extremely unstylish/dorky, zero sex appeal.  Only the die-hard treehuggers and cheapskates want an electrified breadbox like the Leaf and Bolt.

Tesla, on the other hand, made electric cars cool and sexy and desirable on their own, not just to EV nerds.  I'm a huge car nut, and I want a Model S (P90D, please).  I'd rather chop my hand off than drive a Leaf or Bolt or similar. 

In fact, as part of my basement renovation, I'm running a 220 outlet from my fusebox to my garage thinking that in the not too distant future one of my three cars might end up being an electric. 


Electric car sales YTD Oct-15:



Source:
http://cleantechnica.com/2015/11/05/1-2-3-tesla-model-s-chevy-volt-nissan-leaf-top-us-electric-car-sales-in-october/

The S is definitely a more attractive and eye-catching car than the Leaf and Bolt. We've personally looked into the S due to its semi-autonomous capabilities (although we decided to wait for fully autonomous driving to become available, and in minivan format ideally). However, even though the S is the leader among electrics in the US, the cheaper electrics are the leaders overseas. Cheap electric cars like the i3 and Leaf are what people are buying in countries with much greater shares (3% vs .67%) of electric vehicles. http://bestsellingcarsblog.com/2016/03/norway-january-february-2016-mazda-cx-3-inside-top-10/

[savingstldad]

I actually agree with you on a personal level.  I don't really want a tiny car, but I make a good living and am in my 40's so I'm not the target market for these things.

Here are the sales numbers I see on a quick google search though:

http://online.wsj.com/mdc/public/page/2_3022-autosales.html

According to that data, year to date in 2016 there were over 400,000 small cars sold.

[Chris22]

However, even though the S is the leader among electrics in the US, the cheaper electrics are the leaders overseas. Cheap electric cars like the i3 and Leaf are what people are buying in countries with much greater shares (3% vs .67%) of electric vehicles. http://bestsellingcarsblog.com/2016/03/norway-january-february-2016-mazda-cx-3-inside-top-10/

Likely mostly due to the large form-factor of the Model S, they simply don't have space to make parking a car that large convenient overseas. 

[Chris22]

I actually agree with you on a personal level.  I don't really want a tiny car, but I make a good living and am in my 40's so I'm not the target market for these things.

Here are the sales numbers I see on a quick google search though:

http://online.wsj.com/mdc/public/page/2_3022-autosales.html

According to that data, year to date in 2016 there were over 400,000 small cars sold.

But of those "small cars" how many are of the 1-box tiny-van form, and how many are small sedans?  It's specifically the tiny-breadvan form factor most people are looking to avoid.

[tobitonic]

However, even though the S is the leader among electrics in the US, the cheaper electrics are the leaders overseas. Cheap electric cars like the i3 and Leaf are what people are buying in countries with much greater shares (3% vs .67%) of electric vehicles. http://bestsellingcarsblog.com/2016/03/norway-january-february-2016-mazda-cx-3-inside-top-10/

Likely mostly due to the large form-factor of the Model S, they simply don't have space to make parking a car that large convenient overseas.

Oh, I agree. Also, with higher fuel prices for normal (non-electric) cars, folks are already used to buying smaller cars, so it's not much of a switch.

In the US, I think the market will really take off when a.) 200+ mile ranges are standard, and b.) mid-sized cars, SUVs, and minivans are available with electric modes. The 3 will be the first mainstream mid-sized electric, so we're making progress.

[savingstldad]

Ah, I don't see it as particularly ugly compared to the Civic, Fiesta, or Sonic type cars.  I think with it's much higher range, it could do well.

[Jack]

In fact, as part of my basement renovation, I'm running a 220 outlet from my fusebox to my garage thinking that in the not too distant future one of my three cars might end up being an electric. 

Only one? When I renovate my basement/garage, I was thinking of running several: two for EV charging, one for an air compressor, and one for a welder.

But it looks like a cheapass economy car like a Chevy Sonic or Ford Fiesta, meaning it will be basically salesproof.  Most people do not want a tiny hatchback.

But of those "small cars" how many are of the 1-box tiny-van form, and how many are small sedans?  It's specifically the tiny-breadvan form factor most people are looking to avoid.

On the contrary: companies make EVs into cheap-ass economy cars because they sell better. Consider this proof by contradiction: if GM wanted, they could just as easily stick an EV drivetrain into a kappa or alpha chassis and call it a sports car. But they don't. Why? Because it would sell even worse than the Bolt will!

Incidentally, as a car guy, I actually like the 'tiny breadvan' form factor (and the more box-like, the better). Of course, I also like the idea of getting a VW Bus and putting a Porsche engine in it, which suggests that I'm really, really weird.

[Guses]

eventually cars will be covered in solar panels so you just charge as you drive and wherever you are parked. that will be sweet. road trip? Just go when it's sunny and run forever.

That will never be possible. The ratio of the car's surface area to the amount of energy it requires is too low. Even if you had a car that used the same amount of energy as a Geo Metro or large motorcycle but had the surface area of a tour bus and was completely covered in 100% efficient solar panels, it still wouldn't be enough.

Jack, never say never!

Normal maximal solar irradiation on earth is about 1000 watt per square meter. A 100% efficient panel would therefore generate as much power.

According to this study (www.mdpi.com/1996-1073/7/12/8317/pdf), the 800 KG passenger car that they modeled consumes about 2,250 watts driving at 50 Km/h per hour. It would totally be possible to drive that car at that speed using 100% efficient solar panels on the car (assuming optimal sunlight).


So yeah, when you factor in efficiency and non optimal conditions, it likely won't be possible with current technology but solar panels could still contribute a non trivial amount of energy to a car and possibly extend the range significantly.

[Chris22]

Jack, never say never!

Normal maximal solar irradiation on earth is about 1000 watt per square meter. A 100% efficient panel would therefore generate as much power.

I suppose if we repealed the first two laws of thermodynamics you could be right....

[tomsang]

Jack, never say never!

Normal maximal solar irradiation on earth is about 1000 watt per square meter. A 100% efficient panel would therefore generate as much power.

I suppose if we repealed the first two laws of thermodynamics you could be right....

What laws of thermodynamics is he breaking?  Non engineer here, so not attacking.  Seems like there currently is 100% electric test vehicle out there today.  Solar cells are only capturing like 20% of the energy.  Electric engines and battery technology are making huge leaps in efficiency.  Car design and structures can be revolutionized with 3d printing and highly engineered ways to reduce weight considerably.     

[zephyr911]

eventually cars will be covered in solar panels so you just charge as you drive and wherever you are parked. that will be sweet. road trip? Just go when it's sunny and run forever.

That will never be possible. The ratio of the car's surface area to the amount of energy it requires is too low. Even if you had a car that used the same amount of energy as a Geo Metro or large motorcycle but had the surface area of a tour bus and was completely covered in 100% efficient solar panels, it still wouldn't be enough.

Jack, never say never!

Normal maximal solar irradiation on earth is about 1000 watt per square meter. A 100% efficient panel would therefore generate as much power.

According to this study (www.mdpi.com/1996-1073/7/12/8317/pdf), the 800 KG passenger car that they modeled consumes about 2,250 watts driving at 50 Km/h per hour. It would totally be possible to drive that car at that speed using 100% efficient solar panels on the car (assuming optimal sunlight).


So yeah, when you factor in efficiency and non optimal conditions, it likely won't be possible with current technology but solar panels could still contribute a non trivial amount of energy to a car and possibly extend the range significantly.

There's a VIA truck out with a solar tonneau cover that can add something like 5 miles of range in a long, sunny day. The panels probably have over 50% of the theoretical maximum efficiency, so let's say generously 10 miles. Take a much smaller and lighter vehicle, make it 20. That's half of the 80th percentile commute that the Volt was designed for. I'd call it meaningful but it'll never eliminate the need for onboard storage or for grid power, nor is there much economic or environmental incentive to do so. Grid power is cheap and plentiful, and getting cleaner all the time, and batteries are rapidly improving (pretty much every month something better comes to market). And EV TCO is already better than ICE, with purchase price parity single-digit years away.

Most people who drive electric and are concerned about grid issues just add solar at home. The grid is a much more efficient and cost-effective power bank than a battery mounted in your car.

@Chris22: I think you're partially right about the Bolt, but I know plenty of EV people who are excited about it, and it is much quicker than all the current economy EVs - 0-60 in just over 6 seconds. A Tesla 60 is only a fraction of a second quicker. As for aesthetics... a lot of the concepts look pretty boring but the last pre-production pic I saw actually actually looked like a decent hot hatch. I am considering buying one.

[Chris22]

Jack, never say never!

Normal maximal solar irradiation on earth is about 1000 watt per square meter. A 100% efficient panel would therefore generate as much power.

I suppose if we repealed the first two laws of thermodynamics you could be right....

What laws of thermodynamics is he breaking?  Non engineer here, so not attacking.  Seems like there currently is 100% electric test vehicle out there today.  Solar cells are only capturing like 20% of the energy.  Electric engines and battery technology are making huge leaps in efficiency.  Car design and structures can be revolutionized with 3d printing and highly engineered ways to reduce weight considerably.   

100% efficient panel. 

1.  "you can't win"
2.  "you can't break even"

Basically, 100% efficiency is impossible.  I'm not sure how efficient we are currently with panels, but anything that starts with "well, a 100% efficient..." is just not going to work.

[Jack]

eventually cars will be covered in solar panels so you just charge as you drive and wherever you are parked. that will be sweet. road trip? Just go when it's sunny and run forever.

That will never be possible. The ratio of the car's surface area to the amount of energy it requires is too low. Even if you had a car that used the same amount of energy as a Geo Metro or large motorcycle but had the surface area of a tour bus and was completely covered in 100% efficient solar panels, it still wouldn't be enough.

Jack, never say never!

Normal maximal solar irradiation on earth is about 1000 watt per square meter. A 100% efficient panel would therefore generate as much power.

According to this study (www.mdpi.com/1996-1073/7/12/8317/pdf), the 800 KG passenger car that they modeled consumes about 2,250 watts driving at 50 Km/h per hour. It would totally be possible to drive that car at that speed using 100% efficient solar panels on the car (assuming optimal sunlight).


So yeah, when you factor in efficiency and non optimal conditions, it likely won't be possible with current technology but solar panels could still contribute a non trivial amount of energy to a car and possibly extend the range significantly.

800 kg is 1764 lbs, or slightly heavier than a 1990 Geo Metro (and lighter than even a Mazda Miata). And that's before you add any passengers or cargo. And don't forget range issues! You'd still need batteries for our hypothetical car (in order to do things like drive at night), and those still add weight. Let's assume a realistic minimum laden weight is more like 2600 lbs, or about 1.5x the car in the study. Power required increases linearly with mass, so a car weighing 1.5x more would need 1.5x more power.

50 km/h is 31 mph, or about half as fast as the car would need to go to keep up with normal traffic. Note that the power required to overcome drag increases with the cube of the velocity, which means that the power required to go 60 mph is 8x more than the power required to go 30 mph.

If we multiply the weight and drag factors together (which is a wild and reckless simplification, but probably good enough for a forum post), it seems like we need 12x as much power than the study assumes, which means we'd need 12x as much surface area for the solar panels. The car in the study actually needed 2250 watts and you assumed the panels produced 1000 watts per m², so it would need 2.25 m² and our realistic car would need 27m²

A Cadillac Fleetwood, one of the largest sedans ever made, measured 78" wide and 225" long. Translated to metric, that's roughly 2m * 5.7m = 11.4m² of projected surface area -- not enough, even before you subtract to account for things like the sloping windshield and the fact that no realistic car would be perfectly flat and rectangular.

Jack, never say never!

Normal maximal solar irradiation on earth is about 1000 watt per square meter. A 100% efficient panel would therefore generate as much power.

I suppose if we repealed the first two laws of thermodynamics you could be right....

What laws of thermodynamics is he breaking?  Non engineer here, so not attacking.

The first and second laws, as the GP stated. They can basically be summed up as "100% efficiency is impossible."

[tomsang]

Thanks for the thermodynamic education.  Considering that there currently is 100% all electric powered cars today and today's solar cells, batteries, electric engines, and cars are not currently overly well designed or efficient.   Doesn't that indicate that there is a feasible way to make 100% electric cars sometime in the future?

[Jack]

There's a VIA truck out with a solar tonneau cover that can add something like 5 miles of range in a long, sunny day. The panels probably have over 50% of the theoretical maximum efficiency, so let's say generously 10 miles. Take a much smaller and lighter vehicle, make it 20. That's half of the 80th percentile commute that the Volt was designed for. I'd call it meaningful but it'll never eliminate the need for onboard storage or for grid power, nor is there much economic or environmental incentive to do so. Grid power is cheap and plentiful, and getting cleaner all the time, and batteries are rapidly improving (pretty much every month something better comes to market). And EV TCO is already better than ICE, with purchase price parity single-digit years away.

Sure, you can chip away at the problem with solar panels -- nobody's disputing that. But steviesterno is expecting a Sunraycer-esque "drive all day using only solar power" experience (but with normal-compact-sedan practicality), and that's the hope I had to dash.

Thanks for the thermodynamic education.  Considering that there currently is 100% all electric powered cars today and today's solar cells, batteries, electric engines, and cars are not currently overly well designed or efficient.   Doesn't that indicate that there is a feasible way to make 100% electric cars sometime in the future?

There are 100% electric cars now. 100% solar cars are impossible because the solar irradiance isn't high enough (as I proved the long way around above). If we lived on Mercury (9116.4W/m²), it might be possible, but not on Earth.

[Chris22]

Sure, you can chip away at the problem with solar panels -- nobody's disputing that. But steviesterno is expecting a Sunraycer-esque "drive all day using only solar power" experience, and that's the hope I had to dash.

I think Toyota does some cool things with solar panels that make a lot more sense, such as having panels built into the roof of the Prius to power a small fan that keeps the cabin ventilated, so it stays cooler in the sun and the HVAC doesn't have to work as hard to cool it off, that sort of thing.  Those are ideas that will help the efficiency of electric cars, and are highly encouraged, but the idea of just powering a car via car-mounted solar is not going to happen.  But things like home-mounted solar arrays storing in a Tesla battery pack at home that is then used to charge the car, that is very viable and makes a lot of sense.

[tomsang]

There are 100% electric cars now. 100% solar cars are impossible because the solar irradiance isn't high enough (as I proved the long way around above). If we lived on Mercury, it might be possible, but not on Earth.

Again not an engineer, but if there currently is 100% solar cars today.  And if technology is improving daily for solar cells, batteries, car design, etc.  How can you say it is impossible in the future, when it is currently happening today?

These 100% solar cars are currently using cells that are 30% efficient.  They should be improving yearly until they reach their limits of 100% 

[CmFtns]

It seems like we need 12x as much power than the study assumes, which means we'd need 12x as much surface area for the solar panels.

I don't think this can be even close to true because a tesla model s with a 250 mile range at interstate speeds can't go 3000 miles at 30 mph

I think it looks more like:

[Chris22]

There are 100% electric cars now. 100% solar cars are impossible because the solar irradiance isn't high enough (as I proved the long way around above). If we lived on Mercury, it might be possible, but not on Earth.

Again not an engineer, but if there currently is 100% solar cars today.  And if technology is improving daily for solar cells, batteries, car design, etc.  How can you say it is impossible in the future, when it is currently happening today?

These 100% solar cars are currently using cells that are 30% efficient.  They should be improving yearly until they reach their limits of 100%

There aren't. At least not real ones that can be used as real cars for real people and meet real safety, durability, etc requirements.

[tomsang]

Article from 9 months ago on an electric car.  It will be interesting to see how much progress they have made since the last competition.
http://www.businessinsider.com/this-solar-powered-car-can-travel-more-than-600-miles-with-one-charge-2015-7

[AZDude]

I think solar energy powering the car as you drive is probably impossible, but the idea of ubiquitous solar with charging stations all over the place, so the car charges while you shop for groceries, sit at work, etc... is very possible. Here you already see solar panels in parking lots gaining popularity since its a double-win(shade for the car, power for the business). Just add charging stations to the equation and we are that much closer.

[RWD]

There are 100% electric cars now. 100% solar cars are impossible because the solar irradiance isn't high enough (as I proved the long way around above). If we lived on Mercury, it might be possible, but not on Earth.

Again not an engineer, but if there currently is 100% solar cars today.  And if technology is improving daily for solar cells, batteries, car design, etc.  How can you say it is impossible in the future, when it is currently happening today?

These 100% solar cars are currently using cells that are 30% efficient.  They should be improving yearly until they reach their limits of 100%

Solar "car" might be a bit of a stretch. Most look like just a solar panel with wheels attached... They are also not going to work very well when it isn't sunny.


Very cool, but hard to imagine scaling up to something that seats four to five people and their luggage while meeting crash (and other) regulations.

[Jack]

It seems like we need 12x as much power than the study assumes, which means we'd need 12x as much surface area for the solar panels.

I don't think this can be even close to true because a tesla model s with a 250 mile range at interstate speeds can't go 3000 miles at 30 mph

That's why I called it "a wild and reckless simplification." The calculation doesn't work in reverse because there are other factors, such as mechanical friction within the drivetrain and between the wheels and the road, the need to accelerate (including stopping and turning), etc. that dominate the equation (instead of drag dominating) at low speeds.

[zephyr911]

Sure, you can chip away at the problem with solar panels -- nobody's disputing that. But steviesterno is expecting a Sunraycer-esque "drive all day using only solar power" experience (but with normal-compact-sedan practicality), and that's the hope I had to dash.

Absolutely.
I do think you could make a golf cart 100% solar-electric with a pretty small/cheap battery, because they spend most of their time sitting outdoors, drive only short distances at low speeds, and already have a huge flat roof covering almost the entire vehicle footprint. No other feasible applications come to mind.

There are 100% electric cars now. 100% solar cars are impossible because the solar irradiance isn't high enough (as I proved the long way around above). If we lived on Mercury (9116.4W/m²), it might be possible, but not on Earth.

The other thing that needs to be made clear is, if the idea was to eliminate the need for a large battery with all this solar power, that hope represents a lack of knowledge about how the whole system functions. Even if your panels can provide the total *average* power for a day's driving, the instantaneous power output requirements of an average vehicle are many times higher (100x or more) than the average power requirement, and you need a buffer to provide the energy for that. You also need that buffer for regenerative braking because it accounts for a large portion of the efficiency of today's EVs. The charge/discharge rate of a battery pack is limited by its size. So, you never get away from needing double-digit kWh battery capacity to power an average consumer vehicle. But that capacity is getting so cheap and easy to make that it will soon disappear as a design (and cost) constraint.

Sure, you can chip away at the problem with solar panels -- nobody's disputing that. But steviesterno is expecting a Sunraycer-esque "drive all day using only solar power" experience, and that's the hope I had to dash.

I think Toyota does some cool things with solar panels that make a lot more sense, such as having panels built into the roof of the Prius to power a small fan that keeps the cabin ventilated, so it stays cooler in the sun and the HVAC doesn't have to work as hard to cool it off, that sort of thing.  Those are ideas that will help the efficiency of electric cars, and are highly encouraged, but the idea of just powering a car via car-mounted solar is not going to happen.  But things like home-mounted solar arrays storing in a Tesla battery pack at home that is then used to charge the car, that is very viable and makes a lot of sense.

That 50W solar roof is a total and complete gimmick. It adds weight and cost, it's far less efficient and cost-effective than a rooftop panel, and I am firmly convinced it only exists for eco-braggin' rights. The actual AC uses at least 10x the power the panel provides.

My wife's Prius has one btw... lol

[JZinCO]

I think the math could be done pretty simply, yeah?

A few inputs: Area of a vehicle, energy required as a function of vehicle velocity, solar irradiance, solar panel efficiency.
We could plug a few values in. Let's say we are in New Mexico, so irradiance ranges from 3 to 8 kWhr /m^2 per day depending on the month. Solar panel efficiency is around 20% now with a theoretical maximum of 33% (at 300K) for single-junction pv cells.

For some rough math, the avg car uses 40 kwHr/day. That means, in July, we only need about 15 sq m of PV area to run a car :) And in Seattle, in the winter, we only need 169 sq m

Side note, I have a PV panel on my vehicle but the power output is only strong enough to prevent battery drain during long-term storage.

[Chris22]

That 50W solar roof is a total and complete gimmick. It adds weight and cost, it's far less efficient and cost-effective than a rooftop panel, and I am firmly convinced it only exists for eco-braggin' rights. The actual AC uses at least 10x the power the panel provides.

My wife's Prius has one btw... lol

I'll admit I've not experienced it, just read about it.  I didn't think it powered the AC, just a ventilation fan.

[CmFtns]

Well here's an example of how a solar assisted roof helps... car company failed in 1 model year
https://en.wikipedia.org/wiki/Fisker_Karma

The Karma includes as standard[26] a solar paneled roof manufactured by Asola Advanced and Automotive Solar Systems GmbH, a Quantum Technologies affiliate,[27] to aid the cabin climate control system. The solar roof is capable of generating a half kilowatt-hour a day[28] and was estimated to provide up to 4 to 5 miles (6.4–8.0 km) of additional range a week assuming continuously sunny days;[29] however, the solar panels as delivered only recharge the 12-volt lead-acid accessory battery.

[tomsang]

We started off this theoretical side thread with Steviesterno's quip, "eventually cars will be covered in solar panels so you just charge as you drive and wherever you are parked. that will be sweet. road trip? Just go when it's sunny and run forever. "

I think it has been proven that this is possible today, except the run forever part.  I am not sure what road trip a person would be doing that they need to be driving 24/7.

I linked a 4 person car that can go 800 miles currently with solar and charge or 250+ with just solar.  It is a prototype and one that they are improving on a daily basis.  What does the future hold? 

I think it is strange to say that it is impossible to make a car as Steviesterno described when it currently exists and is getting better on a daily basis.  If you put a ton of expectations on the car, then of course we will never be able to meet your definition.  It can't drive 24 hours a day, can't drive at 100 miles an hour, can't tow a camper, etc. 

But a Mustachian driver, could take this current model and go on an epic road trip with his/her three best friends cruising along at 77 miles per hour.

Topspeed has a nice article on the car:

http://www.topspeed.com/cars/others/2016-stella-lux-ar170346.html

"Bear in mind, too, this is a full-race scenario. Top speed, all day, with no chance to stop and recharge in the sun; hence the recharges, as previously mentioned. In real-world conditions, the Stella’s massive solar array would be easily capable of charging the car’s 15 kWh battery pack in 30 to 45 minutes of being parked, sitting in traffic, or tooling around town at low speed. That’s less than an hour in the sun, and you’ve got more than 600 miles of range on tap. Nevermind the fact that the sun would continue to charge it as you drove."

[tobitonic]

We started off this theoretical side thread with Steviesterno's quip, "eventually cars will be covered in solar panels so you just charge as you drive and wherever you are parked. that will be sweet. road trip? Just go when it's sunny and run forever. "

I think it has been proven that this is possible today, except the run forever part.  I am not sure what road trip a person would be doing that they need to be driving 24/7.

I linked a 4 person car that can go 800 miles currently with solar and charge or 250+ with just solar.  It is a prototype and one that they are improving on a daily basis.  What does the future hold? 

I think it is strange to say that it is impossible to make a car as Steviesterno described when it currently exists and is getting better on a daily basis.  If you put a ton of expectations on the car, then of course we will never be able to meet your definition.  It can't drive 24 hours a day, can't drive at 100 miles an hour, can't tow a camper, etc. 

But a Mustachian driver, could take this current model and go on an epic road trip with his/her three best friends cruising along at 77 miles per hour.

Topspeed has a nice article on the car:

http://www.topspeed.com/cars/others/2016-stella-lux-ar170346.html

"Bear in mind, too, this is a full-race scenario. Top speed, all day, with no chance to stop and recharge in the sun; hence the recharges, as previously mentioned. In real-world conditions, the Stella’s massive solar array would be easily capable of charging the car’s 15 kWh battery pack in 30 to 45 minutes of being parked, sitting in traffic, or tooling around town at low speed. That’s less than an hour in the sun, and you’ve got more than 600 miles of range on tap. Nevermind the fact that the sun would continue to charge it as you drove."

You nailed it.

Also, love this shot:

[boarder42]

that car doesnt charge as fast as that quote you have says.  it takes 12 hours to charge those batteries on sun alone its pretty simple math to figure that out, the time to charge quoted is using grid power not solar power. the author doesnt know what he is saying. 

[Chris22]

It's also all aluminum and carbon fiber.  I'm sure it's very affordable. 

[beltim]

We started off this theoretical side thread with Steviesterno's quip, "eventually cars will be covered in solar panels so you just charge as you drive and wherever you are parked. that will be sweet. road trip? Just go when it's sunny and run forever. "

I think it has been proven that this is possible today, except the run forever part.  I am not sure what road trip a person would be doing that they need to be driving 24/7.

I linked a 4 person car that can go 800 miles currently with solar and charge or 250+ with just solar.  It is a prototype and one that they are improving on a daily basis.  What does the future hold? 

I think it is strange to say that it is impossible to make a car as Steviesterno described when it currently exists and is getting better on a daily basis.  If you put a ton of expectations on the car, then of course we will never be able to meet your definition.  It can't drive 24 hours a day, can't drive at 100 miles an hour, can't tow a camper, etc. 

Using that article to prove your point is like using this article to say we should expect gasoline cars to get >2500 miles per gallon.