
Light Year One - cvaidya1986
https://newdawn.lightyear.one/
======
bkanber
I want them to succeed, but it will be difficult. Looks like they're following
Tesla's model of starting with the top-of-market so they can "fundraise" via
early adopter sales. Will they ever be able to hit mass production? Not sure.

In-wheel motors are interesting. That changes the dynamics of the vehicle by
adding what we mech-e's call "unsprung mass". Vehicle handling takes a huge
hit. There's a reason there are no cars on the market with in-wheel motors at
present. Additionally, you're putting expensive components in a place where
they can be more easily damaged. There's also the fact that in-wheel motors
can be very dangerous if there's a failure of the control system. Since there
are no cars on the road like this, I'm wondering if the team truly has the
expertise to tackle these issues.

But I'm not trying to be a cynic. I spent 8 years as a mechanical engineer
designing hybrid and electric cars; these are simply challenges that need to
be engineered around. This is a cool car, and I hope it makes it to market. We
need more of this.

~~~
gnode
To save others time, "unsprung mass" is the mass of the vehicle not supported
by suspension.

Lightyear's claim is that putting the motors in the wheels improves control.
Could it be that unsprung mass is reduced by negating the axle?

~~~
bkanber
I would bet that there's more unsprung mass in this configuration, but it's
hard to say without knowing the details of the motors themselves. If each
motor is, say, 80 pounds or heavier, then this configuration would likely
increase the unsprung mass.

Note a distinction between "control" and "handling". Four in-wheel motors will
have better control but worse handling. Traction control can be applied to
each individual motor, improving control in some cases, but on bumpy or rough
roads the car will experience worse handling, as the wheels will "hop" off the
surface more.

Imagine a car driving over a speed bump a little too fast. In a standard
suspension, the wheels are light enough that the suspension pushes them back
down to the road surface very quickly at the far end of the bump. If there is
more unsprung mass, however, the wheels have more inertia, and so the
suspension is not able to push the wheels down to the surface as quickly. Now
imagine that same car taking a fast turn on an uneven road surface. If the
wheels aren't pressed down to the surface after coming up off a bump, that
wheel will lose traction, and traction is required for sticking the turn. In
that case, no amount of traction control can make up for the loss of friction.

~~~
gnode
> If each motor is, say, 80 pounds or heavier, then this configuration would
> likely increase the unsprung mass.

Apparently, the motor on the Tesla Model S is 70 lbs (
[https://chargedevs.com/newswire/elon-musk-cooling-not-
power-...](https://chargedevs.com/newswire/elon-musk-cooling-not-power-to-
weight-ratio-is-the-challenge-with-ac-induction-motors/) ). With
individualized motors, each would likely be less than this. Combined with the
battery weight attached to the car's chassis, I would expect this to result in
a lower ratio of unsprung mass to sprung, and thus better handling than
typical on a non-battery car.

~~~
solarkraft
> better handling than typical on a non-battery car

Is that their main competition, though?

~~~
gnode
I mean that if it's better than what is typical, then it shouldn't be
inadequate, and that helps justify this trade-off in favour of efficiency /
range.

------
skrebbel
I live in the area and I know some people who know some of the people behind
this. My impression is that they're for real. It's not just a marketing pitch
or a pretty piece of plastic with a fundraiser, they're actually building a
proper solar car.

Parts of the team behind it was part of a university challenge team called
"Solar Challenge" and won it a few times. They drove that car through
Australia the fastest without fuel of charging. That car was ugly and
uncomfortable though.

All that said, I strongly doubt they'll ever be able to spin up production. I
bet that everybody's best case scenario is they produce a few cars that don't
totally suck and kinda/sorta make good on the efficiency / usability claims,
and then some automotive bigco acquires them.

~~~
evolve2k
You’d be referring to the World Solar Challenge a “biennial road race covering
3,022 km (1,878 mi) through the Australian Outback”. Basically running across
Australia North to South.

[https://en.m.wikipedia.org/wiki/World_Solar_Challenge](https://en.m.wikipedia.org/wiki/World_Solar_Challenge)

~~~
skrebbel
Yep, thanks!

------
pmorici
Seems like they are sacrificing performance for efficiency. They are claiming
per mile efficiency 3x better than a Tesla Model 3 but their 0-60 spec is 3x
slower than the Model 3.

The idea that a car could charge itself from integrated solar panels enough to
cover the distance of the average daily driving is interesting but you would
think Tesla thought about this and decided the math didn't work or they would
already be doing it. They are in the solar power business as well after all.

~~~
tinus_hn
That doesn’t matter as long as there is a ‘sports’ mode that sacrifices
efficiency for performance. Most times you don’t need the range anyway.

~~~
pmorici
They list their 0-60 performance at 10 seconds. That's the typical
acceleration of an average mini van. Seems unlikely you would put that in the
specs if you could magically flip a switch and get 3x better.

~~~
ZeroGravitas
As someone who is not a car guy, but interested in EVs this is a good sign to
me.

Tesla has done great work in exploring the space of how you make an EV that
impresses Top Gear viewers.

I'm also interested in seeing similar progress for people who just want to get
from A to B cheaply and efficiently and sadly few of the existing car makers
seem to be taking EVs seriously yet. I've often thought that a different set
of assumptions (e.g. not caring about topspeed) might lead to a better overall
car, sounds like they are exploring this area.

------
dmitrygr
Predictably, the math does not work.

They say that at 3.7KW it gains range at 35km/h, and from solar it gains range
at 12km/h. This means that they expect to get 1.23KW of power from their solar
cells. Top theoretical efficiency possible for any solar cell is about 33%
(Shockley-Queisser limit), most efficient you can buy today is 22%. So that
means they expect 5.59KW of sun energy to fall on the car per square meter. A
typical car is 4.5x2 meters. Let's assume they tile the whole damn thing with
highest efficiency cells except the windshield (1x2m) They then have 7m^2, so
they expect solar energy to provide 799W/m^2. And it is true, sunlight
reaching earth is about 1KW/m^2 at the equator in noon, but that is in perfect
conditions and just there, and when cell is perfectly aimed at the sun. The
car will not tilt, and some days there are clouds or haze, and we do not all
live at the equator. Also, in fact, not the entire car can be tiled with solar
cells, and dirt exists, especially on the road.

So the numbers they promise are pretty much _at the very limit_ of
_theoretical_ possibility _in ideal conditions_ , and not even remotely likely
to be hit in real life.

~~~
nudded
I think I miss something in your numbers. They say 83 Wh/km. which means that
they expect to get 996Wh in an hour. How did you reach 5.59KW?

~~~
dmitrygr
i am analyzing charging rates. they cite charge rate in km/h for an outlet
providing 1.3KW and they cite a charge rate for solar, from which we can work
out the power they expect to get from solar

~~~
nudded
I see, but that does not answer my question though. How is my math wrong? the
expected range from solar in 1 hour equates to 996 Wh. You suggest they need
5.6kW of solar to achieve this?

~~~
dmitrygr
you are forgetting that solar cells are not 100% efficient, and charging is
not either. so you MUST use charge rates cites, not consumption rates

~~~
nudded
No, you must not. The energy required for the car to drive 12kms is 996 Wh.
let's round to 1kWh.

Solar is DC. for instance Tesla powerwall is 97% efficiency for DC/DC
conversion for charging its battery. So you need basically 1kW of solar to
produce the needed energy to drive 12km (per hour). I think you are off by at
least a factor of 3.

edit: at 20% solar efficiency that would require 5m^2.

~~~
dmitrygr
so then your claim is they lose 66% on rectification of AC when they charge
from a wall? :)

~~~
nudded
No, my claim is that their solar claim is not ridiculous ;)

Also, if I do the math on their AC charging. 35km/h gained --> 2905Wh energy.
Standard 230AC, 16 amps is 3680W. So I guess the number there is also correct?
Take about 85% efficiency, then you have 3000Wh in one hour from 230V AC

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nwah1
I looked into the idea of solar panels on cars, to figure out why they don't
do that.

Turns out it would add only a trivial amount of energy, and thus is just a
gimmick.

>Although the energy from the solar panel might seem like a large value, it's
only 2 percent of the total battery energy.

[https://www.wired.com/story/could-tesla-power-its-
electric-t...](https://www.wired.com/story/could-tesla-power-its-electric-
truck-with-solar-panels/)

~~~
bkanber
I agree it's a gimmick -- a very expensive one. That said, it can offset the
energy required to run climate control, and if you're leaving your car parked
in the sun daily, it can add up. So I'm not willing to dismiss the idea out-
of-hand. Somebody needs to try it, sometime. Glad they are.

~~~
nwah1
If and when solar paints and solar windows become super cheap, then it would
make sense to slap some on.

But at the moment, panels are expensive and would add weight, which offsets
much of the benefit.

I do want such ideas to succeed, but this is about as credible as a
cryptocurrency whitepaper.

~~~
bkanber
The weight is saved by using in-wheel motors, no axle, no differential, and so
on.

It's definitely a gimmick, but I'm not willing to dismiss them out-of-hand.
I've designed and built several hybrid and electric cars with teams 1/4 of
this company's size, so I don't take issue with the design or their ability to
build 1 or 100 units, but rather their ability to actually bring this thing to
market and be successful.

------
jellicle
If you want to see actual solar cars, you're looking at something like this:

[https://www.cbc.ca/news/canada/toronto/toronto-
engineering-s...](https://www.cbc.ca/news/canada/toronto/toronto-engineering-
solar-vehicle-unveiling-1.5187413)

Car is extremely light (you can pick it up), spindly, aerodynamic, has none of
the roadworthy safety features, uses all energy for driving (no AC,
headlights, etc.). These compete in the World Solar Challenge and manage a
good speed (50 mph) over long distances powered by the sun. This is a good
example of what is possible.

There is _no way_ that a "traditional" car, carrying five, spare tire, safety
features, headlights, bluetooth, cup holders, with apparently less solar
surface area, is going to manage any sort of respectable distance or velocity
powered by the sun alone.

~~~
riezebos
Actually the team behind lightyear won that competition last year in the
"cruiser" class carrying 4 people and having various features that you
mention. (look for "Stella lux")

~~~
markus92
They actually won it 3 times in a row, with road legal vehicles (all of them
got a license plate and thus passed the tests!). They know what they're doing.

------
dpflan
This reminds of the Solar Car Challenge. I remember watching videos many years
ago about the cars.

>
> [https://en.wikipedia.org/wiki/World_Solar_Challenge](https://en.wikipedia.org/wiki/World_Solar_Challenge)

>
> [https://en.wikipedia.org/wiki/The_Solar_Car_Challenge](https://en.wikipedia.org/wiki/The_Solar_Car_Challenge)

~~~
ragebol
The team behind Lightyear won that competition a couple of timer in the
Cruiser division with the Stella [0] car

[0]
[https://en.wikipedia.org/wiki/Stella_(solar_vehicles)](https://en.wikipedia.org/wiki/Stella_\(solar_vehicles\))

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chadwilken
Is it just me or this is thing ugly? I think the price tag associated with it
will make it hard for most to justify when you can, in my opinion, get a much
better-looking car for less money that has a proven track record and
AutoPilot. I am happy to see more EV companies popping up, but I think they
need a consumer grade car or something really game-changing to get their
start.

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LeoPanthera
A button which when clicked launches an unexpected full-screen video is an
unwelcome development in web dev.

~~~
thesimp
Indeed, this is something that needs to be blocked asap by ublock origin or a
browser setting. Taking over my screen full-screen with whatever they want to
stream to me.. ??? I'm already thinking about streaming a full-screen image of
a generic Windows desktop with a Chrome browser. Just to trick people into
thinking they are not looking at a full screen video.

Lesson for web designers: do not do this. Now we are talking about a silly web
feature while we are supposed to look at whatever message your website is
trying to convey.

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sprafa
Looks cool, but in Brighton UK it promises me 56km a day in summertime.
Seems... not a lot?

 _edit_ my bad this is how much extra it would charge a day. Seems like it
could hold an 800km charge which is incredible.

Opinion: Tesla should buy them.

~~~
morsmodr
I am sure Tesla has already put in an order to first buy one of these cars.
See whether there is any significant leg up that their own car making team can
get by buying lightyear or not. Reason being, Tesla themselves could already
be working on a car design with solar panels, not as primary source of power,
but just to help squeeze out a little more mileage

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kpwags
So I guess this car can't be garage kept?

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lallysingh
Looking at it, the "oh duh" moment really hits. Why don't more EVs have solar
hoods?

~~~
LeoPanthera
Because the sun provides a tiny fraction of the power required to be vaguely
useful, plus, solar panels are heavy, reducing the efficiency of the car.

~~~
Someone
Panels are heavy, cells aren’t. In the extreme
([https://en.wikipedia.org/wiki/Thin-
film_solar_cell](https://en.wikipedia.org/wiki/Thin-film_solar_cell)) _”Film
thickness varies from a few nanometers (nm) to tens of micrometers (µm)”_

That still has to be mounted on something, but that something easily could be
the car’s structure (and it is. The site says _”The roof and hood of Lightyear
One comprise of five square meters of integrated solar cells within safety
glass”_ )

But yes, the power budget still will be small.

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drivingmenuts
Now, that is the car company that Apple needs to buy, if they’re really going
into that sort of thing.

~~~
spbyrne
What, one that's completely unproven with no customers or product? Seems like
an odd choice for Apple, but I'd like to hear your argument.

