
Toyota is trying to put solar panels on a Prius to charge battery during the day - hhs
https://www.bloomberg.com/news/articles/2019-09-12/a-car-running-on-empty-isn-t-impossible-if-toyota-gets-its-way
======
alanh
It is so annoying when people tell me their genius idea, putting solar panels
on a Tesla. Why doesn’t Tesla already do this, they wonder? Because the amount
of energy captured by such a minuscule surface area would barely recoup the
inefficiencies of the added weight... That, and a Tesla is sexy in a way that
a vehicle plastered with solar panels would have a hard time replicating.

BTW, if you take the ferry to Alcatraz, they will try to impress with you
solar panels and a helical wind turbine on the ferry itself. But pay
attention, and they admit it doesn’t do anything more than power the
loudspeaker. The boat runs on diesel. Because of course it does. If a few
panels could power a ferry, we'd have gotten off oil long ago!

~~~
narrator
My favorite "genius idea" that comes up regularly is to have people running on
treadmills and pedaling stationary bikes use the power they generate to power
the gym or whatever. The amount of energy that treadmills and stationary bikes
can generate from human power is absolutely trivial. Even given high
electricity rates, it's worth about 3 cents an hour. The energy generated can
barely power basic electronics on most self-powered exercise bikes.

~~~
lnsru
Don’t ignore aesthetics and installation costs of plug powered gym equipment
vs. muscle powered equipment. Customer generated electricity allows to place
equipment everywhere in the gym. Gym does not need power outlets for every
piece of equipment and to have exact floor plan in the very beginning. Gym can
rearrange equipment periodically delivering better experience for clients. You
need 20 Watts to power Raspberry Pi running under load. Basic electronics with
couple LEDs need only 3-5 Watts. Even less if designed properly, so this way
generated energy can very well power gym equipment. I think, I can generate
100 Watts.

~~~
masklinn
> I think, I can generate 100 Watts.

> Over an 8-hour work shift, an average, healthy, well-fed and motivated
> manual laborer may sustain an output of around 75 watts of work.

That's before conversion & transmission losses (especially as the converter
will need to handle wildly varying inputs)

And even if we ignore these, according to 10.1109/MSPEC.2011.5910449:

> Let’s assume that the average piece of exercise equipment is in use 5 hours
> a day, 365 days a year. If each patron generates 100 watts while using it,
> that machine creates some 183 kilowatt-hours of electricity a year.
> Commercial power costs about 10 cents per kilowatt-hour on average in the
> United States, so the electricity produced in a year from one machine is
> worth about US $18 dollars.

~~~
jerf
Also, don't forget the gear to capture the electricity isn't free, is more
stuff that can break and incur maintenance fees, must contain purified metals
and other non-zero carbon emissions, and so on. Trying to break even on all of
this off of human labor is a silly game to play when there are so many other
better opportunities. And that $18/yr is already inflated by enough factors
that $1/yr is probably a much better estimate.

Same for these solar panels on a car, too. Solar panels aren't the nicest
things to manufacture right now. Putting them on a platform this poor is silly
when you could put them somewhere more effective. If they were dirt cheap and
harmless to create, opportunity costs might be less of an issue, but even
today, they aren't dirt cheap and the aren't harmless to manufacture. They
should be used effectively, not for show or feelings.

------
mdorazio
The title doesn't really tell you what they're actually doing. Toyota is
basically running a program to put 34% efficient solar panels on a Prius to
charge the battery during the day.

Using typical panels on roof, hood, and trunk only nets you 4-6 miles / day of
solar energy if you do the math. They're increasing surface area of panels
here and using what are probably multi-junction (i.e. really expensive) cells
for a fair boost in potential range / day. The claim of 18 miles per day of
sun seems like a stretch and in actual production and real-world conditions
you'd be more likely to get three quarters of that, but I could be wrong.
Still impressive, though.

~~~
not_a_cop75
5 * 365 > 1500 miles. I'd take that. And if I perchance ran out of fuel and
battery, it'd be nice to know I could eat at a cafe for an hour in the
afternoon and probably get it to hobble to a gas station.

That's the kind of peace of mind that's worth maybe an extra grand.

~~~
killjoywashere
What happens when it gets hit by a bit of flying debris on the highway?
Screwdriver, piece of wood, rock, etc? Do I have to call insurance to get the
panel replaced? Or just hail. Can I own this car in the midwest?

~~~
nexuist
Seems like an odd complaint to me. What happens if your mirror gets hit by a
rock on the highway? Or the front windshield? The solar panel is just another
part of the vehicle that can be damaged, no?

If your car is being assaulted by solid objects at highway speeds so often
that it becomes a serious concern to factor into your next car purchase, I
very strongly suggest moving somewhere safer.

~~~
adrianN
Cracks on windshields and dinged paint are cheaper to repair than high
efficiency solar panels.

~~~
kchamplewski
That's only assuming the external glass of the panel cannot be replaced
without also replacing the actual energy generating panel beneath.

------
ajuc
Kinda related: in my city they introduced regular solar cells on roofs of
public transport to charge the regular battery on ICE buses and apparently
that averages 4-5% lower fuel consumption over a year (so - all the weather
conditions, indcluding 3 months of pretty cold winter and cloudy rainy
autumn), and it makes the batteries lose capacity much slower.

These buses use batteries for lots of stuff - lights, automatic doors, AC,
ticket machines, external and internal displays. Apparently there are problems
with batteries running empty when the buses have to wait for the next course
too long. Also the batteries are losing capacity too quickly when they are
charged all the way down often.

They introduced the pilot program in 2013 and in 2017 they decided to put
solar cells on all the buses. Links in Polish:

[http://www.mpk.lublin.pl/imgs_upload/image/aktualnosci_fotki...](http://www.mpk.lublin.pl/imgs_upload/image/aktualnosci_fotki/panele_foto.jpg)

[http://www.transport-publiczny.pl/mobile/lublin-wszystkie-
au...](http://www.transport-publiczny.pl/mobile/lublin-wszystkie-autobusy-mpk-
beda-mialy-panele-fotowoltaiczne-55324.html)

~~~
reaperducer
When I lived in the America's desert southwest, the school buses were
partially solar powered. The panels weren't on the roof, though, they were
where the buses were parked. Each bus had a port on the side for hooking into
the panel grid in between runs.

I think the reason there weren't panels on the roof is because the roofs
usually had two air conditioners on them. I suspect the solar plug-in wasn't
for locomotion, but to power the air conditioners.

~~~
delfinom
Yes. It's a valid technique to keep the temperature on a fleet controlled so
you don't waste time cooling down a bus later in the day before picking up
students. Solar panels let them make it basically free. And the solar panels
on the fixed roofs of the power stations will recoup their cost over time far
longer than potential lifespan of a vehicle.

------
olefoo
This is a convenience feature for fully electric cars. Charge at home, leave
it parked at work and it recharges a fair bit. Won't make as much of a
difference on a longer road trip; but will increase the range between
mandatory recharges.

If you want you probably could go full martian if you got an external solar
array you could deploy when stopped.

The real win is going to be on mid-sized electric vans and RVs since you have
more surface area and could deploy a charging array as a canopy.

Think of a 300 ft^3 van ( about the size of a Sprinter ) with full wrap solar
panels and an additional 100 ft^2 of solar panel that could be deployed when
parked.

If you were using it as an RV you could plan on extended backcountry camping
trips without having to worry about recharging.

~~~
driverdan
Your numbers are off by a lot. A Sprinter roof is around 100ft^2 (not sure why
you're saying cubic feet, solar panels are flat and can't overlap).

I live in a 25ft shuttle bus. I have solar that covers the roof end-to-end,
1800W. It's a lot but nowhere near enough to recharge batteries to drive a
vehicle of this size any reasonable distance.

~~~
olefoo
Using cube as the size of the van, not surface.

------
hourislate
The folks that come up with photovoltaic paint are going to get very rich.

In the mean time a flexible solar charging car cover/blanket would cover the
entire area of the vehicle and could plug right into the charging port while
the car is parked. Could even be used across same size vehicles or to sell
power back to the grid (if this were available) if car is fully charged.

~~~
jossmexico
photovoltaic paint .. that could be a near future news headline

~~~
kchamplewski
It already exists.

[https://solaractionalliance.org/solar-
paint/](https://solaractionalliance.org/solar-paint/)

It just has very poor efficiency compared to panels, and so is not
economically viable and probably won't be for some time.

------
tjmc
Another thing this would be great for is pre-cooling or heating the car before
you drive it. At a CoP of 3 which is conservative for modern AC heat pumps,
the 860W of solar gives you over 2.5kW of cooling.

Even if it just tempered the air whilst parked with fan ventilation through
the cabin, it would massively lower the cabin temp which can reach over 90C in
sunny locations.

~~~
theshrike79
This has been an option for at least a decade. (My 2008 Prius has this, for
example)

The first version was just a panel that ran a fan, which ran if the inside
temp > outside temp.

The next generation had an actual separate battery for the solar panel, which
engaged the car's AC when needed.

------
zolotuke
Slide Ranch in Marin County in California has a golf cart with solar panel for
roof. The guy who drives it around ranch said last couple years he did not
have to plug his cart for charging at all. If it was in’s out of the juice he
just leaves it on the sun and comes back at the end of the day. Here is a neat
use case how this technology already works albeit he has a pretty corner case.

~~~
reaperducer
180,000 golf carts are manufactured each year, and golf carts pretty much live
in the sun. Seems like an opportunity.

~~~
Johnny555
Solar panels don't have zero environmental cost, I'd be surprised if making
them solar powered is a net environmental win, especially when you have to
build the charging infrastructure anyway, just in case the weather is not
suitable for charging.

~~~
icebraining
The extra solar panels installed on the grid to feed those carts don't have
zero environment cost either, though. And neither do the batteries required to
hold that energy until the carts are plugged-in, which would likely be at
dusk/night, when they're not in use.

(Grid solar -> grid battery -> cart battery) involves more losses than just
(cart solar -> cart battery).

------
m3adow
The Sion[1] from german car startup Sono Motors will have this. The first cars
are planned to be released in 2020.

I personally am not sold on the idea of panels on a car. The positioning will
probably be subpar to outright bad most of the time and small accident repairs
will cost more, as the panel modules will need replacements.

[1]: [https://sonomotors.com/en/sion/](https://sonomotors.com/en/sion/)

~~~
vcdimension
The Sion has other advantages apart from the solar panels; it has a socket for
charging other things (e.g. other electric cars), and custom built-in software
and smartphone app for renting it out when you're not using it. This means you
can make money from it when you're not using it.

------
daddylonglegs
This seems... OK? Solar PV panels have come down in price a lot and so the
main challenge is installation. You need to manufacture mounts, fit them to a
suitable surface and then hook them up so as to deliver the power at a time
and place where it can be used.

Most cars are outside all day long and electric cars have a big battery
sitting there, ready to accept charge. Car manufacturers are the experts at
mass-manufacturing so this is probably the cheapest and lowest impact way to
install and use some solar electricity generation. If your vision of the
future includes solar PV covering every external, manufactured surface then
this is the place to start.

Of course this doesn't do much for the range of the vehicle in question;
building and operating cars is incredibly resource intensive and is only
ameliorated by making them hybrid or electric. These panels are a concrete
reminder that we need to reduce that usage to soften the damage we're doing to
the environment.

------
75dvtwin
It would be interesting how specifically these panels are different from the
ones announced by Kia.

[https://www.driving.co.uk/news/kia-hyundai-cars-will-use-
sol...](https://www.driving.co.uk/news/kia-hyundai-cars-will-use-solar-panels-
help-charge-electric-cars/)

Kia/Hyndai panel produces 100 wh. So it would take about 27 days to charge
64Kwh battery (of course no one expects full recharge with these panels.. but
just a comparison.

I think, actually people leaving in areas prone to power outages (due to
weather, for example), would appreciate built-in solar re-charge capability of
a vehicle that can provide temporary power to household devices.

------
jvsonica
I am part of a project that electrifies refrigeration units that operate on
trucks (mainly last mile distribution of temperature-sensitive goods). We've
installed solar panels on top of the trucks before and the results were very
poor. Apart from the various problems we ran into (required thin and flexible
panels compatible with automatic car wash brushes, building shades covered the
panels in a large portion of the day, etc.) the amount of energy recovered was
still very small. Even though the actual results seem great, it's still hard
to say something about its performance in real-world usage.

------
gdubs
Where’s everyone’s passion for discovery and research? They state clearly that
this is decades off _at best_. Still cool that they’re trying. It’s through
trying that you learn things.

~~~
johnatwork
I totally agree with you, sometimes a small auxiliary tech has a breakthrough
and all of a sudden it opens up a lot of doors.

------
driverdan
I'm surprised how no one commented about the obvious problems here. These are
very expensive high output panels. The ROI would be negative. They'd add
thousands of dollars to the cost of the car. Until prices drop significantly
you won't be seeing 30%+ solar on a car soon, at least not ones with a
positive ROI.

It's far more cost effective and practical to install a stationary solar array
to recharge from.

~~~
xhgdvjky
a lot of consumer goods have negative ROI and are still very successful
products. people don't just buy things because they'll make/save money

------
AtlasBarfed
This is somewhere between a gimmick and a break-even solution for daily
driving under certain circumstances...

But it's my impression that there hasn't been an industrial-scale effort on
mobile solar panels that optimize power/weight/limited area like this. I guess
maybe some of those camping panels.

But if a car can self-power it's daily driving range, and we could get spray-
on/paint-on solar (remember that?) with functional yield at reasonable cost...
why not?

The ideal intermediate electrification step isn't all-battery, as much as I'd
like that. For "consumer" driving it's PHEVs with decent all-EV range (40-80
miles)... that maximizes the somewhat restricted (currently) battery component
mineral supply to eliminate daily driving greenhouse gas emissions.

And if a cheap solar paint can reduce the grid impact of that then why not?
Throw some research into that.

Yes, generally speaking rooftop solar will be more efficient, but I'm guessing
rooftop solar and utility solar will have plenty of uses. There's STILL coal
on the grid, and NatGas.

Hm. Perovskite spray-on solar cells... Hard to see how they avoid the
perovskite degradation when it contacts air

[https://news.energysage.com/solar-news-scientists-invent-
spr...](https://news.energysage.com/solar-news-scientists-invent-spray-on-
solar-cells/)

------
eyegor
So I see the dream here, but there's just not enough surface area for a
meaningful amount of energy generation (in car terms). I really wish more
manufacturers would use solar panels to spin up an A/C compressor or a small
heater to maintain more pleasant temps inside the cabin for when you get into
the car. I remember seeing it done as a concept a few years back, but I
haven't seen one in the wild yet. Anyone know if a manufacturer is doing this?

~~~
yule
Toyota themselves:

 _Optional features included the solar-PV roof panels to help cool the cabin
interior in summer heat_

[https://en.wikipedia.org/wiki/Toyota_Prius#Third_generation_...](https://en.wikipedia.org/wiki/Toyota_Prius#Third_generation_\(XW30;_2009%E2%80%932015\))

------
bArray
This is really not going to be charging your battery much. You can barely
justify the energy usage in creating the panels. Useless if you park in a
garage at home or at the office, or have a tree overhanging the car. The
panels themselves have a shelf life too.

I would personally prefer it if you were able to fold out panels (or for extra
points, the panels fold out themselves). I think you could quite realistically
have a large "sun roof" that folds out panels instead - then you would begin
to get some better power returns. Add to that some sun tracking and you can
massively improve your efficiency.

But really, just give owners of the car something to install on their garage
roof and a plug for the car.

------
m463
I think the problem is that you would have to park your car out in the sun.
The sun is hard on cars.

Hot temperatures are not great for batteries, and if there is ever any active
thermal management, the costs would subtract from the benefits.

Elon Musk talked about this a couple of times. At first they explored it, but
then said cars wouldn't be outdoors enough to benefit.

I _have_ wondered about solar panels on the top of trucks however. A 53'
trailer has 450 square feet of roof, which with standard panels works out to
be 6kw. Probably much more with the panels toyota is using.

It seems the Tesla Semi specs say "less than 2kwh per mile" so 3+ miles for
each hour of sunshine, more with better panels.

------
seltzered_
Previous discussion from 2.5 months ago:
[https://news.ycombinator.com/item?id=20364348](https://news.ycombinator.com/item?id=20364348)

------
danans
Even if this could eventually be done affordably, this only only makes sense
for vehicles meant to only go a short distance on electricity, like Toyota's
own Prius Prime, with it's 25 mile electric range.

If you have a longer range EV, then you need to plug in anyways to charge the
much larger battery, at which point why bother with the solar panels for
charging the traction battery?

This seems a bit like an attempt to get more out of their hybrid gasoline
powered cars, which is a technology they seem very wedded to.

~~~
kchamplewski
> If you have a longer range EV, then you need to plug in anyways to charge
> the much larger battery

Why can't you, say, have a longer range EV but only have a short commute and
so not utilise that range usually?

Surely in that scenario, solar is useful on a daily basis, but when you want
to go on a long distance journey you can still make use of the charging
facilities and longer range.

~~~
danans
Given that your short (i.e. 10 miles) commute costs about $1 in utility rate
electricity (at 20c/kWh, .5kWh/mi), to be worthwhile, the solar panels would
need to cost far less than the $2 per day that such a commute costs.
Accounting for rainy or cloudy days, and the inevitable dirtying of the solar
panels, it's unlikely to be worth the expense in economic terms, to say
nothing of the aesthetics.

It would make more sense to use the money to put solar panels on your house,
if generating your own energy for commuting is a priority.

That's why I maintain that the only value of on-car solar panels for daily
commute purposes is for hybrids with small batteries (which are Toyotas
strategy) since the alternative to electricity in that case is using petrol,
which typically costs 2x per mile compared to electricity.

------
magwa101
Toyota is a hype machine right now. They're trying to mask how they are
missing the EV opportunity which they squandered on hydrogen.

------
fuzz4lyfe
In my layman's understanding of batteries doesn't the resistance of a battery
increase with its level of charge? If so wouldn't these large batteries have
so much resistance that at a reasonable level of charge most or a large
portion of the energy would be lost as heat? Does it somehow charge individual
cells as opposed to the whole thing or am I way off base?

~~~
ansible
That's not at all how battery charging works.

Whatever the voltage output of the solar panel is, you can always step that up
or down.

The batteries go up in voltage slightly when they are charging, but not much
relatively.

For a typical LiIon cell, it may be at "0%" at 3.4V (you don't want to drain
it all the way). And "100%" full is around 4.2V.

As long as you can supply at least 4.2V, it will charge up to that point.

------
mycentstoo
I think an assumption being made is that the surface area can't increase while
the vehicle isn't moving. Maybe in the future it might be possible to have the
solar panels fold out when parked to at least 2x the surface area. If we are
rethinking the grid, I don't see why we can't rethink parking at the same
time.

~~~
NullPrefix
It could unfold vertically like a solar sail on a spaceship

------
souprock
That would do for my commute, 0.9 miles each way.

It allows running a fan in sunny weather. The more the Sun is cooking the car,
the more power there is, so that works out nicely.

It helps with long-term parking, for example at an airport. It's annoying to
return to a car that won't respond to a key fob and has lost all the settings.

~~~
cortesoft
Man your commute is that short, and you drive?

~~~
jws
I used to drive for a much shorter commute. At the time I could have been
urgently summoned to a site 30 miles away at any time so I had to be prepared.

I ran out of gas on my way home one night. If you never drive past a gas
station and only fill up every month or two it’s easy to forget.

------
shadowtree
The fun then starts when they're putting up these massive solar panels on top
of parking spaces like they do all over California right now.

The big solar cell you park under then shields the one on your roof from
charging :)

------
NoblePublius
It’s upsetting that Toyota continues to delay pure electrics with this
nonsense. They sell a hydrogen car (total scam) and hybrids that still burn
oil and require costly maintenance. Dear Toyota, please give up your dream to
delay pure electrics. You lost.

------
rock_hard
I have seen small 20-4 person art cars at Burning Man achieve and impressive
range with a solar panel on top

This is def going to be huge down the road

Unfortunately today most street cars are still way to heavy/bulky for this to
have a real impact given current solar panel efficiency

~~~
gameswithgo
>This is def going to be huge down the road

For the cost and mass of the solar panels, you can add more range with more
batteries, on normal sized street cars. The math just doesn't work out well
until you get to very small/light vehicles with large roof area.

------
joosters
I think there used to be an Audi model with a solar panel on the roof that was
used to power the aircon when parked. No idea how effective it was, but the
concept was clever, since when there was little sunlight, you wouldn’t need
the power anyway.

------
0d0d0fsd0
Seems more like a marketing stunt than anything.. Sounds like a nice idea but
the marginal benefit is likely zilch. If you're going to build solar panels,
you should put them somewhere where you're optimizing their power generation.

------
Amygaz
Blog on this topic: [https://solarhub.energy/why-dont-electric-cars-have-
solar-pa...](https://solarhub.energy/why-dont-electric-cars-have-solar-panels-
on-the-roof/)

------
algaeontoast
Napkin math on this isn't great, however, if you park your car outside
multiple days a week and don't use it every day this could be a worthwhile
upgrade.

------
vondur
What they could also do is a solar charging port, where you can plug in
external panels for charging. A lot of travel trailers have that capability.

------
colordrops
Assuming theoretical maximum effeciency for solar cells covering an entire
vehicle the size of a Prius, would that be enough for reasonable range?

~~~
outworlder
Yes.

You did not specify the time duration, though.

~~~
colordrops
30 miles total daily commute?

------
GhostVII
If, even just once or twice a week, you park it somewhere where you can plug
it in, the power you get from that will be far more than any panels on the
roof. You can take the money you saved from not putting panels on the car, and
put much larger panels on some roof or in a parking lot somewhere, where they
will be always generating electricity.

This only really makes sense if you never have access to charging, and if that
is the case an electric car is probably not a great fit for your lifestyle
anyways.

------
nottorp
Now THAT WORLD be incentive to keep my car clean!

~~~
nottorp
"WOULD" of course... damn spell checker...

------
WalterBright
I used to use a solar battery charger to keep my car battery topped up when it
was just sitting around. Worked great.

~~~
outworlder
> I used to use a solar battery charger to keep my car battery topped up when
> it was just sitting around. Worked great.

Car battery, like a lead acid one? If so, it's a very tiny battery.

~~~
fnord77
Car Trickle chargers put out very little amps. Like 1 or 2

------
neonate
[http://archive.is/qJNov](http://archive.is/qJNov)

------
songshuu
If not Toyota proper, folks have been _trying_ to put solar panels on a Prius
from about the launch.

------
iamgopal
There should be some website for telling people about logically valid stupid
idea, like making roads out of solar panel, and this, and hydrogen car. The
other day, someone suggested me to put motor on wind turbine so it can produce
more power in low wind condition. Someday, people will install wind turbine on
top of car for car charging even while driving.

------
ende
The problem with this is that we need more parking garages than open air
parking lots.

------
themattress
Very cool, but I wouldn’t want to pay to repair that after an accident. Oof.

~~~
Johnny555
You already don't want to pay for a repair for a modern car after an accident
-- all of the electronics and recalibrations (front camera and calibration,
front radar sensor and calibration, blind spot detecting radar/ultrasonic
sensor and calibration) adds up to serious money even for a minor accident.

~~~
ansible
OMG, yes! Had a cracked windshield recently, sooooo expensive

------
Siecje
What is invisible concrete?

------
ameliaquining
Obligatory [https://xkcd.com/1924/](https://xkcd.com/1924/)

------
niceworkbuddy
This is just equivalent to canister in gas-powered vehicles.

~~~
de_watcher
A small canister that is infinitely large inside, and with a very thin neck.

------
_Codemonkeyism
To sum up the comments:

Everyone commutes hours so this is not enough (as always readers assume
everyone lives in the US).

Everyone has a house so put them there (see comment about US).

Tesla doesn't have it so it doesn't make sense.

------
d--b
What is happening when the battery is full?

~~~
jacobush
The panel returns photons to the sun for storage.

------
moonbug
marketing plebdazzle for the innumerate.

------
emrullahcimen
Actually panels might be very heavy fot the car to carry but what about some
kind of nano tech which allows to absorb the energy coming from the sun and
supply it in the batteries. Yes its much complicated to do but a valuable idea
to think on.

------
whatshisface
I bet you could get a more useful vehicle by making something more efficient
than a Prius - sacrificing some niceties of course. This is a marketing stunt
for the Prius brand, but it makes me wonder what you could get if you relaxed
that constraint.

~~~
dannyw
The Prius is on the leaderboards for MPG. I don’t buy your argument.

~~~
whatshisface
Would it be on a leaderboard that included empty frames with no air
conditioning units? The Prius is nowhere near the best efficiency you can get
with a vehicle. Check out the Wikipedia page on solar cars for a couple of
pictures:

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

~~~
serf
I guess leaderboard is defined by "Cars that have sustained the rigors of
NTSB-style testing to determine roadworthiness and are available for sale to
the mass public."

Cars are nowhere near efficient, they are just in a nice point between
practicality and efficiency for their given use-cases.

~~~
a_imho
Disagree with the nice point unless we disregard all the externalized costs.

