For centuries now, countless inventors and innovators have tried to harness the power of the
Sun. Some time in the next century, solar energy might make a large contribution to energy needs.
And today, the dream of using solar energy to power transportation is pushing automotive
technology to its limits. It was right around late 2005 where I became obsessed with the very
idea of this vehicle. By building a solar car, you'll get this constraint that you're limited
in the amount of energy you have. But building a practical solar car--one that can actually compete
with fossil fuel vehicles and today’s EVs--has never really seemed possible. Until now.
So it started out of my garage like lots of Southern California companies do. Aptera
was really started, based on obsession with efficiency.
Yeah, so actually it all started back in 2012 when the CEO of--of Lightyear
gave me a call and then he told me, yeah we're going to participate in the World Solar Challenge.
For years now, these two have been driven to build the world’s first commercial solar-powered car.
Yeah, so I'm Arjo van der Ham, co-founder and chief technology officer at Lightyear. My name is
Steve Fambro, and I'm the co-CEO of Aptera Motors. What Aptera and Lightyear are working on could
revolutionize the auto industry and transform transportation. The Lightyear One is a solar
powered family car. It has five seats. It has a five square meter solar panel. Aptera is a solar
electric vehicle that has solar cells on virtually every square meter surface of the vehicle.
Now, you may have already seen solar cars with similar out-of-this-world designs before. But
these vehicles aren’t just attention-grabbing concept cars or experimental solar racers built
for competition. These cars are designed and engineered for the everyday commute.
Having the solar cells on the vehicle lets us park it in the Sun and charge it while you're at work,
while you're shopping, or whatever. So, if you drive 12,000 miles per year, something like that like most people do.
you might never have to plug it in at all. You might just drive to work and back,
and the car pretty much stays full. You can drive about 10,000 miles a year in the Bay Area on
the power of the Sun. And I think the average person in that area drives about 13,000 miles
a year. That's already about 70% of the typical usage. So while you can plug in to recharge these
vehicles... you may well not have to. What excites me the most about making a commercial solar car
is showing to the world that we can be much more efficient with the energy that we have available,
without having to compromise on the convenience you get every day. You may be thinking - Do
we need a commercial solar car? After all, electric vehicles are more popular than ever,
with THREE MILLION sold globally in 2020. That’s roughly a 40% increase from the previous year!
Well, unfortunately, due to the lithium-ion batteries that they rely on and the electric grids
they use to recharge, turns out - these “zero emission vehicles” may not be as sustainable as
we need them to be. Another alternative is to have a solar electric vehicle that reduces a nation's
dependence on the grid, that uses the Sun, which is 90 million miles away and works every day.
So, how are these two automakers able to use solar as their car’s primary power source?
According to Arjo, it comes down to balancing a fundamental equation. Yeah, so basically
it's the amount of energy you consume per mile and the amount of energy you
generate each year from the Sun. And if you take a relatively traditional car, it's like this, so
energy consumption, energy yield. There’s a big gap. By leveraging the latest advances in solar
technology, Lightyear maximizes energy yield. And by focusing on efficiency in their car’s design
and engineering-- Step by step, you get the energy consumption down. But it’s still not
at the same level as your energy yield. So you also have to work on the other side.
Lightyear focused on three key areas: the powertrain, rolling resistance and aerodynamics.
Focus Number One: The Power Train. So there's four motors individually in each wheel,
which means there's no longer a mechanical drive shaft or a final drive. And all of
these mechanical components that of course generate friction, they add weight. You
can get rid of all of that. This lighter,
more efficient powertrain of course also reduces rolling resistance--Focus Number Two.
Lightyear One’s body and chassis are also made of lightweight materials, like aluminum and
carbon fiber allowing the five -seat, family car to tip the scales at an estimated fourteen
to fifteen hundred kilograms. Many EVs currently on the market are nearly twice as heavy. Finally,
there’s aerodynamics. Lightyear One has a drag coefficient of less than 0.2. So it's really,
really low compared to five seater production cars today on the market. Keep in mind that in
coming up with this aerodynamic design, Lightyear also had to make room for solar panels, seats and
take driver and passenger comfort into account. Not the most aerodynamic shape, not the biggest
solar panel area. So it's not the best in one category, but the balance across all of them.
Of course, Aptera faced the same design and engineering challenges.
Challenges they’ve been able to overcome thanks to the latest advances in solar technology.
One of the things thats’ changed is the efficiency of new solar cells.
And the new solar cells that are available, like the ones we use,
are so efficient, they allow us to do things now that we couldn't do 10 years ago. Like covering
nearly every meter of their car’s surface in solar cells. But Aptera also focused on efficiency. An
approach perhaps best exemplified by their car’s aerodynamic design. It's really the result of
asking, what’s the most aerodynamic shape that you could put around two people side-by-side?
And when I started thinking about building a car and how it would look, and how we designed,
this sort of epiphany of being stuck on the freeway and looking at all the
vehicles surrounding me -- trucks, and cars, and station wagons, and everything just looked like
big bricks to me. And so getting into, why are cars boxy? Why are they styled that way?
And then, why is it necessary to do something different if you really
want to make an efficient vehicle? Steve and his team came up with a radically different design,
inspired in part by the solar racers they saw in competition.
What we did is take that way of thinking as a starting point and then bring it on automotive
design and say, how do we retain the -- technical roots and the efficiencies
but yet make it a commercially viable vehicle. The result: a three-wheel, two-seater car with the
drag coefficient of zero-point-one-three, one that the Washington Post compared to the Batmobile! The
side view mirror--the square side view mirror on a Ford F-150 has about the same amount of
drag as our entire vehicle. Aptera’s solar electric vehicle also uses in-wheel motors
as well as lightweight, composite materials like carbon fiber and a type of fiberglass
called E-Glass. Composites let you put more structure, and more safe structure with less
weight and cost than steel. The sleek design, efficient powertrain, and use of lightweight
materials allows for Aptera’s base model to weigh just 800 kilograms! Compared to EVs, I mean--it's
fractional. One of the EVs we drove the other day I think weighs over 6,000 pounds.
To give you an example. I mean that's a tremendous amount of weight.
A lighter, more aerodynamic car means less energy needed to move the vehicle.
We burn about a hundred watt-hours per mile. And -- to put that in perspective,
it's-- much less than a motorcycle. So, by starting with a clean sheet of paper
and making something that's efficient from day one. And making something that's powered by the
Sun-- it felt like it was a way to differentiate ourselves from anything that's out there.
Everyone else is making electric vehicles, we're making solar electric vehicles.
The need for clean, sustainable transportation has never been more urgent. And with the
growing realization that today’s EVs may not get us to Net Zero fast enough,
maybe it’s time to explore alternative solutions to sustainable transportation. Should it be
something that harnesses the energy directly from the Sun? Should it reduce our use of the
grid? Should it give us more freedom and more autonomy? That's the direction I'd like to see
it go. So I do think that in the long term solar cars will be accessible to everyone. And that's
where our mission statement comes from: "Clean mobility for everyone everywhere". That's what
we want to achieve, and we see the solar car as the opportunity to make that happen.
For a deeper dive into solar cars, check out Light Speed: Powered by the Sun,
Seeker’s 8 chapter learning playlist on the technology behind the 2019 World Solar Challenge.