to prepare ourselves for, uh...

the situations that can happen,

because to win this race

it means taking risks.

MAN: Oh!

Oh! [BEEPING]

[THUNDER RUMBLING]

DEREK: When young engineers

join the fraternity of

a solar car team,

it's just the beginning of

an unforeseeable

yet life changing journey.

[THUNDER RUMBLING]

A commitment that

begins as a choice

[indistinct shouting]

rose into an obsession.

[indistinct shouting]

And when their ideas face

not only fierce competition,

but the reality checks

of Mother Nature,

their bond grows with the struggle.

And their will becomes

even more consumed with the desire to win.

[THUNDER RUMBLING]

[INDISTINCT CONVERSATION]

YANTE VAN HAM: That night was very... very tough.

There was a lot of wind, there was lot of sand.

There was a thunderstorm out of nowhere, lightning strikes.

[THUNDER RUMBLING]

And then in the meantime we still had to fix the car.

So, we set up a

make-shift workshop

with wooden crates and everything

and then we fixed the car in the middle of nowhere.

[INDISTINCT CONVERSATION]

It was tough but

yeah, we pushed through.

DEREK: It's challenges like these

that can either

break a team or

bring them even closer together.

DRIES KETELSLEGERS: In the middle of the night, I woke up

with a tent right in my face.

Like, everything was blown to pieces.

So, I ran out and started helping here

getting the tents back in,

getting all the stuff to the truck.

It's an adventure.

I mean, in 60 years we can

talk to our children and say,

"Ah, we've had that and sandstorms"

and everything, so...

I thought it was quite cool.

As we get into South Australia,

the wind is picking up because there are

fewer and fewer trees.

Without that coverage,

well, the winds can whip up to incredible

speeds here

and fly across the roads.

That can cause solar cars

to spin around,

lose their bearings

and maybe ruin some of their

delicate mechanics.

[INDISTINCT CONVERSATION]

DEREK: The journey in and out of the next control stop,

Coober Pedy, is a few hundred kilometers of

notoriously treacherous road

for this race.

And climate change has only made

these winds stronger

and more dangerous.

The section around Coober Pedy is very difficult,

as there is a lot of sidewinds.

And our light solar cars are very

sensitive to those sidewinds

as they get blown away

and the pilot has to constantly

work on the steering wheel to keep

the... car going straight.

[INDISTINCT CONVERSATION]

Go, let's go. Let's go.

SIDD BIKKNNAVAR: Starting of the day, we'll be fighting some

pretty high head winds

from Coober Pedy to Glendambo.

That's the next to two control stops.

The weather models are all predicting

50 kilometers power winds.

So, it drains the battery

'cause you're fighting through the wind

and the other thing is

it makes uh... steering very difficult.

Plus you have gust from side to side,

road trains, so it'll be

a really difficult day.

DEREK: In spite of the harsh conditions,

last year's champions

Vattenfall, are on the attack.

Yeah, yesterday we were

22-23 minutes behind Twente

and now we are only three minutes behind,

so, uh, we made up for a lot of the time.

And I think we'll be able to

overtake Twente today.

We've got a couple of drivers that are

really good with driving with

big winds, so we hope

they will sort this out today

and we can go as fast as we want to.

DEREK: For three days straight, Solar Team Twente

from the Netherlands, has held on to the lead.

An impressive accomplishment.

But with Vattenfall right on their tail,

things maybe about to change.

JASPER DE GROOTE: So, yesterday was kind of a hectic day.

So, like we had some issues with our solar panel

that was clapping uh... open

because of the wind but,

we fixed it overnight and made sure

it will not happen again

and I have no clue

how it will go uh... today

and how the weather will play out.

DEREK: And while two formidable Dutch teams

are still leading the pack,

team Tokai are convinced

that their bullet design

is far superior

for handling strong winds

than the catamarans out front.

Today is the day to make their move.

KOTA FUKUDA: Our design is

not for straight wind

not uh... but also

for the side wind.

So the effect is smaller

than other teams, I think.

DEREK: Using complex

fluid dynamic simulations,

Tokai designed a vehicle shaped

like a dart.

The majority of the weight

upfront, and a rear

that forms a cross.

Like a dart, their car

actually gets it more stable

the faster it goes.

Increasing stability further,

Tokai carefully shaped the shoulder of the car

to direct crosswinds, down and back.

It's an ingenious design.

Meanwhile, team Agoria has developed

a completely different solution.

VAN HAM: We also have a system built into our car

which is called crabbing.

And for crabbing we turn

the car sideways.

DEREK: By using four wheel steering,

Agoria is able to turn their car

into the wind.

And thus greatly reduce

drag and lateral force.

VAN HAM: This helps us reduce air resistance.

So, when there is a side wind,

we can tilt the car and then it

catches that side wind, and then

the aerodynamic air resistance

is reduced.

As the only competitor

from Germany, and the...

challenger class,

it's our goal to

take on the Dutch, as

we say in our team.

So we need to

show that we are able to finish the challenge