Other than the obvious need for sunshine, what do solar cars and their teams have to contend with to make it down the Stuart Highway from Darwin to Adelaide?

Weather

Ideally, the sun would shine the entire 3,000km of the race, but when it doesn't, teams must be prepared to quickly change their strategy and the designs of their cars.

Cars in the Cruiser category — vehicles designed for practicality instead of just speed — are allowed to recharge by generator, but get higher efficiency scores if they can avoid that and run on solar they've stored during the day.

The speed-focused Challenger-category cars, however, are not allowed to charge at all, meaning the clouds play a bigger role — ultimately determining whether the cars stay in the race or not.

This year's event proved particularly tricky, with overcast weather plaguing teams as they approached Central Australia, forcing a number of teams to pack their cars onto trailers before the cut-off time of 5:00pm.

On overcast days, the solar arrays on Queensland's TeamArrow car gathered about 15 per cent of the power they would normally get on a bright sunny day, chief technical officer Cameron Tuesley said.

"Solar car racing is probably closer to sailing than normal motor sport," he said.

"You're very dependent on the weather, and it's not just the rain but also the wind.

"We're constantly tweaking and tuning [our strategy], so every 20 minutes or so we're coming up with new ideas on how we want to approach what we're seeing."

Threatening grey skies also made evening maintenance for the team difficult, given the workings of the car are high-voltage and potentially dangerous if exposed to water.

The University of Michigan drives its solar car during cloudy conditions in Central Australia. ( ABC News: Steven Schubert )

Harsh environment

Mr Tuesley said having a team that was flexible and responded to issues collaboratively was crucial for success on the challenge.

"You really have to work as a cohesive unit. Problems are ... the nature of the beast with this thing," he said.

He said there were often big issues, and with an experimental vehicle traveling across a very harsh environment "things go wrong all the time".

"It's how they respond. What you've really got to be able to do is not just respond quickly and dynamically but also in a multi-disciplinary way.

"It's one of the great joys of working on a project like this."

Even though the cars need the sun to function, it is a doubled-edged sword.

Inside the cars can get extremely hot, usually a few degrees above the ambient temperature outside, given air-conditioning and efficiency do not go hand in hand.

It compounds the pressure on drivers to navigate road conditions, process the efficiency information coming from the solar arrays, and communicate with their convoys.

The heat is tough on the cars, too. Day one of the race saw temperatures near 40 degrees Celsius, putting Queensland's TeamArrow's battery at serious threat of overheating.

To make matters worse, the mandatory check points — called control stops — are usually on bitumen and radiate heat back up to the car, which is especially an issue for teams arriving in the middle of the day.

Issues and breakdowns during the race can test how innovative teams can be. ( ABC News: Georgia Hitch )

Breakdowns

The weather might be out of teams' control, but their design, construction, and engineering can also throw up problems.

Despite the fact all cars have to be deemed road and race ready before the challenge begins, nothing can simulate the unexpected emergencies that inevitably happen.

That could be anything from broken suspension, steering troubles, or communication and technology issues.

For TeamArrow, a tyre puncture just down the road from the Devils Marbles cost them half an hour in repairs.

"It was the rear right wheel, which is probably the most difficult to change because we don't have a spare that we can put straight in," mechanical team lead Richard Cummack said.

"But on the motor wheel, we only have two of them and the car needs both, so we have to remove the wheel and put a new tyre straight onto that.

"We were a bit disappointed [it was that wheel] because it's a pain in the ass, but it's alright."

The TeamArrow car gets an emergency repair after a tyre puncture. ( ABC News: Georgia Hitch )

Bush repairs

But issues and breakdowns also act as an opportunity to test how innovative the teams can be in the bid to find a solution.

In TeamArrow's case, the tyranny of distance between the solar car and their trailer with the tools was solved using a can of deodorant and a lighter.

"We need a method of getting a huge amount of air into the tyre in a short amount of time to get the tyre to sink into the rim," Mr Cummack said.

"If you just pump air into the tyre, it'll just leak continuously, so you have to get a big shot of air into it to let it seal.

"Normally we have a compressed air can to do that, but it was in the trailer.

"We ended up using a can of deodorant and a little gas torch to make a small explosion."

Mr Cummack said it was one of the odder fixes he had performed.

"It's pretty strange, we have to be creative; it's 3,000km and you can't be prepared for every situation you get into," he said.

"So there are often some bush fixes that happen; I think that one takes the cake though, so far."

Traffic and other obstacles

A road train can leave solar vehicles zig-zagging across the road. ( ABC News: Georgia Hitch )

Anyone who has ever driven on the Stuart Highway will know one of the biggest — and arguably scariest — things on the road is a road train.

For solar cars, especially Challenger cars that are built for maximum aerodynamics, the vacuum left in the wake of a road train can destabilise the car and send it zig-zagging across the road.

But in addition to megaliths of the highway, grey nomads, and other vehicles, Solar Challenge traffic brings its own difficulties.

Flanking every solar car are at least two cars — one in front (the lead), and one behind (the chase) — as well as a number of other support and media cars or, in one case, a media bus.

Some teams even have their own trucks to help get them and materials from one end to the other.

Driving close to and overtaking the convoys requires a specific process that can be tricky at times.

There's also native wildlife to contend with, especially near unfenced and pastoral areas.

Support team

At the end of the day, the solar car wouldn't get anywhere if it wasn't for the team of people making sure it, and all the other people involved in its working, get to Adelaide in one piece.

Support teams are responsible for keeping people fed and hydrated. ( ABC News: Georgia Hitch )

As well as the electrical, mechanical and software teams, there's also a camp team who's responsibility is to keep people hydrated, fed and — ultimately — sane.

Mike Stone is the camp leader and said he got plenty of strange looks at the grocery store before leaving Darwin.

"I reckon it was over a tonne of food that we bought in Darwin, probably about $2,500 just in food for five days," he said.

Mike Stone said he got strange looks at a Darwin grocery store when buying provisions for the race. ( ABC News: Georgia Hitch )

"We're burning though 100 litres every dinner and evening, so every camp stop is 100 litres of water at least, maybe 125.

"Milk, we go through about five litres per breakfast, bacon about three kilos, eggs about four dozen."

Mr Stone describes it as a full-time job. The camp team are the first to get up and the last to go to bed, all to make sure those working on the car have enough fuel of their own.

"If we're going to work this hard we're going to eat like kings and queens, it's the only way to do it," he said.

"It's no good to put a team like this, working this hard for this long and do it on effectively Weetbix and Vegemite; it's not going to work."

And so the team is treated to entree, main and dessert, a little slice of luxury on otherwise long and taxing days.