Stellas keep primarily each other sharp during EC

Eleven solar cars built by student teams took to the track during the iLumen European Solar Challenge. Setting off at 13.00 hrs on Saturday afternoon, they drove circuits of the Belgium Zolder race track for 24 hours straight. Stella Vie and Stella Era took part in the cruiser class and finished second and first - because they had no other competition. The nine other cars were all driving in the challenger class.

To be exact, Stella Vie drove 161 circuits of 4-plus kilometers in a 24-hour period. This adds up to 645 kilometers and some. In the final analysis, the latest car from Solar Team Eindhoven, Stella Era, drove another 272 kilometers.

For quite some time, Stella Vie held the lead position in the iLumen European Solar Challenge. An impressive performance, says Charlot Felderhof, technical acquisition & business innovation manager for Solar Team Eindhoven 2021. “Stella Vie, built in 2017, had been off the road for a good long while. It is no mean feat that the team got her all fixed up and roadworthy over the past few weeks. In fact, she drove more efficiently than Stella Era, which has a larger battery and performed so well at the last Bridgestone World Solar Challenge. But there came a moment when something started rattling in Stella Vie's wheel housing and she was forced to make a short stop - and this gave Stella Era the chance to finish in first place.”

24 hrs

Seventeen students from Team 2021 and twenty-one students from the two previous teams kept the cars moving for twenty-four hours. The night shift tried to nap during the day on camp beds at the camp site near the circuit and the daytime crew were able to stretch out at night. “Every hour or two, there was no set pattern, the car's occupants were switched. We had four people in the car: the driver, the co-driver and two passengers in back. I myself never took the wheel, because I'm in the new team and we are still building our car.” Whether she will drive at some later stage, Felderhof does not know. “To get the special Stella driving license, you have to be pretty strong. The car has a large turning circle and no power-assisted steering.”

Coaching from the pit box

During the race, the co-driver is in close contact with the laneteam in the pit box, and with the race stewards. “To hear what the best strategy is, what shape the batteries are in, the consumption rate and whether we'd be wise to drive a little faster or slower,” says Felderhof. “And, also, whether anything untoward is happening on the circuit.”

As was the case when the Aachen car tipped over. “It happened in the bend. That shook us up, I can tell you; we were driving right behind them. Then you have to check with those in charge whether you can safely skirt the accident site.” Things turned out alright for the German car. It was hoisted back to the workshop and was able to return to the track an hour later.


All eleven solar cars in the two classes were on the track at the same time. STE had no competition; the five other cruiser teams had cancelled due to corona. When you know from the outset that you are going to come first and second, the pressure is minimal, to say the least. “It was quite fun to battle it out between ourselves,” says Felderhof. “Because we are on friendly terms, we helped each other and could both perform well.”

Energy left over

Solar Team Eindhoven is choosing the cruiser class in preference to the challenger class because they want to develop not a single-seater racing car, but a family car. “That's more valuable to society, because it demonstrates that, like any other energy source, solar energy allows you to take to the road,” says Felderhof. This weekend STE also demonstrated that even after entering a 24-hour contest with Stella Era, you still have enough energy left over to fry up a ‘tasty bitterball or two’.

The challenger class was won by Agoria Solar Team from Belgium.

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