Italian Solar Challenge Results

Above are official lap counts (in two stints) for the recent Italian Solar Challenge at the Imola Circuit near Bologna.

Bochum reported electrical problems with their SunRiser, and did not race, although they had successfully completed a qualifying lap (both Bochum cars had driven all the way to Italy). The local Italian team had even more serious electrical problems.

According to the regulations, for the Challenger class, there should be added to the scores above:

  • 2 laps for the fastest lap during the race (Aachen gets this, with a time of 4:09.236 in the first stint, i.e. 70.9 km/h for the lap)
  • 4 laps for the pole position in the qualifications (Aachen gets this too)

Consequently, Aachen’s lap score should, I understand, be adjusted up to 95.

Update: it seems that the organisers have decided to retroactively merge the two classes. Rankings are therefore:

  1. Aachen
  2. Bochum
  3. Solaris
  4. Solis-EV

Italian Solar Challenge now on

The Italian Solar Challenge is now on at the Imola Circuit near Bologna. A calendar for the event is shown above. Further details and team social media links can be found on my annotated teams list. See also the race social media at    

The Covestro Sonnenwagen (left) and the thyssenkrupp SunRiser (right) are 2 of the 7 cars at the event (photos by Anthony Dekker, click images to zoom)


The start grid is shown below, courtest of team Sonnenwagen Aachen, who also have a livestream here. It seems that I was wrong in the pictures above; Aachen are racing only the three-wheel Covestro Photon. Bochum reports electrical problems with their SunRiser, which they expect to race only a few laps.

European Solar Challenge: Further Analysis

I updated my previous post to include visualisations of the official results of the iLumen European Solar Challenge. However, a helpful commenter shared a link to the detailed lap data, so above and below is some further analysis on lap times. Colours are the same as in the previous charts. As always, click to zoom.

The chart at the top shows pit time (including recharging time) as almost-horizontal lines, and pit time is also visible as gaps in the chart below. The histograms show that Top Dutch (6), the two cars from Sonnenwagen Aachen (7 and 70), Istanbul Technical University (34), and the experienced drivers in BOSolarCar e.V. (11) were particularly good at driving consistent lap times.

Measured by median lap times, Stella Vita from Eindhoven (41), Covestro Photon from Aachen (7), SunRiser from Bochum (11), RED E from Twente (42), and BluePoint from Agoria (8) were the fastest cars.

European Solar Challenge Lap Data

All too soon, the 24-hour iLumen European Solar Challenge is over. The charts above and below (click to zoom) show results from the live timing board. The winners of the two classes (Challenger and CR = Cruiser) will be decided on points scores, which are still to come. Meanwhile, however, the German teams from Aachen and Bochum deserve special congratulations. For updates, see also the race social media at    

Update 1: there are apparently no official results yet. All that has been released has been the podiums:

  • Challenger: 1. Covestro Photon (Aachen), 2. Covestro Sonnenwagen (Aachen), 3. RED E (Twente)
  • Cruiser: 1. Lodz, 2. Onda Solare, 3. Stella Era (Eindhoven)

Using the guidelines in the official regulations, I can calculate the Challenger class scores (see below).

Update 2: the official results have now been released, and I have added the chart below. Bochum seems to have lost out from having a two-seater car. For the rest, practicality judging makes up 40% of the final Cruiser score at iESC, so that Lodz essentially won on practicality (although I note that four of the Cruisers raced in Australia in 2019, and I would have expected both practicality and efficiency scores at Zolder to have been somewhat similar).

Italian Solar Challenge 2022

Following the iLumen European Solar Challenge in Belgium will be the Italian Solar Challenge, from 25 to 30 September at the Autodromo Enzo e Dino Ferrari near Bologna. Here is a list of 5 teams from 4 countries (3 Challenger teams and 2 Cruiser teams) intending to race in this event. See also the race social media at    

The ISC permits up to 6 m2 solar panels in both Challenger and Cruiser classes. Detailed regulations can be found on the ISC website.

IT  Onda Solare 

Four-seat cruiser (Emilia 4 LT) – they won the American Solar Challenge (Cruiser class) in 2018, and they have written up their design process here, but they have since made substantial improvements to the vehicle, including to the aerodynamics, suspension, battery, and solar panels. There is also an unusual open tail.

Previously, Onda came 10th at WSC 13; participated in the WSC 19 Cruiser class; won the ASC 18 Cruiser class; came 10th at Abu Dhabi 15; came 6th at iESC 16; won the iESC 21 Cruiser class; and came 2nd in the iESC 22 Cruiser class. Their team number (9) is taken from the SS 9, the highway through Bologna, which was once the Roman Via Aemilia (hence also the name of their vehicle).

Left: credit / Right: credit (click images to zoom)

11  DE  BoSolarCar Association (BOSolarCar e.V.) 

Two-seat cruiser (thyssenkrupp SunRiser) – BOSolarCar e.V. is an association of Bochum alumni that maintains and races old Bochum cars. They will also race their older SolarWorld GT in Italy.

Previously, Bochum came 2nd in the WSC 13 Cruiser class; came 3rd in the WSC 15 Cruiser class; came 2nd in the WSC 17 Cruiser class; came 4th in the WSC 19 Cruiser class; came 3rd, 4th, and 5th at iESC 16; came 2nd, 3rd, and 5th in the iESC 18 Cruiser class; came 3rd and 4th in the iESC 21 Cruiser class; came 4th in the iESC 22 Cruiser class; came 1st and 7th at Albi Eco 18; came 1st and 2nd at Albi Eco 19; and came 3rd at Albi Eco 22.

Left: SolarLabor / Right: Anthony Dekker (click images to zoom)

70  DE  Sonnenwagen Aachen 

Three-wheel (outrigger) challenger (Covestro Photon) – their older monohull, Covestro Sonnenwagen, will also be on track in Belgium.

Previously, Aachen participated at WSC 17; came 6th at WSC 19; came 3rd at iESC 18; came 5th and 8th at iESC 20; came 2nd and 6th at iESC 21; came 1st and 2nd at iESC 22; and came 5th at SCM 21. Their team number (70) is the number they raced with in 2017.

Left: Anthony Dekker / Right: credit (click images to zoom)

81  TR  Solar Team Solaris (Dokuz Eylül University) 

Challenger (S11) – they have replaced their old catamaran with a bullet car, which they will be racing again.

Previously, Solaris participated in the WSC 13 Adventure class; came 25th at WSC 15; came 18th at WSC 19; came 9th at iESC 16; came 7th at iESC 21; came equal 8th at iESC 22; came 2nd at Albi Eco 18; and came 2nd at MSRC 19.

Left: credit / Right: credit (click images to zoom)

99  RO  Solis-EV (TU Cluj-Napoca) 

Challenger (Solis) – this is team is from Cluj-Napoca in Romania.

Previously, Solis-EV came 9th at iESC 21 and came equal 8th at iESC 22.

Left: credit / Right: credit (click images to zoom)

This page last updated 08:45 on 26 September 2022 AEST.

European Solar Challenge results

The iLumen European Solar Challenge is over. Challenger Class results are shown above, and Cruiser Class results below. The heights of the bars show points allocated in the various categories. Twente was third overall on points in the Challenger Class, although a very close second in terms of laps (344).

A number of teams had some unfortunate problems, and the Cruisers from Eindhoven and PUT Solar Dynamics were not able to hit the track at all. For pictures, see team social media (see my list of teams) or iESC social media at        (click on the icons).

Update: see also this lap chart.

The Cannonball Sun

Something a little different in the solar car space today. Will Jones and Kyle Samluk are mechanical engineering students from two different universities in Michigan, with a background in a high school team. Eschewing the mainstream competitions (as many major teams are doing), they have built their own solar car, and between 22 June and 6 July they are planning to drive it the 4,900 km or so of the Cannonball Run from New York to Los Angeles.

The US has been crossed in a solar car before (in 2012), when Bochum’s SolarWorld GT made its round-the-world trip. It clocked up a scenic 6,553 km in just over 50 days, from San Francisco via Dallas to Charleston, SC, requiring frequent charging stops and additional solar panels in the trunk. Will and Kyle, assisted by fellow-student Danny Ezzo, hope to cross the US in less than a third of the time. You can follow their progress on their website and on Instagram or Facebook. They are also raising funds needed for the trip.

Top L: Pink Skies with aerobody but no solar panels, Top R: Pink Skies with solar panels but no aerobody, Bottom L: chassis, showing tadpole wheel configuration, Bottom R: rear (driven) wheel [images from the Pink Skies team].

The chassis of their car Pink Skies is a monocoque made from sheet aluminium, with bulkheads riveted in (it looks more like an Abrams tank than an aircraft, to be honest). The solar panels appear to be originally intended for rooftop use. They make up about a third of the weight, but produce a substantial 2.2 kW of power (roughly double that of a typical ASC or BWSC car).

For energy storage, Will and Kyle have taken the safer LiFePO4 option. The suspension is pretty much missing in action, so the ride is likely to be somewhat bumpy. Top speed appears to be an impressive 110 kph, with a 70 kph cruising speed. Will and Kyle also seem to have done a good job of engineering on-the-fly as testing revealed problems with the initial design. I salute their initiative and their vision and I wish them well as they drive across the American continent.

Solar Racing Basics: Chassis

Click to zoom / Image credit: American Solar Challenge

Continuing the analysis of my Solar Racing Basics Poster (see this tag), solar cars have to keep their driver safe and the vehicle in one piece. There are two basic ways of doing this. First, a car can have a carbon-fibre-reinforced polymer body over a metal chassis. For example, Bochum’s thyssenkrupp blue.cruiser (below) is supported by a tubular frame of ultrahigh-strength steel. Second, a car can have a load-bearing “monocoque” body, possibly also of carbon-fibre-reinforced polymer. Carbon-fibre-reinforced polymer is strong for its weight, and this is significant, since a noticeable amount of energy in a solar car (though less than aerodynamic drag) is lost in rolling resistance. The rolling resistance of a car is proportional to its weight (it also depends on the quality of the tires), and so reducing weight makes the car faster. In 2019, the lightest solar car (from Western Sydney) weighed just 116.8 kg without the driver.

Cars may include a “roll bar” or “roll cage” to protect the driver in addition to the monocoque body. This “roll bar” or “roll cage” may be made of metal tubes, or it may also be made of carbon-fibre-reinforced polymer. A close look at unpainted carbon-fibre-reinforced polymer shows the “chequerboard” pattern of carbon-fibre “cloth” embedded inside transparent epoxy polymer (as in the body and roll bar of Durham’s Ortus, also below).

Click to zoom / Image credits: Anthony Dekker (Bochum’s thyssenkrupp blue.cruiser and the interior of Durham’s Ortus)

To read more, see see this post about car body and chassis by Nick Elderfield of the University of Calgary Solar Car Team, this Instagram post about composite materials by MIT Solar Electric Vehicle Team, and this UMNSVP wiki on Composite Chassis Design.

Solar Buggy aftermovie!

Credit (click image to zoom)

Hochschule Bochum is famous for their Cruiser-class solar vehicles. But they also have a solar buggy team   ). In 2019, they attempted a world record for crossing the Simpson Desert. Things did not go entirely according to plan, thanks to unusually high temperatures and strong winds, but they certainly produced a fantastic, innovative vehicle.

A few days ago, they released a spectacular 100-minute aftermovie of their world record attempt (see the 3-minute teaser and the full aftermovie). Well worth a look!

European Solar Challenge: update #3

Below (click to zoom) is my latest guess at the field of cars for the 24-hour iLumen European Solar Challenge to be held at Circuit Zolder in Belgium on 18–20 September (Durham has, sadly, withdrawn from the event). All car photographs except the Swiss one are mine (taken at WSC). See this page for team details and further iESC information.

In other sad news, we might see some rain during the race. One a more positive note, most teams have been getting in some driver practice.

Below are some pictures from recent social media of five teams (use the picture above to identify teams):

Breaking news: in a sad turn of events, Bochum are out of the Cruiser class, as are Lodz. This leaves only Eindhoven in the Cruiser class. See the current teams list here.