WSC: three gem awards

Nuna9, the car from Nuon Solar Team

It has been my tradition to hand out “Gem Awards” after major solar car races. This WSC, the “Faster Than Lightning” gem again goes to Nuon Solar Team, the undefeated Challenger champions.

The 2017 “Faster Than Lightning” gem goes to Nuon Solar Team


Stella Vie, the car from Solar Team Eindhoven

The “Solar Family Car” gem again goes to Solar Team Eindhoven. They completely dominated the Cruiser class.

The 2017 “Solar Family Car” gem goes to Solar Team Eindhoven


Western Sydney Solar Team

The “Solar Car Family” gems go to Western Sydney Solar Team, for the way that they welcomed international teams passing through Sydney. Western Sydney Solar Team are, of course, also Australian champions in the Challenger class.

The 2017 “Solar Car Family” gems go to Western Sydney Solar Team


WSC: South to the border

The afternoon of race day 3, and several teams have been struggling. In the Cruisers, Singapore and Sunswift were forced to trailer. On the other hand, Nuon is streaking ahead to the South Australian border, and Michigan might be breaking the “curse of third.”

The map above (click to zoom) shows GPS positions extrapolated using GPS time lag and the average speed since the start of the race (i.e. it’s a best guess for the true position of the car at the indicated time). Adventure-class teams are not shown. The table below shows team numbers, raw road distance from Darwin, average speed, extrapolated road distance, class (or number of seats for Cruiser class), team name, team social media links, and links to pictures or status reports. For a live map of raw GPS data, see the official tracker.

3 1757.5 km 80.7 kph 1758.4 km C Nuon  photo
2 1682.8 km 77.4 kph 1685.5 km C Michigan 
21 1667 km 76.6 kph 1668.9 km C Twente  video
10 1656.1 km 76.1 kph 1657.2 km C Tokai 
8 1626.7 km 74.8 kph 1629.6 km C Punch  photo
11 1493.6 km 67.1 kph 1493.7 km 4 Bochum 
88 1487.2 km 66.9 kph 1489.9 km C Kogakuin  photo
15 1487.1 km 66.8 kph 1487.7 km C WSU  photo
42 1485.8 km 66.8 kph 1485.8 km A TAFE SA  Adventure
40 1473.8 km 66.3 kph 1476.5 km 5 Eindhoven 
28 1435.3 km 64.5 kph 1435.3 km A KNUT  Adventure
30 1429.8 km 64.3 kph 1432.5 km 2 Arrow 
35 1430.4 km 64.2 kph 1431.3 km 2 HK IVE 
75 1394.7 km 62.8 kph 1394.7 km A Sunswift  Adventure
94 1394.3 km 62.6 kph 1394.3 km 2 Minnesota  video
95 1359.8 km 61.4 kph 1367.4 km 2 Apollo 
4 1364.4 km 61.3 kph 1365.5 km C Antakari 
5 1364.2 km 61.3 kph 1364.2 km A Singapore  Adventure
16 1352.2 km 60.7 kph 1352.9 km C Stanford 
77 1345 km 60.4 kph 1345.6 km C Blue Sky 
43 1320.9 km 59.4 kph 1320.9 km A ANU  Adventure
25 1317 km 59.2 kph 1317.9 km C Nagoya 
46 1294.8 km 58.2 kph 1296.1 km C JU 
38 1263.4 km 56.7 kph 1264 km C NWU 
70 1262.5 km 56.7 kph 1263.6 km C Aachen  video
32 1251.6 km 56.2 kph 1253 km C Principia 
53 1228.9 km 55.2 kph 1228.9 km A Choctaw  – Adventure
71 1210.3 km 53.4 kph 1210.3 km C ITU 
22 1210.3 km 54.1 kph 1210.3 km A MDH  Adventure
82 1169 km 51.3 kph 1169.3 km C KUST 
20 1168.2 km 51.3 kph 1168.2 km A Durham  Adventure
9 1160.4 km 51 kph 1161.2 km 4 PrISUm 
49 1147.6 km 50.4 kph 1147.6 km A Siam Tech  Adventure
45 1145.9 km 50.3 kph 1146.2 km 5 Lodz 
52 1126.3 km 49.5 kph 1126.3 km A Illini  Adventure
37 1124.5 km 49.4 kph 1125.3 km C Goko 
18 1118.2 km 49.2 kph 1118.2 km A EcoPhoton  Adventure
7 1069.7 km 47 kph 1069.7 km A Adelaide  Adventure

Bochum heading into Alice

World Solar Challenge: Challenger dimensions

MostDece has written a superb blog post on the WSC challengers. Based on that, I’ve updated my previous post on dimensions. The infographic above (click to zoom) shows the reported length and width of 16 WSC cars (Challenger class only, this time). The widest car (at 2.05 m) is the South African car from NWU (below), but of course that includes the outrigger wheels. The narrowest is the long narrow bullet car from Michigan. There are also short zippy little cars from Nuon, Principia, and Punch.

Update: The chart below clusters cars with similar length/width combinations. NWU is a visible outlier. Below NWU, we have big cars (ITU, MDH, Adelaide, Aaachen, JU – over 1.6 m wide and at least 4 m long), short catamarans (Nuon, Principia, Punch – 1.55 to 1.6 m wide and at most 3.5 m long), narrow catamarans (Nagoya, Stanford, Twente, WSU – 1.38 to 1.5 m wide and at least 4 m long), and monohulls (Tokai, Kogakuin, Michigan – at most 1.2 m wide and over 4.9 m long):

Update: Unfortunately, the two charts above reflect incorrect information from the Stanford team. The Stanford car is actually substantially wider.

World Solar Challenge: solar cells

Part of the rule changes for the 2017 World Solar Challenge was a change to allowable solar cell array areas. In the Challenger class, the limits became 4 m2 for silicon and 2.64 m2 for multijunction gallium arsenide (in the Cruiser class, 5 m2 and 3.3 m2, which is the same ratio). Depending on the efficiencies of the two technologies, we therefore get the following comparison:

There are two important caveats, however. First, the cars in the World Solar Challenge will be getting pretty hot. The performance of multijunction GaAs degrades less with heat than that of silicon, so this increases the benefit for GaAs beyond that shown in the chart. For example, if we assume a 24%/35% efficiency combination for Si/GaAs, with temperature coefficients of power of 0.4%/0.2%, then the red dots in the chart show a GaAs advantage above about 43°C.

Secondly, the use of a 2.64 m2 GaAs array allows teams to build a smaller (and hence more aerodynamic) car, as Nuon and Punch have done. This increases the benefit for GaAs even further. Consequently, the five favourites (Nuon, Twente, Tokai, Michigan, and Punch) are all capable of winning the race, but the teams that switched to GaAs might have made a good move.

Update – the graph below clarifies the temperature-dependence for the two technologies (assuming a 24%/35% efficiency combination for Si/GaAs, and temperature coefficients of power of 0.4%/0.2%):

World Solar Challenge: the favourites

I will need to re-do this at some point, but the poster below shows the favourites (based purely on 2015 performance) for the 2017 World Solar Challenge (click to zoom). There is a very interesting mix of designs this year! For more details, see my annotated list of teams.

World Solar Challenge: teams beginning to arrive

Teams are beginning to arrive in Australia for the 2017 World Solar Challenge. Scrutineering begins in 30 days!

Instagram memories from Eindhoven, Bochum, Nuon, Twente, Nuon, and Michigan.

World Solar Challenge: doing media right

I’ve often pointed out that a solar car team is more like a startup company than anything else. A little like the early days of Google, really. The main product (the solar car, the search engine) is a gigantic money sink, and any cash coming in relates to something else (sponsorship, advertising). Overall success requires multiple skill sets working together. In particular, making sponsorship work requires an excellent media team (as well as a car fast enough to generate lots of good news). A number of teams have a track record of doing this well – Twente, for example, and Punch.

Deufol Technics packs Punch’s car and gear yesterday

An important example of sponsorship relates to transport. Here, the team acts as a kind of giant billboard for a tricky logistics problem handled well. This year, Punch provided a textbook example of superb media handling on this topic:

‘Voor mij is het de eerste keer dat ik voor zo een uitdaging sta,’ zegt logistiek manager Pieter Galle uit Leuven. ‘Het batterijpakket versturen is de grootste uitdaging voor het team. De batterijcellen die wij gebruiken zijn vaak niet toegelaten op vluchten. Om deze toch te kunnen versturen moeten er veel veiligheidsmaatregelen getroffen worden. Gelukkig heeft DHL Global Forwarding, in samenwerking met Deufol als verpakker van de goederen en batterijen alles tot in de puntjes kunnen regelen, zodat wij ons met het team volledig op het wereldkampioenschap konden concentreren.’” (Translation: “‘It’s the first time I’ve faced a challenge like this,’ says logistics manager Pieter Galle from Leuven. ‘Transporting the battery pack was the biggest challenge for the team. The batteries we use are often forbidden on flights. To be able to send them, many safety measures need to be taken. Fortunately, DHL Global Forwarding, in cooperation with Deufol our packer, has managed all the details, making it possible for us to focus our attention on the world championship.’”)

And Pieter Galle wasn’t just engaged in hyperbole there – transporting lithium battery packs really is tricky. In 2015, and again this year, there have been horror stories involving battery packs. I should also point out that some good photos really help the sponsorship game too, like these from Twente this year, or this one from Michigan, or this one from Nuon in 2015:

Nuon’s 2015 flightcase being loaded (photo: Jorrit Lousberg)

Another important sponsorship category relates to the team’s university. Here Western Sydney provides an excellent example, with their 2015 car being part of a major university rebranding exercise:

Western Sydney University’s 2015 car (photo: A. Dekker)

Michigan always does a great job of this during the American Solar Challenge. Their media team generates local news coverage everywhere they go. And the University of Michigan can afford to take the long view. If a 12-year-old boy or girl somewhere in rural America gets excited by the car, and decides to study engineering at Michigan one day, that’s a win. And not just for the university – if the sponsorship money keeps rolling in, the cars keep rolling on, and the fans can keep watching.