The charts above and below (click to zoom) show the dimensions of some of the Challenger-class cars in the World Solar Challenge coming up this October (see also my illustrated teams list). In the chart above, ⬤ = cars with silicon arrays (4 m2 allowed), ⬛ = thin film single junction (3.56 m2 allowed), and ▲ = multijunction gallium arsenide (2.64 m2 allowed). All three technologies are in use this year. Hollow symbols denote cars from 2017.

Particularly noticeable is Twente’s incredibly shrinking car. They switched technologies this year, but were also so efficient that their new car is about 18% smaller than Delft’s – almost a square metre smaller! There are also three visible clusters – larger silicon-array cars at the top right, compact catamarans (like Twente and Delft) at the left, and monohulls at the bottom right. In the chart below, solid lines show dimensions for this year, and dotted lines those of 2017.

Update: the width of Eclipse’s entry has been corrected (the impact attenuator has been removed for WSC).