Bootnote: To relieve the mind of a commentard who can't understand why a racing car would be fined for breaking the speed limit: the entire event is run on public roads, and receives its permit on the condition that contestants follow the speed limits.
As another commentard mentioned:
From the article the "race" sounds more like a "rally", where your timed over certain sections and lose time of you arrive late, but are much more heavily penalised if you arrive early to a time control/checkpoint,
So call it a solar rally then! Racing, by definition, is getting to the endpoint as fast as you can! From Wikipedia:
A sport race is a competition of speed, against an objective criterion, usually a clock or to a specific point. The competitors in a race try to complete a given task in the shortest amount of time. Typically this involves traversing some distance, but it can be any other task involving speed to reach a specific goal.