..."This year's edition of the biennial race marks 30 years since it was first held in 1987 to showcase the emerging power of solar energy."...
The speed has increased a bit....
..."The first edition of the World Solar Challenge was run in 1987 when the winning entry, GM's Sunraycer won with an average speed of 67 km/h (42 mph).[6]Ford Australia's "Sunchaser" came in second. The "Solar Resource", which came in 7th overall, was first in the Private Entry category.[7] "...