She said the regulation limiting the surface area of the cells negated most of the advantage they provided.

CNN: Michigan solar car team wins 2,400-mile race

While the ozone layer in the upper atmosphere plays an important role in limiting harmful ultraviolet light reaching the Earth's surface, low-level ozone is a pollutant that is harmful, causing respiratory problems in animals as well as well-documented cases in humans.

BBC: Invasive plant 'increases ozone pollution'