The development of electrical grids .
Lighting has been an important element in stadium design , allowing games to be played after sundown , and in covered , or partly covered stadiums that allow less natural light , but provide more shelter for the public .
Since the development of electrical grids , lighting has been an important element in stadium design , allowing games to be played after sundown , and in covered , or partly covered stadiums that allow less natural light , but provide more shelter for the public .