The solar cell converts solar energy to the electrical energy which is stored in the battery. The solar lamp draws the current from this battery and it requires no other wiring. you have street lights throughout the night because it’s dark throughout the night. solar street lights include reduced dependence on conventional energy, conservation of energy and less reliance on the national grid. In countries experiencing abundance of sunlight, solar lights are the best option to illuminate the streets, garden, parks and other public spaces.