Passive solar lighting, also called daylighting, uses direct or indirect sunlight to provide lighting for buildings without using electricity. It has several advantages including reducing energy costs by 13.8%, requiring no equipment or maintenance, conserving fossil fuels, and having environmental benefits as it produces no pollution. Effective daylighting is achieved through properly positioning and sizing windows to allow natural light in, and using exterior shading to diffuse sunlight. Large windows, clerestory windows, and skylights are key to passive solar daylighting.