Blackout curtain panels are a necessity for privacy. Being awoken by the sun is actually good for you, but there are times when darkening a room aids in sleep especially for napping children, shift workers or others with non traditional sleep schedules and for blocking artificial night time light such as from a streetlamp. Blackout curtains also are energy saving (keeping heat from escaping in the winter and the hot sun from heating up your room in the summer) and help block or muffle outdoor noise.