This book investigates electrical power consumptions and wastages in auditoriums/halls, offices, classrooms, and laboratories. It identifies one major source of electrical energy wastage; lightings and air-conditions/fans in the auditoriums/halls and laboratories remaining on in the absence of students, technicians, technologists and lecturers or other personnel. The system designed in this book turns on lightings and air-conditions/fans within the section in the auditorium/hall where there are persons while lightings and air-conditions/fans in other areas remain turned off.