No, sensor lights are designed to be energy-efficient. They use very little electricity when they are in standby mode or not activated because their sensors are not actively detecting motion or changes in light. When motion or a change in light is detected, the sensor activates the light, and it uses more electricity during that time. However, since sensor lights are typically used for short periods, such as when you enter a room or approach an area, they can actually help reduce overall electricity consumption by ensuring that lights are only on when needed, making them an energy-efficient choice.