At Energy-Minded U.S. Hotels, They’ll Turn the Lights Off for You | nytimes.com

At the Palazzo Navona, a boutique hotel named for the famous piazza here, guests must place a room key into a slot on the wall to activate the lights and temperature control system in their rooms. The Palazzo’s use of the key card device is not unusual in Europe or in other parts of the world, like Asia. Even in countries like Norway where electricity is relatively inexpensive, many hotels use them to reduce energy costs.