From Conor Friedersdorf”s Atlantic piece about energy-saving motion sensors, now widely used in Spain:

“In the vast majority of tapas bars and restaurants I patronized, and in train stations and other public places too, I’d open bathroom doors to find it dark inside, start to fumble for a light switch, and remember that practically every last light is now triggered by motion sensors, a cheap alternative to the status quo here: leaving the lights on all the time, whether anyone is in the bathroom or not.

The motion sensor was also put to use in at least one shopping mall that I visited in Valencia. With four or five stories of stores, it had a bunch of escalators to transport shoppers from one level to another. Instead of running them at full speed all the time, however, they slowed down considerably when no one was on the steps. Tripping an invisible beam while walking onto the bottom step, it sped up immediately to normal escalator speed, costing patrons no time and saving energy.”