Timer

A timer is used to automatically turn on or off outdoor or indoor lights based on user settings. There are 2 main types of timers - manual timers that plug into an outlet and programmable timers, that often have a digital screen.

When considering a timer for outdoor lighting, make sure you take into consideration the seasonal variation in the length of night. Look for a combination unit which may also contain a photosensor to turn them off during the daytime or a unit which allows input of latitude and longitude (astronomical clock).

Making it easy to turn equipment on and off at appropriate times, whether you are around and awake or not, can save energy if the equipment would have been on longer without the timer. One example is outdoor holiday lights, which can switch off automatically instead of staying on all night and/or all day. An even better example is the block heater for a car, in a very cold climate. These are less common now, but if you do need to pre-warm your car with a block heater, having it on a timer so that it only starts warming up a little while before you need it, can save significant energy.

Timing can be everything. During large football (i.e. soccer) matches in England, the national electricity grid can experience spikes of more than 2000 megawatts in electricity demand at half-time, as millions of people who are watching the game on TV get up off the couch at the same time and go boil some water for tea. If half those people had a timer to make the kettle come on ten minutes before half-time, the peak demand would be much smaller and easier to manage.