The next generation of lighting is based on LEDs. They run on direct current, not alternating current like what comes into your house from the power grid.

Whether or not you can see it, if you plug your LED lighting unit into a regular power socket, a device in the unit has to convert the electricity from alternating current to direct current. Your computer has the same need for direct current. Notebook PCs and netbooks typically have a power adapter as small box in the middle of the cord you use to plug them into a power source. If it isn’t visible, it’s hidden inside the case of the device.

Like your computer, if you don’t switch off the power adapter at the outlet, your LED lamp will stay on standby and sip electricity when the lamp is off. I have switchable outlets and extension cords with a separate switch for each outlet in them, which I highly recommend. For floor lamps or for desk lamps where I would have to reach down to pull the plug or flip a switch, I prefer a switch I can step on instead. To save you from needing to hunt for one, here is the USA version of the kind I use.