I have yet to see evidence that leaving an electronic device on 24/7 wears it out faster than turning it off at night. On the other hand, I haven’t seen any evidence that turning it off at night hurts it, either.
Nevertheless, I vote for turning things off whenever practical.
Leaving something on when you’re not using it wastes electricity, and electricity costs money. What’s more, if your electricity comes from burning carbon, it damages the planet we depend on. I’m not saying you should move to a cave and give up all of your gadgets (I certainly couldn’t do that), but why waste power that you don’t need?
Because Rick specifically asked about networking gear, let’s look at that. I have a router, a modem, and two network printers plugged into one surge protector. When I researched an article on vampire power earlier this year, I discovered that it would burn 12KWh over a month of absolutely no use. Without the printers, it dropped to 4.8KWh—still a lot to waste.
My wife and I now turn off that surge protector before going to bed, and turn it on in the morning, saving some power. But we couldn’t do that if our daughters were still living with us. College kids work and play late.
Computers, of course, can be put into convenient power-saving modes. But shutting them down entirely will save even more. Yes, you’ll have to wait while they boot up in the morning, but just as a good night’s sleep clears the cobwebs from your brain, a fresh boot can make Windows faster and more stable.
The peripherals around your computer (monitors, speakers, and so on) can best be controlled with a smart surge protector such as the Belkin Conserve Smart AV. Plug your PC into the surge protector’s Control outlet, and when your computer shuts down (or goes to sleep), the device cuts power to other outlets.