Our lives are ruled by things that need plugging in and charging. And they all eat up electricity, but not as much as you might think. Check out this slideshow to see how much your devices cost per year to run. Turns out that your iPad takes just $10 per year to power, even if you run the battery down and recharge it every day. A Tesla electric car ¬†stays charged for only $450 a year. And a fridge is a few hundred dollars if you have an energy-efficient one made after 2001. This isn’t license to leave the lights on or take 2-hour showers. But it’s important to understand that some things cost more to run, and others aren’t a big deal. The biggest part of your (or your landlord’s) utility bill is heating, not your latest iDevice.