How much electricity- and money- does it waste to leave the TV on? Too much!
As a young child during the energy crisis of the mid-1970's, I remember seeing distinctive stickers encouraging people to save electricity. The black sticker was sized to fit over a light switch and said "Kill-A-Watt" in bold white letters. The stickers were meant to remind people to turn out lights when leaving a room.
I must say, I learned this lesson well. I am quite good about turning off unneeded lights whether I am leaving a room or not. My son once pointed out that he knew it was me coming down the stairway at night because I turned out the lights BEFORE coming down the stairway in the dark. Who else would do that?
Tonight I was working on writing some new articles that are due in a few days. I noticed that the TV was left on in the living room and no one was watching it. I started thinking about how much energy- and money- that was wasting. I knew from looking it up in the manual that the TV draws about 300W. I also knew that the cost of electricity here is about 10 cents per kilowatt hour. That is pretty good, the average in the USA is around 12 cents per killowatt hour. If you are curious, you can find average electric rates for your state listed in this NPR article.
I figured it would take me about 15 minutes to finish the outline I was working on. Since the TV was drawing about 1/3 of a kilowatt per hour, it would cost about 3 cents to run it for an hour. This works out to about 0.75 cents if I were to leave it running 15 minutes while I finished my article outline.
But wait, there's more. Not only does it waste energy to run the TV with no one watching it, it also burns up the useful life of the TV. I could estimate the value of this by figuring out the typically lifespan of a TV. But since the TV was only about 30 feet away, I simply walked over and turned off. I pushed the "off" button by hand instead of using the remote control. Might as well save some battery life in the remote control...
In this case I didn't save much electricity by turing the TV off right away, but I did save energy worrying about it. Some people would say, why worry about wasting a few cents and a little bit of electricity. I say, why waste any at all?