Get ready, I'm going to poo-poo this story. Sorry for being a Debbie Downer.
I understand from one person's perspective, it doesn't seem like all that much. It's only $0.34 per person per year. Not bad, right?
Assuming the author's numbers are accurate... now take that 2.628 kilowatt hours (kWh) and multiply it by approximately 275,000,000 adults (over the age 18) in the US (source: Kids Count Data Center). (Although, I should probably include kids, because they have so many electronics nowadays.) I'm assuming all adults would have similar vampire power demand as the author.
So, now we have 722,700,000 kWh being used by chargers that are not in use. Multiply that by the author's $0.1298 per kWh, and we have a cool $94 million dollars being wasted a year. Ouch.
Not only is that money wasted, power is wasted. Power has quite the negative effect on the environment. We waste a heck of a lot more than just $0.34 a year per person. Billions of gallons of water are withdrawn EVERY DAY here in PA for power plants. Now include the rest of the US. Oof.
Not only that, other natural resources such as coal, oil, natural gas, and plutonium have to be mined and transported to the facilities. Where does all the waste go? Back into the earth as waste. Water withdrawn can impinge/entrain aquatic communities in the intake systesm. Heated wastewater has negative impacts on the aquatic community downstream of the facility.
I read a similar article from someone in California a few months ago that essentially said it was ok to leave the water running while brushing/etc, because 'so little water' is used. Yes, by one single faucet, not a lot is used. For the population as a whole, it's another story. A bad story.
I'll be the first to admit that I don't always unplug when I should, but I think articles such as this give a false impression of our impact on the environment. They pull a very tiny piece of the entire process and say its ok. We need to look from cradle to grave.. look at the process holistically.
These articles try to justify our laziness. IMO, that's not right.
End rant.