I've seen some pretty bad linkbait headlines related to this... so i'll defer to someone who's already done the math on how 'bad' this actually is:
A GTX 760 (170w) for 8 hours per day would consume 496.4kWh/y. At 5 hours per day (more reasonable) it would consume 310kWh/y, still higher than Xbox One, not counting ANY other forms of power consumption from the PC.
Breaking down the consumption for Xbox One: If we assume they estimated 8 hours of full consumption usage, using it to watch TV, with 16 hours of off time.. let's math! 289kWh/y = 791.8 watts per day. It consumes 15w per hour of time in standby, so 15w * 16 hours = 240w, leaving us with 551.8 watts per day while on, watching TV. Divide that across 8 hours, and you get 68.97w of power draw, comparable to an incandescent light bulb. Drawing peak power at 1/3 of an entire day. That's about $180 in electricity costs over 5 whole years. Perspective: A modest sized top-freezer refrigerator 5-10 years old will cost about $120 per year to run, or $600 over the same time period. Mind you, my math could be a little off based on how much on/off time was used to calculate, but it's a solid rough estimate.