For work, I use a laptop connected to a bigger computer monitor, but I rarely use both screens. So I was curious how much energy is saved by turning off the laptop display when not in use. My laptop LCD screen is not an LED model which I assume is even more frugal on the watts, so your mileage might vary, but FWIW, it seems like the difference for me is ~10W-11W.
Times 50 weeks of 8 hour on-time (as an estimate) that is 20KWh (10W * 50*5days*8hrs) and to put that into perspective from a “visualize energy” standpoint, that is almost as much as we make on an average day from our entire 6.9KW PV array. It’s also $4/year assuming 20cents/KWh.