How much are you spending on electric for your computers?

You think it's not much. My old laptop is 65W. Recently I bought a new low end PC because it has the features I like (anti-glare screen) and four Celeron threads instead of two Core 2 Duo. The new one is pristine used, about .5 years old (though you can still buy them new) and was about $60.

so if my new laptop is 45W and the old one was 65W, and it runs 15 hours per day 325 days per year (pretty accurate), and a kilowatt costs me 18 cents (aggregate cost of generation and distribution and overhead), how much money does my new laptop save?

I did the calculations, and it didn't sound right, but AI came up with the same number:

Difference in power consumption: 65W−45W=20W
Operating hours per year: 15 hours/day×325 days/year=4875 hours/year
Power saving per year: 20W×4875 hours/year=97500 watt-hours/year
Convert watt-hours to kilowatt-hours: 97500 watt-hours/year=97.5 kilowatt-hours/year
Cost of electricity per year: 97.5 kilowatt-hours/year×$0.18/kWh=$17.55/year

So in a little over 3 years, the new low wattage computer will pay for itself.

Addendum:
It might even save more. The old one runs hot in warm weather, and it has a fan that runs all the time. The new one has a 6W CPU and there is no fan. I was just pulling the 45W and 65W off the power supply ratings. And the old one spins a hard drive, the new one static storage.