Running trains and electricity costs?

[nachoman]

More info:

My MRC power pack says an output of 16 VA (or 16W). That is the output, and I can only estimate how much power it actually draws from the wall. Remembering physics class, I assume it will draw more than the rated output from the wall, as some power will be lost as heat (the power pack gets warm). If I assume a relatively conservative 75% efficiency of the electronics and transformer, that equates to about 22W total from the wall, or rounded up to about 25W, or 0.025 kilowatts. Now, let's say I ran trains for 3 hours per day, for the entire 30 day month - 90 hours total. Multiply the 90 hours by 0.025kW, and you get 2.25 kilowatt-hours. I pay about 11 cents per kilowatt hour (including all kinds of environmental fees), so running my trains for 3 hours per day costs a whopping 25 cents for an entire month (2.25 x 11 cents).

For comparison, my refrigerator uses about 480 kW-h per year, or about 40 kW-h per month. The monthly cost at 11 cents per kW-h is about $4.40.