How much energy do we use vs do we waste?

I always hear how coal plants are 30 % efficient. That is really low but doubt it will change much. We need to do is help out our own gas and electric bill . I've said this before, as a carpenter I see houses that are so wasteful it makes me mad. 6" of insul in attics is quite common, 3" is common too way up here in Wisconsin. I can't tell some owners nothing neither. They, like many on this thread hear building owners say 3-5 years is too long of pay back. I wait a few days and ask " how long ya own this home"? Ah, 25 years! Go figure. I have been slow on work the last few months and told everyone in our house if there is a light on turn the #$%%^% thing off. My electric bill went from 85 avr. to 65 last month, (@.16 a kwh). Never did anything else. Next step is the few last storms windows, then insulate the top basement walls. A storm on the front door too. I built this house 3 yrs ago with the idea of the very most efficient house possible. Still have a bit to do, but some day.