How much energy is really saved by using a compost tumbler?

So how much energy are we really saving by composting with a compost tumbler Every day, the average person in the United States produces 4.6 pounds of garbage. About half of this garbage can be placed into a compost tumbler and returned to the soil. So for each person, that is about 840 pounds of compostable material per year.
With over 300 million people plus living in this country, that is 252 billion pounds of garbage that could be composted, but instead is being hauled off to landfills. I will continue next time with an estimate on how much energy that saves. But first I have to find out how much energy the actual garbage trucks use. But really think about the compost tumbler, ok?
Til next time
Hal