The estimable Will Ronco has risen to the challenge, telling me how much energy is contained in my 66 Butterfinger bars left over from Halloween:

I’ve got some preliminary info about those candy bars (you didn’t think i’d let a challenge like that pass unanswered did you?)
anyway, given the 17,820 kcals in your remaining candy bars, you could boil almost 59 gallons of room temperature water:

17820*1000=17,820,000 calories = 17,820,000 cubic centimeters of water whose temperature can be raised one degree

or

room temperature=20 degrees c

boiling pt.=100 degrees c

delta=80 degrees

17,820,000 / 80 = 222,750 cubic centimeters of water whose temperature can be raised 80 degrees

222,750 cc / 3785 cc per gallon = 58.8 gallons

Will’s sister Amy Smith developed a Phase-Change Incubator that developing countries can use to perform temperature-controlled water tests without any electric equipment at all. So Will’s family is obviously the authority on how to harness this wasted power.