Negawatt power is energy that is not used. It comes from making changes that help us use less energy, like turning off lights when you leave a room. For example, if a house normally uses 100 watts of electricity and then they make changes to use only 90 watts of electricity, they have created a "Negawatt" of energy because they didn't use 10 watts. It's like if you had a candy bar and only ate 9 pieces instead of 10. You still have the same candy bar, but there is one less piece of candy. Negawatts work the same way - you still have the same amount of energy, but you are using less of it.