Complex sentence: Negawatts can potentially be measured in the furture with grid systems, smart meters, and other energy tracking devices; however, they currently cannot be accurately measured, only theoretically determined based on the history of consumption.
Split into simpler sentences: Negawatts can potentially be measured in the furture with grid systems, smart meters, and other energy tracking devices. However, they currently cannot be accurately measured, only theoretically determined based on the history of consumption.