How does the load levelling strategy differ from the load shifting strategy in thermal storage?

The load levelling strategy involves storing energy during off-peak hours and releasing it during peak hours to reduce peak demand and flatten the load profile. The load shifting strategy, on the other hand, involves shifting the entire load from one time period to another, typically from peak to off-peak hours. Load shifting can be used to take advantage of time-of-use (TOU) pricing structures, where energy costs vary depending on the time of day.