The utility rate escalator is the assumed increase of the utility rate a customer is charged from one year to the next. The utility rate escalator is used to estimate the customer utility bill year by year.

The 25-year lifetime savings is estimated based on the difference between the estimated bill payments over 25 years, the financing payments over 25 years, and any incentives. The utility rate escalator makes a big difference on the estimated bill payments over 25 years, so can have a large impact on the total estimated savings.

Here is where the utility rate escalator and directly impacted estimates are shown:

"The cost of doing nothing" utility bill page

The assumptions page

Sighten has default utility rate escalators for different states, based on historic averages. The defaults can be updated by users with admin permissions. Utility rate escalators can be updated for a state or for a specific utility. 

See more here:

•  How do I change the utility rate escalator?
• Default rates are attached