Calculating the 25/30 year savings

The 25/30-year savings represents the estimated amount of money the customer is predicted to save by switching to solar over a 25/30 year period. 

This value is found using this equation: 

(estimated 25yr cost of staying with electric) - (estimated 25yr cost of switching to solar)  = estimated savings over 25years

These two values, "Stay with Electric" and "Switch to Solar", are represented by the bar graph in the middle of the page. 

Stay with Electric 

This is calculated by taking the current utility bill total and multiplying it by the utility escalation rate for 25/30 years. For example, if the utility escalator is 4% and the current utility bill is $45, the equation would look like this:

(45 x 1.04) + (46.8 x 1.04) + (48.67 x 1.04).... <- this would be done for each year of the 25/30 year period. 

This provides you with the average monthly bills for each year. To get the total annual cost for each year, these averages are then multiplied by 12. Then, each annual cost for all 25/30 years is added together to get the estimated 25/30 year cost of doing nothing. 

Switch to Solar

This is calculated by taking the post-solar utility bill total and multiplying it by the utility escalation rate for 25/30 years. For example, if the utility escalator is 4% and the post-solar utility bill is $45, the equation would look like this:

(45 x 1.04) + (46.8 x 1.04) + (48.67 x 1.04).... <- this would be done for each year of the 25/30 year period. 

This provides you with the average monthly bills for each year. To get the total annual cost for each year, these averages are then multiplied by 12. Then, each annual cost for all 25/30 years is added together and added to the net system cost. It is important to note that to get the new utility bill values, the system automatically calculates the escalation rate being applied before the solar system offsets the cost.