Studies of home price increases resulting from solar installation have been conducted in a few states, so we tend not to extrapolate that data for the whole country. Instead, we use a standard estimate for home price increases based on 20 years of free electricity at the current retail rate. It works surprisingly well to predict the kind of value bump you can see from installing solar

Here’s the formula we use to calculate expected electricity generation for 20 years:.
Below is a table that shows the results from the estimate equation, with values rounded to the nearest thousand. Not all the numbers in the chart are accurate; each depend on the state and local laws of your area. Check with your city or county assessor’s office to get the most accurate numbers.

How much money will solar save you?