The Residential Electric Rate Analysis Tool utilizes Green Button interval data, the location of the home, and solar design factors (azimuth, tilt) specific to the home to show how the addition of a solar electric system will affect a residential utility customer’s bill. Once the analysis is complete, the residential utility customer will have a deeper understanding of how various solar systems sizes will affect their monthly and annual utility bill.
Step 1: Enter Details
Use the compass on the map above to determine your home's azimuth. For example below, the house on the left has an azimuth of 180, while the house on the right has an azimuth of 225.
The slope is a ratio based on the rise of the roof compared to the run. The rise is a vertical measurement and the run is a horizontal measurement of 12". Using the roof slop table below, we see that a roof with a 7:12 ratio has a slope of 30.26°. Measure your roof's tilt now and enter it into the field above.
Step 2: Upload Green Button File
Many electric service providers (utilities) have provided access to your Green Button Data through their online customer portals. Green Button Data is a downloadable XML file that contains your home's energy use information. Visit your utility's website and sign in to access your account. From there, locate the link to download your Green Button Data (look for the following icon):
A separate login/registration is often required to access your Green Button Data. Once you've accessed your Green Button Data, download and save the XML file to your computer. Click the browse button below to upload the file from your computer. Once you've completed that, proceed to step 3.
Step 3: Enter Solar System Size (kW)
Enter the size of the solar system you plan to install. If you are unsure, enter 4. Toggle the up and down arrows to adjust the size and see the change reflected in the charts below.
Annual Energy Bill Before Solar (Tiered): $
Annual Energy Bill After Solar Installation (Tiered): $