How to use the PVWatts Annual Calculation Needed from the PVWattsTM Grid
Data Calculator--Version 2
Use the below link to navigate to the PVWattsTM Grid Data Calculator--Version 2:
http://www.nrel.gov/rredc/pvwatts/grid.html
The above link will direct you to The "National Renewable Energy Laboratory (NREL)" site,
which is where data for the PVWattsTM Grid Data Calculator--Version 2 is located.
1. To the left of the screen, click on the link, "Launch Viewer".
2. The "PVWatts Viewer" page appears. In the pop-up box to the right, titled "PVWatts
Tool":
 Type in the Zip Code 48226 in the "Zip Code" box
NOTE: Use Zip Code 48226 for all PV System Projects
 Click "Go"
The "PVWatts Tool" box refreshes with several links (boxes):
3. Click on the second box titled "Send to PVWatts"
The next page that appears is the "PVWattsTM Grid Data Calculator (Version 2)".
Use the calculator to obtain the required data for the annual calculation information needed.
4. Under "PV System Specifications" fill in each field as it pertains to the PV system:
 DC Rating (kW)
 DO NOT FILL IN THE "DC to AC Derate Factor” field. The "DC to AC Derate
Factor" field stays fixed.
 Array Type
 Array Tilt (degrees)
 Array Azimuth (degrees)
 Energy Cost per kWh:
NOTE: If you know the cost of your electricity for your respective Rate Code, fill
in the field under "Energy Data" titled "Cost of Electricity". If you do not know the
cost of your electricity for your respective PV System’s rate code, leave the field
(number) as it appears.
5. Click the “Calculate” button
The next page that appears is the page that is to be printed and submitted to meet the PVWatts
Annual Solar Production form requirement.
6. Before printing the page, in the “Comments” box, type in the Customer Name and the
site address for the PV System installation.
7. Print page and submit along with other required documents (see Process Checklist, Step
5) within 40 business days of notification of project selection.