Welcome to the new PVWatts. What's new?
The latest minor release in October 2016 changed our source for India rupee exchange rates and a few bug fixes.
PVWatts® was updated on July 2016. Capacity Factor has been added to the displayed results page and both the monthly and hourly downloads.
Our previous release as in April and it removed available incentives from the app. Our source of incentives was found not to be consistent enough to provide an accurate reflection of costs. If a consistently up-to-date source of incentives becomes available, we will add it back into the system.
We are often asked about the annual variation in what the system will produce and how different the actual results will be.
We analyzed 30 years of historical solar irradiance and weather patterns for 239 locations in the US. The historical data was used to estimate PV system production ranges for two prototypical system configurations and create charts to show how your annual results may vary in a nearby location.
The calculated results from PVWatts® are an estimate of what you might actually experience, and are based on assumptions, uncertainties, and incomplete information about your particular PV system and location. The new internanual variability information provides ranges for possible energy generation in different years, and be useful in deciding whether to install a PV system.
We hope you enjoy using this latest version of PVWatts!
The NREL PVWatts Team.