Recent and Planned Enhancements for PVWATTS

PVWATTS is an Internet-accessible software program that allows the user to easily calculate the energy production and cost savings for grid-connected photovoltaic (PV) systems located throughout the United States. Recent enhancements have been made to allow the user to define the system location by the use of zip code or latitude and longitude coordinates, and to receive more detailed performance information by providing a.c. energy production for each hour of the year. Future enhancements under consideration are also discussed. They include more flexibility for the user in defining system losses from soiling and in the conversion from d.c. to a.c. power, an option for international locations, and accounting for PV module shading.