PVWatts is a popular web application for estimating the energy production of a grid-connected photovoltaic (PV) system. We use this as tool when selecting PV panels, so we can ensure our clients get the top producing modules in the market. Our mission is to no only sell you modules at the lowest DC $/watt but also compare $/Kwh, since this is what utilities bill users at. Allow us to help you design your system utilizing PV watts or the other modeling programs.