This online tool recommends solar PV emergency backup systems for civic and other large buildings. The goal is to replace diesel generator based emergency backup systems, increasing demand for solar PV and reducing greenhouse gas emissions. Buildings that have a solar PV backup systems can reduce their daily electricity usage because, once the backup batteries are topped off, the power generated by the solar panels goes to reduce the building’s electrical load. This tool is still in beta mode as the engineers at Arup fine tune the electrical load calculations.