The Solar Sign IPRO started in the Spring semester of 1997. The purpose of the sign is to promote solar energy and other clean energy technologies by projecting daily messages. The sign is visible to commuters on heavily traveled Chicago highway and visitors to Comiskey Park, home of the Chicago White Sox. The project has been conducted in two phases.
Solar energy is seasonal, varied and intermittent.
Therefore, energy storage, conversion and delivery to satisfy application loads are key system design criteria for specific PV applications. The solar panels were received as a matchable gift from Solarex Corporation. A pyranometer measures the daily insolation and shunt resistances within the array current. Over a given time the array voltage and current are acquired as a function of insolation. The array current integrated over a period of time gives the amount of charge that is available for charging the battery packs.