Sun-tracking Photovoltaic Arrays (IMAGE) Washington University in St. Louis Caption During the cold winter months the Living Learning Center at Washington University in St. Louis drew enough energy to throw its annual energy budget into the red. To reach zero net energy, the WUSTL team had to add sun-tracking photovoltaic arrays to supplement the generation capacity of arrays installed on the building's roof. Credit WUSTL Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.