Graycor Construction Company recently completed a rooftop photovoltaic (PV) solar system on a new Walgreen's store in Evanston, Ill.. SoCore Energy, the nation's leader in solar portfolio development, called upon Graycor's solar experience to install over 800 solar panels and supporting work on this 14,112 square foot rooftop solar project.
The Evanston Walgreens is believed to be the country's first "Net Zero" energy retail store. This "Net Zero" energy prototype building also includes other alternative energy features including two 35-foot high wind turbines and a system of 550-foot deep geothermal wells for reducing the building's heating and cooling loads. In order to offset the higher construction costs for the project excess site-generated energy, including solar power, will be used by the building or sold to local utilities. To make this possible, the DC power generated by the 225-kilowatt photovoltaic system first needed to be converted to AC power. This was accomplished through the use of Graycor-installed rack-mounted micro-inverters, which feeds power from the PV panels into the local utility system via an electric panel and meter located in the building's main electrical room.
During construction, the team had to deal with a few obstacles in order to complete this unique solar project. Steve Crowley, Senior Project Manager at Graycor Construction states, "A major challenge on this project was that the rooftop system had to be installed during the construction of the building shell, with panel installation starting while the roof decking work was still in progress. This required close coordination with the shell building GC, and roofing and electrical subs for work space access, deliveries and safety." In addition to the coordination challenges, the multiple tiers of standing seam metal roofs, all slightly sloped, were not typical for rooftop PV installation and required the construction team to modify installation procedures.
Graycor was proud to partner with SoCore Energy and Walgreens on this project as it provided a great opportunity to showcase each player's alternative energy expertise. Along with the environmental contributions from projects such as these, Graycor also believes that the educational impact is important, so hearing that college engineering professors and international tour groups have expressed interest in visiting the new Walgreen's store to learn about the state-of-the-art features has been very encouraging news. In addition to this solar project, Graycor recently completed a 250-kilowatt rooftop solar installation project for Cedars-Sinai Medical Center in Los Angeles, CA. Matt Gray, Co-chairman of Graycor states "Sustainability has grown to become a key component on more and more construction projects today. We are proud to have been involved with this innovative project and are thrilled to be seeing an emergence of new opportunities for solar technology and environmentally sensitive buildings throughout North America."