Graycor completed a rooftop photovoltaic (PV) solar system on a new Walgreen’s store in Evanston, Illinois. SoCore Energy, the nation’s leader in solar portfolio development, selected Graycor to install over 800 solar panels and provide support work on this 14,112 square foot rooftop solar project.

The Evanston Walgreens was the country’s first “Net Zero” energy retail store at the time of completion. This “Net Zero” energy prototype building includes alternative energy features such as 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, solar power is 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 overcame several obstacles in order to complete this unique solar project. 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.
Walgreens New Zero Engergy Store is LEED Platinum certified.