These transparent, electricity-generating coatings have the potential of turning new and existing tall buildings into ‘clean power generators.’ When applied to a 50-story building, for example, SolarWindow™ could reduce electricity costs by up to 50 percent per year and achieve a one-year financial payback, according to independently-validated modeling.
Since commercial buildings consume almost 40% of all the electricity generated in the US, electricity-generating windows that reduce electricity costs could be compelling for building owners, while simultaneously providing environmental benefits and reducing carbon dioxide emissions.
In order to determine the ability of the electricity-generating coatings to withstand real-world environmental conditions, the company, along with scientists and engineers at the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL), subjected SolarWindow™ modules to cycles of high temperatures followed by extremely low temperatures to simulate natural environmental conditions.
During this test, SolarWindow™ modules were subjected to more than 200 freeze/thaw cycles, which yielded favorable performance results of the edge sealing processes and minimal impact on the device electrical performance.
SolarWindow™ modules are being designed for durability using a variety of processes and materials, including encapsulation and edge seals, to protect the layers making up the electricity-generating coating.
“This particular test is very important to establish the thermal and mechanical stability of SolarWindow™ coatings. As a part of windows of the future, such coatings will naturally be exposed to temperature extremes and cycles that cause mechanical stresses, which can eventually lead to failure,” said Dr. Scott Hammond, Principal Scientist of SolarWindow.
“By appropriately engineering our layer lamination and edge sealing processes, we can minimize such stresses and ensure long operational lifetimes, regardless of the outdoor environment the windows are exposed to.”
“Passing the freeze/thaw temperature cycle testing is another important step towards commercializing SolarWindow™ coatings,” said John Conklin, President and CEO of SolarWindow. “Successful completion of this test puts SolarWindow™ modules one step closer to meeting performance PV test standards required by IEC.”
IEC, or the International Electrotechnical Committee, defines PV performance as a set of specific test sequences, conditions, and requirements for the design qualification of a PV module. The company will address the appropriate IEC PV module performance standards when SolarWindow™ products are commercially fabricated.
“It is important to verify applicable PV and window performance standards, and confirm that our test results meet the standards. The success of the freeze/thaw temperature cycle testing, at this stage, is a positive indication of progress towards commercialization,” said Conklin.
SolarWindow™ products are being developed in collaboration with NREL under a Cooperative Research and Development Agreement (CRADA). The primary development goal of the CRADA is the commercialization of SolarWindow™ products.