DESIGN GOALS AND CHALLENGES FOR A PHOTOVOLTAIC-POWERED ELECTROCHROMICWINDOW COVERING

As the technical issues of performance and durability of electrochromi c (EC) windows near resolution, more attention is being focused upon t he economics of ''smart'' window fabrication, installation and operati on. A retrofit EC window covering that could be readily applied to exi sting windows could have several economical advantages, particularly i f it were photovoltaic (PV)-powered. Such a window covering could be p roduced on a flexible polymer substrate that would be adhered to the i nside surface of a window. It could be conveniently replaced as newer, better coverings were developed and would not have to have as long a proven service lifetime as would a permanent window coating. A PV-EC w indow covering could also obviate the need for expensive electrical wi ring for power and controls. Along with the advantages of a self-power ed ''smart'' window covering come disadvantages and new technological challenges. In this paper, we will describe the design options and cha llenges associated with this retrofit concept which are presently bein g studied at NREL.