This paper summarizes efforts at the National Renewable Energy Laboratory to develop self-powered electrochromic window coatings that could be used for economical retrofit to existing building windows. The self-power is provided in either of two ways in separate approaches to the electrochromic (EC) design: by very thin, nearly transparent a-silicon PV cells or by dye-sensitized titania half-cells built into the multi-layer structure of the window coating. The goal of both designs is the ability to incorporate the self-powered EC coating into a laminated flexible polymer film. This film could then be retrofitted to a building window by bonding it to the interior surface and attaching it to local electronic controls that also derive their power from the windows that they control. Laboratory-scale prototype self-powered EC window coatings have been fabricated using both approaches. These are described and the remaining development challenges are discussed.

Date Published: 8 October 1999
PDF: 10 pages
Proc. SPIE 3788, Switchable Materials and Flat Panel Displays, (8 October 1999); doi: 10.1117/12.365773

Published in SPIE Proceedings Vol. 3788:
Switchable Materials and Flat Panel Displays
Carl M. Lampert, Editor(s)