Advanced Flexible Solar Array

Achieving a high specific power value for solar arrays is critical for military and commercial spacecraft, especially considering the trend toward small spacecraft with the same or increased power requirements. During the Air Force/Phillips Laboratory Lightweight Solar Array (LWSA) project, it was established that a 100 W/kg solar array can be achieved by integrating an 8-percent efficient single junction thin film Copper-Indium-Gallium-Diselinide (CIGS) photovoltaic cells into a lightweight picture frame type structure. ITN Energy Systems is proposing an ultra-lightweight concept for an advanced, flexible solar array system that can provide a specific power of 200 W/kg or greater. The key technologies which enable the proposed concepts are:1. The development of a high efficiency (>20 percent) multi-junction photovoltaic cell on a thin flexible substrate.2. A unique lightweight pantographic support structure.The increase in specific power of the PV module is achieved through development of multijunction PV cells employing CIGS, CIS and CdTe absorber layers. Through appropriate choice of absorber bandgaps, multijunction cells can achieve higher conversion efficiency than is possible with single junction devices.