Integrated Photovoltaic Energy Scavenging and Storage System

The majority of modern portable, wireless electrical devices are powered by batteries; when the batteries are depleted they must be replaced or recharged, which is a problem when the system operates in remote areas or an enemy's region. The capability to scavenge energy from the environment to recharge batteries and/or directly power electronics is essential to increase system lifetime and utility. Solar radiation is the most abundant and highest power source for scavenging, but is completely absent at night. Consequently, alternative power system designs are needed which supplement solar based scavengers with complementary techniques minimizing impact on system size and weight. Aurora proposes to develop an integrated energy scavenging and storage system which utilizes: 1) triple junction solar cells for highly efficient solar energy scavenging, 2) advanced infrared photovoltaics for night time thermal energy scavenging, and 3) thin film lithium cell technology to produce a power dense storage system. These component technologies will be stacked in a layered fashion and integrated with the system structure to provide additional weight savings and footprint reduction. The proposed system has the capability to produce as much as 30 mW/cm2 from incident solar radiation and convert thermal radiation at efficiencies as high as 3%.