Scalable single point power extraction for compact mobile and stand-alone solar harvesting power sources based on fully printed organic photovoltaic modules and efficient high voltage DC/DC conversion

Patterns for fully printed polymer solar cells are presented that inherently enable scaling of the power output with single point electrical energy connection is presented. Connection is made to only one end of the printed foil that can be rolled out for light energy harvesting. The power level is simply increased/decreased by increasing/decreasing the length of the foil with a corresponding increase/decrease in operating voltage. The current flow runs in both directions along the printed foil thus alleviating the need for post process addition of complex busbar topologies. The power conversion takes place in a HVDC-DC converter that is tailored specifically for operation with polymer solar cells by regulation on the input side. The system charges a lithium-polymer battery thus enabling storage of 82 Wh for a printed OPV foil measuring 0.305 m x 9 m having a nominal power output of at least 15 W (AM1.5G, 1000 W m(-2)). As a demonstration we present a scalable fully integrated and compact power unit for mobile applications comprising solar energy harvesting OPV modules, power conversion and storage. Applications possible include electrical charging of mobile devices, illumination using LED lamps and low mechanical power applications such as pumping water. (C) 2015 Elsevier B.V. All rights reserved.