Indoor Solar Cells

Scientists in China and Sweden have developed a commercially viable organic solar cell designed to generate power using indoor lighting. Although the technology is only applicable for low power applications, it is ideal for powering the Internet of Things when used in temperature sensors, security sensors and other low power electronic devices.

By carefully determining the composition of the active layer materials, efficiencies as high as 26 percent at ambient lighting levels of 1000 lux (typical of that found in a supermarket) have been achieved. At levels of 200 lux (normal living room illumination), that translates to an operating voltage of 1.8 volts at 45 microamps. And when used in conjunction with small supercapacitors, devices could remain powered even in the dark.

The new Organic PhotoVoltaic (OPV) cells are inexpensive and sustainable to manufacture since they don’t rely on scarce or toxic materials. They can be produced in thin, flexible sheets that are easily integrated into a variety of product designs. In addition, recent testing has indicated that polymer-based OPVs rival silicon in terms of efficiency, with a life expectancy of 20 years. Future applications will include using them in buildings to supplement traditional solar power as well as large-scale energy production.