Abstract: A photoluminescent dye is suspended in a transparent medium. When exposed to light, the dye re-emits light in a narrow frequency range. Photovoltaic cells responsive to the re-emitted light are arranged around the sides of the collector medium, and are electrically connected to a low power demand device, such as a calculator. A reflective surface is placed next to the collector medium and kept a slight distance away such that an air gap is formed between the collector and the reflective surface. This gap increases the efficiency of the collector to the point that the collector will operate a small calculator even though exposed to low light levels such as are normal in an office environment.