When light bulbs are operating we only care about the energy coming off as light but about 95% of the electrical energy put into a standard bulb is turned into heat instead. Something similar happens to solar panels as they can only absorb a certain fraction of the sun’s radiation limiting their efficiency. Scientists, however, have managed to tailor the thermal emission spectrum of certain materials so that they can be used to improve efficiency in various scenarios. By heating a tungsten filament to 3000K and surrounding it with a cold infrared interference system designed to reflect infrared radiation but allow visible light to pass through meant that the scientists created a light source with energy efficiency of 40%. They intend to continue their research and hopefully overtime they will be able to get this system to surpass the current efficiency of commercial fluorescent bulbs and also apply this research in the field of thermophotovoltaic energy conversion.