Indoor Solar to Power the Internet of Things

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In today’s age of smart technology, our houses are full of smart devices- from smart Wi-Fi-connected home security systems to smart toilets, the Internet of Things is everywhere, and it needs electrical cords or batteries to power it. Now, researchers are bringing solar panel technology indoors to power these devices and show which photovoltaic (PV) systems work best under cool white LED lighting that is now popular inside the house.

The mission of indoor solar power is tricky due to the vast differences between indoor lighting and sunlight- not only are light bulbs dimmer than the sun, sunlight also includes ultraviolet, infrared, and visible light, whereas indoor lights typically shine light from a narrower region of the spectrum. The solar panels created to harness power from sunlight are not optimized for converting indoor light into electrical energy.

Although some next-generation PV materials (including perovskite minerals and organic films) were tested with indoor light, it is still not clear which are the most efficient at converting non-natural light into electricity.

Unlike other studies that used various types of indoor lights to test PVs made from different materials, the researchers compared a range of different PV technologies under the same type of indoor lighting. According to Techxplore, the researchers obtained eight types of PV devices and measured each material’s ability to convert light into electricity, first under simulated sunlight and then under a cool white LED light.

Gallium indium phosphide PV cells had the greatest efficiency under indoor light, converting nearly 40% of the light energy into electricity, while a material called crystalline silicon demonstrated the best efficiency under sunlight but was average under indoor light.

Although Gallium indium phosphide has not yet been used in commercially available PV cells, this study points to its potential beyond solar power. However, the researchers add that gallium-containing materials are expensive and may not serve as a viable mass product to power smart home systems.

Interestingly, the researchers discovered during the study that part of the indoor light energy produced heat instead of electricity—information that will help optimize future PVs to power indoor devices.

This information was provided by Techxplore.