A research team has created a thermoelectric material with promising performance at room temperature. Ytterbium silicide is a good electrical conductor. It also has a high Seebeck coefficient thanks to Kondo resonance (fluctuation of f-electrons), which increases its power factor. Its layered structure further promotes the thermoelectric effect by blocking heat conduction. This non-toxic, room-temperature thermoelectric material is competitive with conventional bismuth telluride, and could be used for power generation or refrigeration.