The obvious drawback of solar panels is that they require sunlight to generate electricity. Some have observed that for a device on Earth facing space, which has a frigid temperature, the chilling outflow of energy from the device can be harvested using the same kind of optoelectronic physics we have used to harness solar energy. New work, in a recent issue of Applied Physics Letters, looks to provide a potential path to generating electricity like solar cells but that can power electronics at night.