What do you do when a major winter storm or a bolt of lightning has left you without power and the temperature in your home begins to plummet? Even if your back-up generator kicks in, you worry about the potential for fire and toxic fumes. Researchers are developing a sodium-based battery as an alternative power source to lithium-ion batteries that, when produced on a large scale, might one day make generators obsolete. Learn more at NSF’s “The Discovery Files.”