Emerging software technologies upgrade the ability to detect and react to grid issues faster and with finer detail. Maintaining a reliable flow of electricity requires matching supply and demand down to a narrow bandwidth. ISO control centers take a pulse of the power grid every four seconds to balance system needs. Most electrons are consumed the instant they are created. Not enough or too many megawatts on the grid can compromise electricity reliability. ISO operators manage this dynamic and delicate balancing act invisibly and on behalf of consumers who expect instant light at the flip of a switch. For about 100 years, not much changed in the way electricity was generated and delivered. Recently, times are changing.