ELECTRIC-POWER grids are often categorized as the world’s largest machines, but they are not the most sophisticated. Grid operators have little data on how weather, shifting electricity consumption, and other factors affect power flows minute to minute over the grids’ high-voltage main lines. So to be safe, utilities cap the power a line carries at well below its physical limits—a drawback, given rising electricity demands. To increase capacity, grids need more smarts, and that’s what Christian Rehtanz gave them, at Zürich, Switzerland-based ABB. Rehtanz devised algorithms that use information from sensors distributed around the grid to monitor a power line—or several lines in a transmission corridor—and calculate in real time how much power it can safely carry. He then led a team that turned these algorithms into a commercial monitoring, protection, and control system for utilities, dubbed PSGuard. Norwegian utility Statnet is already testing Rehtanz’s hardware and software on a massive high-voltage corridor to Sweden, and Rehtanz predicts Statnet will be pushing 10 percent more megawatts by year’s end— potentially enough to supply electricity to an additional 100,000 homes. Rehtanz has since powered up, too; he now leads technology development for ABB’s 8,000-person global power systems business.