America’s increasing reliance on intermittent power sources and batteries is creating novel risks, according to grid specialists who testified before Congress on July 18. Many of the greatest among them emanate from a key geopolitical rival, China. That’s partly because the new technologies frequently use inverters. When solar panels, wind turbines, and battery systems generate or store direct current electricity, inverters turn it into the alternating current electricity that flows through the grid. Paul N. Stockton, a senior fellow…