How one device could help transform our power grid

From Colorado to Washington, from Ohio to Pennsylvania, coal-fired power plants are shutting down. The United States is on track to retire half of its capacity to generate electricity from coal by 2026. That’s a remarkably fast decline from coal’s peak in 2011 — and a major step in the shift to clean energy and the fight against climate change.

But there’s a surprising downside to retiring big, old power plants. These plants help maintain the power grid’s stability. As more of them go offline, something else must step up to do that job.

An electrical grid is a complex network involving systems that produce power, like a nuclear power plant or a wind turbine, and systems that store and transmit power, like batteries and transmission lines. A grid can stop functioning for any number of reasons, such as a tree falling on a power line or a heat wave overwhelming the system’s capacity. In the United States, electricity pulses through the grid like a heartbeat at a standard frequency of 60 hertz. That frequency can shift if demand increases beyond supply…