To restart the grid after a blackout, grid operators must first turn on a conventional energy source, like a coal or natural gas plant, before they can add other energy sources, like solar and energy storage, to the grid. In the newly published Research Roadmap on Grid-Forming Inverters, researchers from National Laboratories, universities, and the U.S. Department of Energy (DOE) Solar Energy Technologies Office (SETO) outline a plan to use renewable energy to jump-start the grid by taking advantage of an essential piece of connection equipment known as an inverter.
Inverters provide the interface between the grid and energy sources like solar panels, wind turbines, and energy storage. When there is a large disturbance or outage on the grid, conventional inverters will shut off power to these energy sources and wait for a signal from the rest of the grid that the disturbance has settled and it is safe to restart—known as “grid-following.” As wind and solar account for increasing shares of the overall electricity supply, it is becoming impractical to depend on the rest of the grid to manage disturbances. Grid-forming inverters are an emerging technology that allows solar and other inverter-based energy sources to restart the grid independently.
The new roadmap highlights recent innovations in grid-forming inverter technology. It identifies the challenges for researchers and operators of the small isolated grids or microgrids where this technology could be piloted. In the short term, research opportunities exist for creating new grid-forming hardware, software, and controls, redesigning regulatory and technical standards, and developing advanced modeling techniques. Building on these, the authors envision a future where grid-forming inverters are integrated into electric grids of steadily increasing size and complexity over the next 10–30 years.
The roadmap was developed through a SunShot National Laboratory Multiyear Partnership (SuNLaMP) project with broad collaboration among scientists, DOE staff, and key industry stakeholders. Other SETO-funded research under the FY2019 Funding Program and FY19–21 Lab Call, as well as DOE-wide efforts like the Grid Modernization Initiative, also informed the roadmap. The roadmap authors represent a wide array of institutions: National Renewable Energy Laboratory, Lawrence Berkeley National Laboratory, Sandia National Laboratories, University of Washington, and the University of Wisconsin.
As the rapid deployment of renewable technologies transforms the electric power system, it is critical to maintain the grid’s reliability and stability. The roadmap is intended to serve as a key milestone for long-term grid modernization efforts that enable grid operators to integrate more solar, wind, and battery storage resources.