Various states in the US have either adopted, or are in the process of adopting, IEEE 1547-2018, which leverages new capabilities of smart inverters. Smart inverters are a kind of “grid-following” inverters. Now there is growing interest in “grid-forming” inverters, which are not new but are relatively early in the technology development and application standardization life-cycle.

The great promise of grid-forming inverters is that they will be able to serve the same purpose as synchronous machines, and allow very high penetrations of inverter-based resources (think 100%), such as solar, wind, and battery energy storage, and still have a stable, secure bulk power system. They will accomplish this in concert with coordinated control systems in the grid.

We are still many years away from large-scale implementation of grid-forming inverters, but they got a major boost in research and development with the start of the UNIFI Consortium (Universal Interoperability for Grid-Forming Inverters) in late 2021. More info is available from NREL, which will lead over 40 organization in the 5-year effort that received $25 million from DOE and another $10 million in partner cost-sharing.