To date, large fossil-fuel power plants have maintained the stability of the United States power grid in times of power fluctuations and outages. But, as the country endeavors to switch to more sustainable forms of energy, it is estimated that half of the total electricity from coal-fired power plants will be eliminated by 2026, only to be replaced by renewable sources like wind and solar power, which are not as consistently reliable and subject to volatile weather events. 

A new solution is needed to keep the power grid humming during this transition. While inverters have traditionally been used in micro-grids and small electric power systems to facilitate the interface between the power production or power storage equipment and the grid, the challenge is to scale them for large power grids that incorporate renewable energy. The U.S. Department of Energy is funding a $25 million grid-forming inverter effort. The initial focus is on setting technical specifications for the equipment and testing inverters from different manufacturers for performance and the ability to work together.