The increasing incorporation of renewable energy sources into energy grids boosts the environmental sustainability of electric power delivery but increases the complexity of system management for operators. A new tool devised by the U.S. National Renewable Energy Laboratory (NREL) is intended to help grid operators and equipment manufacturers adjust to this energy transition.

The Grid Impedance Scan Tool (GIST) enables the identification and prevention of potentially disruptive electrical oscillations. Grid reliability is improved in systems that feature such diverse components as wind and solar energy generators, batteries, electric vehicle stations and new grid hardware.

GIST software uses digital models of the entire electrical system and its components to measure the impedance, or electrical resistance, of devices at their point of grid interconnection to evaluate system stability. These software-only scans are augmented by evaluations of hardware such as battery storage on-site at the lab. The tool effectively identifies the devices and controls causing electrical oscillations and other instability problems under certain operating conditions, enabling implementation of remedial solutions.

NREL and GE have partnered in using GIST to demonstrate the ability of the company's Type III wind turbines to run in grid-forming mode, where the generating facility could set grid voltage and frequency and operate without power from the electric grid if needed.

Available for licensing from NREL, the software is compatible with any renewable energy device and can prevent early mistakes in project planning.