Extreme voltage fluctuations, caused by electrical faults resulting in a drop in voltage, have the capacity to take down large sections of the power grid. The Grid Friendly Appliance Controller, developed by Pacific Northwest National Laboratory, Richland, Wash., operates within household appliances to reduce stress on the grid by automatically modifying power usage on the fly.

Originally designed to detect frequency fluctuations, the Grid Friendly Appliance (GFA) Controller project received an investment from Battelle to reduce its size greatly and to respond dynamically to voltage changes. During a pilot program using Whirlpool appliances, a majority of users did not detect its operation. Used in a dryer, for example, the GFA Controller turns off the heat during fluctuation but keeps the dryer tumbling to facilitate resumption of normal operation.

As a result, the power grid is able to use the load as a resource to help manage the grid by matching supply and demand, and is an especially useful tool during near-blackout situations.