Transactive Energy Controls Survive First Test in Pacific Northwest
IEEE, July 16, 2015. Image credit: Wokandapix
The Pacific Northwest Smart Grid Demonstration project was far reaching and had more than 50 experiments, but the most cutting edge was testing transactive controls for the power grid. The project was led by Battelle and funded by the U.S. Department of Energy.
Transactive control involves an automated communication and control system connecting energy providers and users, who constantly exchange information about price and availability of power. When an energy provider predicts a surge in power demand, and therefore also higher prices, for example, it sends out this information as “transactive signals” to the rest of the network, including users. Based on these signals, smart grid technologies can react, reducing power use at the right time. The goal is improving reliability and efficiency, allowing for more dynamic balancing of resources, especially in regions that rely on high levels of renewables.
In the Pacific Northwest, wind is the dominant intermittent renewable energy. The demonstration project sent transactive signals from the grid balancing authority to many utilities in the area. The utilities could then dispatch the signals to what are known as assets (everything from electric hot water heaters in homes to grid-scale batteries) connected to the network, and these could reduce consumption temporarily to avoid the higher energy prices and, more important, they’d collectively prevent demand from outpacing supply.
Every five minutes, signals were exchanged between the participants, (called transactive nodes) on the network. For the demonstration project, the signals used simulated models of the bulk generation in the region, including hydropower, wind, and thermal power. Each node competes based on its flexibility and ability to modify its load. “With this understanding,” the study found, “the distinction of source (as generation) versus load (as energy consumption) becomes less important.”