How to increase the capacity of the Electric Grid with new technology

Getting new transmission lines planned, approved, and constructed is a daunting task, often taking a decade or longer to complete. So, how can the world more quickly add transmission capacity to the system without investing enormous time and money in the process? The answer: grid enhancing technologies, or GETs.

“GETs are exciting to us because they are technologies that help us unlock quickly the additional headroom or additional capability of the grid to carry energy across the system,” Alexina Jackson, vice president of Strategic Development with AES Corp., said as a guest on The POWER Podcast . “This is something that is very important, because today, we are not making the fullest use of the electricity system as it’s built.”

The system is operated below its maximum capacity for very good reasons, specifically, to maintain reliability, but by implementing GETs, it can be operated closer to its true limits without risk of failure. “Once we have these technologies, such as dynamic line rating, which helps us visualize the dynamic and full headroom of the electrical grid, and then technologies like storage as transmission, advanced power flow control, topology optimization—they all allow us to operate the grid in its dynamic capability. By doing both these things—visualization and operation dynamically—we’re able to start making fuller use of that carrying capacity for energy, which will allow us to add additional energy more quickly, serve our customer needs more efficiently, and ultimately decarbonize faster,” Jackson said.

AES published a white paper in April titled “Smarter use of the dynamic grid: Accessing transmission headroom through GETs deployment.” The 20-page document goes into much greater detail on the four items Jackson mentioned—dynamic line rating (DLR), storage as transmission (SAT), advanced power flow control (APFC), and topology optimization.

DLR. The paper explains: “Traditionally, TOs [transmission owners] use static or seasonal line ratings based on worst-case assumptions—for example, the hottest time and day of the season under low wind speeds. This often results in conservative ratings that do not accurately reflect the true thermal capacity of a line at a given point in time. In contrast, DLR provides real-time visibility into line capacity and customized rating profiles on lines that are otherwise identical.”

SAT. Again, the white paper explains: “In operations, Storage as Transmission (SAT) can absorb excess generation during periods of low load and store it near load to dispatch during peak periods when transmission lines risk congestion. Using storage in this way reduces system costs from congestion pricing and can reduce harmful pollutants and overall carbon emissions by avoiding use of peaking thermal power plants.”

APFC. Advanced power flow control (APFC) controls the magnitude of power flows along specific transmission paths, and can mitigate thermal and stability issues that arise by changing the flow to alternative paths, the white paper says. Without getting too technical, Jackson explained that APFC alters the impedance on lines to encourage flow via a desired route.

Topology Optimization. The AES white paper explains: “Topology optimization refers to the strategic reconfiguration of the power grid’s structure by switching the status of circuit breakers, switches, or other controllable devices. This process involves switching transmission lines in or out and/or splitting bus sections. For example, if load is growing rapidly and stressing one feeder, grid operators can transfer all or part of the load to adjacent feeders through switching actions at substations and minimize the risk of equipment failure and outages. Studied topology optimization solutions can be applied quickly to mitigate unexpected events like equipment failures or demand changes.”

To hear the full interview with Jackson, which contains more about the benefits of GETs and some of AES’s projects, listen to The POWER Podcast .