Kevin Gorham, EPRI
Bill Meehan, Esri
Now that we have got your attention. What is a Panglossian illusion? The term Panglossian originates from Voltaire’s satire Candide, in which the character, Pangloss, is always overly optimistic. So, the phrase, when applied to the grid, would suggest that complete decarbonization of the electric supply system by 2050 may be overly ambitious.
A recent study by the DOE’s NREL predicts over 1500 GW of solar energy, nearly 1000 GW of wind energy, and almost 2000 GW of storage will be needed. The solar, wind, and storage land mass could exceed 100,000 square miles, depending on who you ask. The good news is that plenty of raw renewable energy resources exist in the US. The bad news is they are not near areas of high demand. The answer is that the US will need to add significant transmission capacity to meet the 2050 goals. Some estimate that moving that power to where it is needed will require two to three times the current capacity.
The map on the left illustrates the nation’s transmission grid and state-level energy consumption data provided by the DOE’s Office of Energy Information Administration. The map on the right displays areas with the highest solar potential.
The Panglossian Illusion?
The US has about a quarter million miles of high-voltage transmission. Today, it can take a decade to build a single transmission line. To meet our 2050 goals, we could need one-half to three-quarters of a million miles of transmission. Is building this much transmission the Panglossian Illusion? Maybe.
Given that the renewable resources are not necessarily near the existing grid, it means building lines from the solar and wind farms. Still, it also means that the existing grid must handle the additional power to deliver to the load. New lines will certainly be needed here as well. But there may be other ways to skin that cat.
Here are five ways to upgrade the grid capacity by squeezing as much as possible out of the existing grid and taking advantage of location technology.
Implement Dynamic Ratings Using New Technology
Transmission lines are rated to represent the maximum safe capacity for carrying electrical power. The rating considers several factors such as thermal limitations of transmission conductors and equipment. The static line rating can be adjusted for seasonal changes, but this is still considered a static rating. There is an effort to develop dynamic line ratings to improve the efficiency of transmission capacity. Dynamic line ratings (DLR) continuously adjust based on real-time conditions on temperature, wind, humidity, solar radiance, and conductor line tension while maintaining a safe operating capacity.
In December 2021, FERC issued Order No. 881 to improve the accuracy and transparency of electric transmission line ratings. The order requires public utility transmission providers to implement ambient adjusted ratings (AAR) on their transmission service lines to enable hourly dynamic transmission ratings. AAR is consider an intermediate step toward full dynamic line ratings. The public utility’s dynamic ratings are to be shared with their respective market monitors in RTOs/ISOs and develop a maintained database of their ratings and methodologies. The commission explained that improving the accuracy of transmission line ratings will help ensure reasonable wholesale interstate rates and result in significant operational reliability and economic benefits. The deadline for implementation of requirements is July 2025.
There are several geographic factors to consider when developing an accurate dynamic line rating system. Latitude, topography, elevation, vegetation, surface ground cover, proximity to water features, and atmospheric wind direction are all important considerations for DLR. This is a perfect example of how GIS (geographic information systems) can be utilized for developing the DLR model. By inclusion of geographic features in layers, we can establish the most effective sensor locations for DLR delivering real-time data on conductor line tension, temperature, humidity, wind speed, direction, and solar irradiance.
Taking this even further, AI, machine learning, and digital twin technologies provide strong capabilities for this use case. Combining all these technologies, we have the GeoAI Digital Twin. This rapidly advancing technology is being leveraged to increase asset productivity and would be a perfect application for dynamic line ratings.
Integrate Topology Modeling to Increase Transmission Capability
Driving from Los Angeles to Palm Springs, you can’t help but notice scores of huge wind turbines. But often, many of the turbines are not spinning. Why is that? Are they broken? Unlikely. The issue is that there are times when, if all the turbines are generating, there would be too much power to meet the load. How can that be? The real issue is that the transmission system can’t transport power to areas relying on fossil fuels due to transmission congestion. Congestion also results in the inability to deliver low-cost energy to high-cost areas.
According to a recent US Department of Energy report, most transmission upgrades were for resilience, not capacity upgrades. GIS can help regional and interregional transmission planners lower transmission congestion, thus delivering wind and solar energy to where it is needed. Lowering congestion also reduces the need for power to take roundabout routes to reach the intended locations.
Planners can identify areas where land clearances limit transmission capacity. For example, a transmission segment’s right of way may have high grounds that limit the capacity of a line. Accurate modeling of the lines in GIS will help planners locate areas where clearance is an issue and help operators improve them.
Build Enhanced Modeling of Transmission Networks
Planners and real-time operators have modeled bulk power systems for decades. Algorithms for load flow, stability, state estimation, and short circuit analyses date back to the 1960’s. Yet the integration of these systems with GIS has been spotty. Integrating simulation and spatial tools allows planners and operators to see patterns that facilitate optimal planning and operations. For example, weather and climate impacts are modeled extensively in GIS. 3-D representations and advanced network networks are commonplace in GIS. Yet, the integration with well-known simulation tools is not. This integration creates ah-ha moments to enable better optimization of the grid. Check out how GIS can support engineering and design.
Leverage Highway and Railroad Right of Ways
Cat Clifford, noted a climate innovation and technology reporter, once quipped, “Building transmission lines in the US is like herding cats. All of the stakeholders in the construction of a new line — utility companies, regulators, landowners — have to come to an agreement, and they may have competed interest.” The herding process takes a lot of time. While it certainly takes time to build new lines, the permitting process may be more difficult and time-consuming. One way to short-circuit the issue is to leverage existing right-of-ways along highways and possibly rail lines. Learn about this approach here.
Take Advantage of New Technology for Existing Transmission
Of course, one of the best approaches to adding additional transmission capability that avoids the herding of cats is to upgrade the existing lines. GIS can be an essential tool to identify which lines are served best by upgrading. Perhaps the best way to start is to look for transmission congestion areas and areas with unscheduled power flows (which limit capacity). Entsoe (European Network of Transmission System Operators for Electricity) advocates for using high-temperature, low-sag (HTLS) conductors, which increase the capacity of existing lines. Read about it here.
Location Technology Provides the Framework for Dispelling the Panglossian Illusion
The Grid Panglossian Illusion suggests that by 2050, we will have completely decarbonized the bulk energy supply and have more than enough transmission capacity. Maybe. But to get there, we will have to be pretty creative. GIS can guide planners in selecting the optimal places to increase capacity by discovering areas to add new technology to existing lines, leverage existing rights of way, and improve modeling. While we can’t avoid building new lines, we can be smart by thinking outside the box.
Learn how to leverage GIS for electric utilities. Examine what EPRI can do for your utility.