As utilities look to improve grid resilience, undergrounding is often initially viewed as the obvious answer – safer, stronger, and more reliable. But in reality, the decision between underground and overhead infrastructure is far more nuanced. Resilience isn’t about choosing one solution universally; it’s about understanding performance, cost, and long-term system behavior.
The most resilient grids are built through informed tradeoffs, not assumptions.
Understanding the Tradeoffs: Cost, Performance, and Lifecycle
Underground systems offer clear advantages in certain environments. They are less exposed to wind, ice, and vegetation, and can reduce outage frequency in high-impact areas. However, these benefits come with significantly higher upfront costs and more complex lifecycle considerations.
Typical cost ranges illustrate the difference clearly:
- Overhead distribution: approximately $300,000–$1 million per mile
- Underground distribution: approximately $1 million–$5+ million per mile, depending on soil conditions, congestion, and permitting
- Transmission undergrounding: can be 5–10 times more expensive than overhead alternatives
From a lifecycle standpoint, underground systems often experience fewer outages, but when failures do occur, they take longer to locate and repair. Specialized crews, equipment, and excavation are typically required, which can extend restoration times. Overhead systems, while more exposed, allow for faster access, easier fault identification, and more flexible system upgrades over time.
Resilience is not just about avoiding outages – it’s also about how quickly and safely systems can be restored.
Where Each Approach Makes the Most Sense
High-performing utilities deploy underground and overhead systems intentionally.
Underground infrastructure is often best suited for dense urban environments, areas with limited right-of-way, or locations with frequent vegetation-related outages where restoration costs and customer impact are high. Overhead systems remain highly effective in rural areas, transmission corridors, and regions where access, visibility, and rapid restoration are critical.
Rather than pursuing blanket undergrounding, resilient utilities evaluate risk, customer density, environmental exposure, and long-term operating costs – applying the right solution to each scenario.
Building Resilience Through Design, Execution, and Maintenance
Whether underground or overhead, long-term performance depends less on placement and more on how infrastructure is designed, built, and maintained.
Proper grounding, material selection, constructability planning, and documentation play a significant role in lifecycle performance. Overhead systems benefit from modern structures, improved conductor materials, and proactive vegetation management. Underground systems perform best when installed with future access, standardized components, and long-term maintenance strategies in mind.
Partnering with experienced infrastructure teams ensures systems are built correctly the first time: reducing rework, improving safety, and extending asset life regardless of configuration.
Making the Right Decision for Your Grid
Grid resilience comes from informed decision-making that balances cost, performance, restoration capability, and lifecycle impact. Utilities that take a practical, system-wide view are best positioned to improve reliability today while preparing for tomorrow’s demands.
Learn how Kent Power can become your reliable infrastructure partner, helping utilities assess costs, lifecycle impacts, and construction methods to build resilient systems that last, at www.kentpower.com.
