Underground power lines are no longer a luxury reserved for master-planned communities and downtown business districts. They are becoming the default infrastructure choice for utilities, municipalities, and developers across the United States. A combination of devastating wildfires, record-breaking hurricane seasons, aging overhead infrastructure, and surging electricity demand from data centers and electric vehicles has created a once-in-a-generation shift toward burying the nation's electrical grid.
For contractors who install conduit, build duct banks, and pull cable, this shift represents a massive and sustained expansion of available work. Understanding what is driving the trend, which programs are funding it, and what materials and methods are required positions contractors to capture a growing share of this market.
Why Utilities Are Accelerating Undergrounding Programs
The push to bury overhead power lines has been building for decades, but several converging forces have accelerated the timeline from "eventually" to "right now."
Wildfire Prevention
Overhead power lines have been identified as ignition sources in some of the most destructive wildfires in U.S. history. The 2018 Camp Fire in California, which destroyed the town of Paradise and killed 85 people, was traced to PG&E overhead equipment. The 2023 Lahaina fire in Maui was similarly linked to downed power lines. Texas's largest wildfire on record, the Smokehouse Creek Fire, burned over one million acres in February 2024 after being ignited by a fallen pole that had already been reported as decayed.
These events have driven regulatory mandates. California's SB 884, which took effect in early 2023, requires the state's largest utilities to submit 10-year undergrounding plans prioritized by wildfire risk. PG&E responded with the most ambitious undergrounding program in the country. Since announcing its program in 2021, PG&E has completed more than 1,200 miles of underground power lines, hitting its 330-mile goal for 2025 and targeting 440 miles in 2026 with a long-term objective of 10,000 total miles.
Hurricane and Storm Resilience
Florida Power & Light (FPL) has provided some of the most compelling performance data for underground power lines through its Storm Secure Underground Program. During the 2024 hurricane season, which included Hurricanes Debby, Helene, and Milton, FPL reported that underground neighborhood power lines performed 5 to 14 times better than overhead lines. On a day-to-day basis, underground lines perform approximately 50% better than overhead.
The Babcock Ranch community near Fort Myers, which was designed from the ground up with underground power, never lost electricity during Hurricane Milton. FPL has now completed more than 3,000 Storm Secure Underground Program projects across its 35-county service territory and relocated 90 miles of overhead lines underground in northwest Florida alone. FPL reports that approximately 45% of its distribution system is already underground, compared to about 30% for utilities nationwide. About 90% of the new distribution lines FPL installs are underground.
Grid Modernization and Demand Growth
The U.S. power grid is simultaneously reaching the end of its design life and facing unprecedented demand growth. AI-driven data centers, electric vehicle charging infrastructure, and industrial electrification are driving what industry analysts call a once-in-a-century infrastructure buildout. The power distribution segment of underground construction is projected to grow at over 7.5% annually through 2027. The global electrical conduit market is expected to reach $20.9 billion by 2033, registering an 8.4% compound annual growth rate from 2026 to 2033.
This demand growth requires not just new generation capacity but upgraded and expanded distribution infrastructure. Underground systems built today need to accommodate higher loads and more circuits than systems designed 30 or 40 years ago, which is why modern duct bank configurations often include spare conduits for future cable additions.
What Undergrounding Programs Look Like on the Ground
Understanding how undergrounding projects are structured helps contractors prepare bids, plan equipment needs, and build crews for this work.
Overhead-to-Underground Conversions
Conversion projects replace existing overhead distribution lines with buried conduit and cable. The typical workflow includes surveying the existing overhead route, marking and potholing existing underground utilities, trenching or boring the new conduit route at 24 to 48 inches of cover, installing conduit (typically PVC Schedule 40 for duct bank construction or HDPE for trenchless runs), pulling new underground-rated cable through the conduit, installing pad-mounted transformers and switching equipment, connecting the new underground system and transferring load, removing the old poles and overhead conductors, and restoring surfaces.
These projects move through established neighborhoods where existing utilities, landscaping, driveways, and sidewalks create tight working conditions. Contractors experienced in horizontal directional drilling (HDD) have an advantage here because FPL and other utilities have adopted low-impact directional boring as the primary installation method to minimize disruption to customer properties.
Direction changes in duct bank systems use DB-100 PVC sweeps to maintain the large-radius bends required for pulling medium-voltage cable without exceeding manufacturer tension limits. Every bend in the conduit run increases pulling tension, so specifying the correct sweep radius at the design stage directly affects whether the cable pull succeeds on the first attempt.
New Development Underground Construction
In new residential and commercial developments, underground power lines are increasingly required by code or developer preference. FPL reports that about 90% of its new distribution lines are installed underground. New construction offers significant advantages over conversion work: clean trenches without existing utility conflicts, the ability to coordinate conduit installation with other underground services, and the opportunity to install spare conduits for future telecom or fiber.
Forward-thinking developers and utilities are installing FuturePath microduct alongside power conduit during initial construction to provide pathways for fiber optic service without future excavation. A single FuturePath assembly provides up to eight individual microduct pathways inside one HDPE outer shell, which means one additional pull during the initial trenching phase eliminates the need for separate telecom construction later.
Utility-Scale Grid Hardening
Large-scale grid hardening programs like those run by PG&E, FPL, Georgia Power, and Consumers Energy in Michigan combine undergrounding with overhead hardening (covered conductors and stronger poles) based on risk analysis of each line segment. Contractors working on these programs may be undergrounding one section while hardening overhead lines in another, requiring crews skilled in both disciplines.
The U.S. Department of Energy's ARPA-E program has funded $34 million through the GOPHURRS initiative (Grid Overhaul with Proactive, High-speed Undergrounding for Reliability, Resilience, and Security) to develop technologies that cut undergrounding construction time and cost by up to 50%. These include concurrent drilling and conduit installation systems that eliminate the separate bore-then-pull sequence used in conventional HDD.
Conduit and Material Requirements for Underground Power
Underground power distribution conduit must meet more demanding specifications than telecom or low-voltage conduit because of the heat generated by medium-voltage and high-voltage conductors, the pulling forces involved in long cable runs, and the consequences of conduit failure when energized cables are involved.
Duct Bank Construction
The standard duct bank for underground power distribution uses rigid PVC conduit (Schedule 40 or Type DB) encased in concrete. Typical configurations range from 2x2 (four conduits) to 3x3 (nine conduits) depending on the number of circuits, with minimum 3-inch concrete cover on all sides and 3-inch center-to-center spacing between conduits. Reinforcing steel is used for duct banks under roadways or areas subject to vehicular loading.
Conduit spacing is critical for heat dissipation. Cables operating at their rated ampacity generate heat that must transfer through the conduit wall, into the concrete encasement, and then into the surrounding soil. Insufficient spacing between conduits creates thermal hotspots that derate the cable's capacity and accelerate insulation aging.
HDPE Conduit for Trenchless Installation
For bore runs using horizontal directional drilling, HDPE conduit is the standard material because it can withstand the tensile forces of pullback without cracking and flexes with ground movement over its 50- to 100-year service life. HDPE's smooth interior wall also reduces friction during cable pulling, which matters significantly on long runs where cumulative pulling tension approaches cable manufacturer limits.
Monitoring pulling tension with a tensiometer during every cable installation protects both the cable warranty and the conduit system. Exceeding recommended pulling tension can damage cable insulation, stretch conductors, or crack conduit at bends and joints, creating failure points that may not manifest for months or years after installation.
HDPE field joints made with double E-Loc couplings provide tool-free mechanical connections that maintain watertight integrity without heat fusion equipment. For bore runs where the conduit must withstand pullback forces, butt fusion joints are standard because they create a joint as strong as the pipe itself.
Protecting Open Conduit and Completed Systems
Every conduit end that is not immediately receiving cable should be sealed with vinyl end caps to prevent water, mud, debris, and insects from entering the system. This is particularly important on undergrounding projects where duct bank sections may be installed weeks or months before cable is pulled. Contamination inside conduit increases pulling friction, risks cable jacket damage, and can require costly cleaning or mandrel testing to clear obstructions.
After backfill, woven barricade tape rated at 500 pounds tensile strength is buried approximately 12 inches above the conduit to warn future excavators of the buried utility before they reach the conduit itself. Given that third-party dig-ins remain one of the most common causes of underground utility damage, this simple step provides the last layer of protection against accidental cable strikes.
What This Means for Contractor Workforce and Equipment
The undergrounding boom is creating sustained demand for contractors with specific capabilities, and the workforce shortage facing the construction industry is amplifying the opportunity for firms that are prepared.
Crew and Equipment Requirements
Underground power line installation requires crews trained in trenching and shoring, horizontal directional drilling, duct bank forming and concrete placement, medium-voltage and high-voltage cable pulling, cable splicing and termination, and pad-mounted transformer installation. Contractors who can self-perform multiple disciplines on a single project offer utilities lower coordination costs and faster timelines, which translates to more consistent award of task-order and blanket contracts.
Equipment requirements include HDD rigs (typically in the 20,000 to 100,000 lb pullback range for distribution work), vacuum excavation trucks for utility locates and potholing, cable pulling equipment with calibrated tension monitoring, and concrete delivery coordination for duct bank encasement.
Scaling to Meet Multi-Year Programs
The largest undergrounding programs are structured as multi-year commitments. PG&E's 10,000-mile program will run for a decade or more. FPL's Storm Secure Underground Program adds hundreds of projects annually. San Diego's municipal undergrounding program had 58 projects totaling $760 million underway in 2025, up from 45 projects and $590 million in 2024.
Contractors who invest in building dedicated underground crews, maintaining relationships with conduit and cable suppliers, and developing efficient installation methods will find these programs provide reliable, recurring revenue. The Associated Builders and Contractors (ABC) estimates the construction industry needs approximately 500,000 additional workers in 2026 just to keep pace with overall demand, which means contractors who can recruit and retain skilled underground utility workers will have a significant competitive advantage.
Undergrounding Costs and Funding Sources
Cost remains the primary barrier to faster adoption of underground power lines, but multiple funding mechanisms are making projects financially viable for more communities.
Current cost benchmarks for overhead-to-underground conversion range from $3 million to $5 million per overhead pole-mile according to Kimley-Horn's 2025 project experience, though costs vary significantly based on soil conditions, existing utility density, depth requirements, and restoration scope. New construction undergrounding is substantially less expensive because it avoids the dual-system phase where overhead and underground operate simultaneously during cutover.
Funding sources include utility rate cases approved by state public utility commissions, municipal special assessments and bond sales, FEMA Hazard Mitigation Grant Program funding, the DOE Grid Hardening State/Tribal Formula Grant Program, HUD Community Development Block Grant (CDBG-DR) disaster recovery funding, and developer-funded installation in new construction.
The financial case for undergrounding strengthens with every major storm event. FPL's 40-year net present value analysis found that storm hardening savings (including undergrounding) equate to $653 million for a storm occurring once every three years. Underground systems also eliminate ongoing vegetation management costs, which are a significant annual expense for utilities with overhead lines in wooded or suburban areas.
About Utility Pipe Supply
Utility Pipe Supply is a certified Woman-Owned Business Enterprise (WBE) headquartered in Illinois, providing HDPE conduit, PVC duct, fiberglass conduit, fittings, cable pulling accessories, and installation tools to underground utility contractors nationwide. With over 25 years of experience and in-stock inventory across the conduit types and accessories required for distribution undergrounding projects, we help contractors build underground power lines that perform for decades.
Frequently Asked Questions
Why are utilities burying more power lines?
Utilities are accelerating undergrounding to prevent wildfire ignitions from downed overhead lines, improve storm resilience (underground power lines performed 5 to 14 times better than overhead during the 2024 hurricane season in Florida), meet regulatory mandates like California's SB 884, and accommodate growing electricity demand from data centers and EV charging. The shift is supported by federal grant programs and utility rate cases that make large-scale undergrounding financially viable.
How much does it cost to bury power lines underground?
Overhead-to-underground conversion currently costs between $3 million and $5 million per pole-mile based on 2025 project data. Costs vary based on soil conditions, existing underground utility density, burial depth, cable voltage, and surface restoration requirements. New construction undergrounding costs significantly less because it avoids the complexities of converting an existing overhead system while maintaining service.
What types of conduit are used for underground power lines?
PVC Schedule 40 and Type DB conduit are the standards for concrete-encased duct bank construction. HDPE conduit is used for trenchless installations via horizontal directional drilling because of its flexibility and pullback resistance. Fiberglass (RTRC) conduit is specified for harsh environments including coastal areas, chemical plants, and installations requiring a wider temperature operating range. The conduit type depends on the installation method, soil conditions, and environmental exposure.
How does undergrounding affect contractors and the construction workforce?
The undergrounding trend is creating sustained, multi-year demand for contractors with trenching, HDD, duct bank construction, and cable pulling capabilities. PG&E alone is undergrounding 300 to 440 miles per year. FPL adds hundreds of projects annually. The construction industry already faces a shortage of approximately 500,000 workers, so contractors who build and retain skilled underground utility crews will have strong competitive positioning for years to come.
What is the lifespan of underground power line systems?
Underground conduit systems built with HDPE have an expected service life of 50 to over 100 years. PVC conduit provides 50 to 70 years of reliable performance in appropriate conditions. The cable inside the conduit typically has a design life of 30 to 40 years but can be replaced by pulling new cable through the existing conduit without re-excavation, which is one of the primary long-term cost advantages of conduit-based underground systems over direct burial.
How do underground power lines perform during hurricanes?
FPL's data from the 2024 hurricane season (Hurricanes Debby, Helene, and Milton) showed underground neighborhood power lines performing 5 to 14 times better than overhead lines. The Babcock Ranch community near Fort Myers maintained full power throughout Hurricane Milton because its entire electrical distribution system was built underground from the start. Underground systems are not affected by wind, falling trees, or flying debris, which are the leading causes of overhead power outages during tropical storms.
What federal funding is available for undergrounding projects?
Multiple federal programs support undergrounding, including the FEMA Hazard Mitigation Grant Program, the DOE Grid Hardening State/Tribal Formula Grant Program, and HUD's Community Development Block Grant (CDBG-DR) disaster recovery program. The DOE also funded $34 million through the GOPHURRS initiative to develop faster and less expensive undergrounding construction technologies. State and local funding through utility rate cases and municipal bond programs provides additional financing pathways.
Get the Materials Your Underground Crews Need
Utility Pipe Supply stocks PVC conduit, HDPE conduit, fiberglass conduit, sweeps, couplings, seals, pulling accessories, and all the materials contractors need for underground power line projects. Call us at (815) 337-8845 or request a quote to get pricing and availability for your next undergrounding project.