Ground Level Distribution
Hybrid undergrounding options such as Ground Level Distribution Systems (GLDS) where the lines are neither left in the air nor trenched and buried underground is a compelling concept. Traditional excavation methods continue to present many challenges including:
- Rocky geologies that increase the time and cost of excavation
- Time consuming permitting for archeological and religiously sensitive areas
- Removal or treatment of excavated soil adds cost and time
- Presence, of contaminants extends project timelines or may require re-routing
The Ground Level Distribution System is being demonstrated in the field at one utility. The system is additionally being evaluated in a laboratory environment at the EPRI Lenox test facility to begin answering some key resilience questions including:
- How does the encasement on the cable impact its current carrying capacity (ampacity)?
- How well do the GLDS protective structures protect the cable system from vertical impacts, such as tree impacts, and crush events, such as vehicles driving over it?
- What is the longevity and survivability of GLDS structures?
- What effect do repairs to the top cap and geopolymer concrete have on the strength of the structure?
- How may the cable system be maintained over its life?
Overall, the testing is designed to provide early insights into questions associated with safety, robustness, fire immunity, ampacity, thermal performance, and fault protection. This leads to a compelling opportunity for EPRI, DOE and the power industry to accelerate the use of GLDS and similar hybrid undergrounding approaches that can serve to meet industry objectives to reduce ignition incidents exponentially. For further information the following links are available.