Palau Public Utilities Corporation (PPUC) serves approximately 7,000 customers across the Pacific Island nation, with 80% being residential customers. When faults occurred, the utility dispatched crews to remote areas of its 114 miles of 13.8kV distribution lines.
The utility faced some notable reliability challenges with load distributed from the main population center in the south of the island, along long lines running to the north. Overhead lines across the island are exposed to severe weather and rapid vegetation growth, contributing to an average of 167 outages per year—roughly an outage almost every other day.
These trips were time-consuming and expensive due to the difficulty accessing areas with overgrown vegetation, resulting in extended outage times for customers. The service visits also had environmental implications, as each truck roll produced carbon emissions.
PPUC began investigating options to improve reliability and sustainability that would meet its requirements:
- Address the core reliability and resilience issues caused by repeated and avoidable outages, as well as the associated financial and environmental costs.
- Create a more stable grid to support transitioning from diesel generation to renewable resources and the country’s vision to become more energy self-sufficient.
- Accommodate a constrained budget yet deliver meaningful results—a common challenge for island nations where budgets often limit infrastructure upgrades.
The utility evaluated several automation options, including load-break switches, three-phase reclosers, and single-phase reclosers, to determine which solution would meet its requirements.
The PPUC consulted with S&C Electric Company to explore potential solutions. S&C shared examples of how similar technologies had been applied in other island nations and regions with severe weather challenges. Following these discussions, PPUC chose the TripSaver II Cutout-Mounted Recloser for overhead system protection.
The TripSaver II recloser tests for transient faults and restores power automatically, preventing sustained outages and unnecessary truck rolls. With up to 80% of faults on overhead lateral lines caused by temporary issues, the reclosers offered benefits for PPUC’s reliability challenges with storm debris and high vegetation growth.
Based on their design, these reclosers also provided flexibility, easy integration, and improved restoration with their:
- Variety of TCC curves and sequence coordination feature, making it easy to replace fuses and segment long laterals by applying devices in series to isolate permanent faults
- Visible drop-out functionality for easier fault location identification and more targeted restoration efforts immediately upon deployment
PPUC installed 62 reclosers at strategic locations across its distribution network. Of particular focus were the northern and eastern regions of the main island where outages were most common and harder to access.
PPUC utilized S&C’s services for training as well. Instead of the usual on-site training model, the vendor met PPUC’s needs for remote training, offering video training and support in order to deliver a successful deployment.
Within three years of installation, the devices:
- Cleared 428 temporary faults that previously would have become permanent outages, significantly improving reliability across the network
- Reduced carbon emissions by approximately 2.5 tons
- Delivered an average payback period of 1.5 years
|
OUTAGES PREVENTED BY LOCATION
|
|
LOCATION
|
TEMPORARY FAULTS
|
|
A
|
47
|
|
B
|
11
|
|
C
|
13
|
|
D
|
56
|
|
E
|
9
|
|
F
|
17
|
|
G
|
92
|
|
H
|
8
|
|
I
|
21
|
|
J
|
122
|
|
K
|
32
|
|
TOTAL
|
428
|
Temporary faults cleared by location over three years since installation.
The utility saved an estimated US $214,000 in operational cost reductions.
Beyond the immediate reliability and cost improvements, the recloser implementation has supported PPUC’s broader goals of transitioning from diesel generation to renewables. By improving grid stability and reducing outages, the utility has created a more reliable foundation upon which renewable energy resources can be integrated.
The success of the initial deployment has led PPUC to continue investing in single-phase recloser technology across its system. With the local population increasing and the ever-present threat of storms, PPUC has reshaped its fault-management strategy by relying on the recloser to avoid outages and their inconveniences.
