Cabras unit 2, one of the oldest generators on Guam, will remain offline until Feb. 14 for a major overhaul, the Guam Power Authority announced Tuesday.
The unit is also one of the largest baseload generators on island at the moment, and so, the utility is asking customers to conserve energy when able - particularly during peak hours from 6 p.m. to 9 p.m.
GPA is not expecting any service interruptions from the overhaul, however.
Some power outages did occur last year during the conversion of Piti generation units to use ultra low sulfur diesel, because one of the units was unavailable and Cabras 2 went offline for repairs.
“Taking Cabras 2 offline allows us to make the necessary inspections, maintenance, and repairs to ensure that the baseload generator’s reliability is improved until the new 198MW Ukudu Power Plant comes online. We continue to work diligently to maintain the older units to increase their reliability and safety while improving the plant’s efficiency,” GPA General Manager John Benavente stated in a release.
The overhaul will include the replacement of archway tubes and gas and air duct expansion joints, maintenance of air preheaters and burner fronts, and an inspection and overhaul of the turbine generator, in addition to other maintenance. The total cost of the project is about $5 million, according to GPA.
The overhaul was first scheduled to begin in October, but was delayed as the utility waited for materials and specialized technical experts to arrive on island.
While they are needed for now, Cabras 2 and its sister unit, Cabras 1, are about half a century old and are scheduled for decommissioning after the Ukudu Power Plant comes online. Both units underwent conversions in 2022 that allow them to burn low sulfur residual fuel oil, GPA stated.
This was a key step in GPA's Clean Energy Master Plan, which is a move to become 50% reliant on renewable energy sources by 2030, and 100% reliant on renewable energy sources by 2045, according to the utility.
But the more immediate aspect to the conversion is that it complies with a federal consent decree requiring all of Guam's generators to switch to cleaner burning fuel to align with federal emissions standards for hazardous pollutants emitted by stationary reciprocating internal combustion engines.
The commissioning of the Ukudu Power Plant, scheduled for April 2024, and the decommissioning of Cabras units are also part of the federal consent decree, in addition to forwarding GPA's plan to move toward greater renewable energy, as the Ukudu plant is intended to facilitate the incorporation of more renewable energy sources.
The new plant has added fuel efficiency, and combined with renewable energy sources, it is expected to mitigate power costs for consumers, which has been increasing since February 2021 due to the fuel surcharge - the portion of the power bill that pays for fuel, which makes up most of a customer's monthly obligation to GPA.