A preliminary report submitted to the Office of Utilities Regulation (OUR) by the Jamaica Public Service Company (JPS) into last Friday’s islandwide blackout suggests that it was triggered by similar issues which caused a collapse of the national grid on at least three occasions in the past.

The report, which has been seen by Jamaica Observer, was submitted to the OUR on Tuesday, but so far there has been no public statement from the regulator.

However, Energy Minister Daryl Vaz is livid that the country was left in darkness after the JPS was given instructions in the past to prevent a repeat of the system failure.

“I can confirm that I received the preliminary report from the JPS as it relates to Friday’s all-island outage and, even though it is preliminary, it indicates a system failure — nothing different from all the other all-island outages. The first one we had was in 2006 and now it is 2026 and we still having the same system failure of different sorts,” said Vaz.

“This is totally unacceptable, especially in the light that 20 years have passed and we are now in age of technology. It should not happen, and I can indicate that we will be pursuing an independent consultant to review the final report — which is due after 30 days — to ensure that this matter is addressed once and for all,” added Vaz.

He told the Observer that the OUR’s recommendations to prevent a system failure on the JPS grid, which could lead to an all-island blackout, are all on record and that these will be reviewed.

“Because we are still having the same issues and the Jamaican people are sick and tired of it, and so am I,” declared Vaz.

He pointed to the example of the August 2012 islandwide blackout which occurred after lightning struck a pole located on the Duhaney to Naggo Head 69 kilovolt (kV) transmission line, as Tropical Storm Ernesto passed near the island.

At that time the OUR found the blackout to be, “typical of those which precipitated the three earlier system shutdowns, including the first major incident in 2006”.

The OUR added in that report, “Human error and maintenance shortcomings have played a part, as well as manifested deficiencies in the islandwide grid and generation infrastructure.”

According to the regulator in relation to the 2012 incident, the lack of a protection relay was “primarily blamed for precipitating the subsequent islandwide system collapse”.

It was a similar story this time around, as in its report JPS says preliminary analysis indicates that the event was initiated by multiple faults on critical 69kV infrastructure within the Corporate Area, specifically:

• two faults associated with the Rockfort Substation and the Hunts Bay–Rockfort 69kV transmission line, believed to be lightning-induced, and;

• a subsequent single phase-to-ground fault on the Hunts Bay–Port Authority 69kV transmission line.

According to the JPS, its physical inspection confirmed: “a damaged insulator at location 41 on the Hunts Bay–Rockfort 69kV line; a flashover event at the Rockfort 69kV substation disconnect switch; and a broken conductor on the Hunts Bay–Port Authority 69kV line”.

The company said its protective relays correctly detected the disturbance and initiated tripping at multiple substations including Greenwich Road, Duhaney, Rockfort, Hunt’s Bay, and Port Authority.

“However, the sequence of trips and system behaviour strongly suggests a failure or delayed operation of the primary protection scheme at Hunt’s Bay on the Rockfort line, resulting in extended fault duration; escalation of the disturbance; and wider propagation of system instability through remote tripping actions,” the company said.

It added that its sequence of events (SOE) data indicates that the trip of the Jamaica Private Power Company Unit 1 generator preceded the cascading loss of additional generating units at Hunts Bay, West Kingston Power Plant, and other plants across the system.

“The resulting rapid loss of generation created a severe generation-load imbalance, triggering all five automatic under-frequency load shedding (UFLS) stages… Despite the operation of these schemes, the magnitude and speed of generation loss exceeded the system’s ability to stabilise,” said the report.

The JPS said this led to continued generator trips at its plants and that of private power suppliers, resulting in “a complete shutdown of the interconnected system, resulting in an all-island outage”.

The company told the OUR that following the shutdown it activated its incident command structure and commenced restoration using a controlled black-start and system build-up approach, initially isolating the affected Corporate Area assets.

“Restoration proceeded through the establishment of separate electrical islands,” the JPS noted.

It said it has since initiated actions to stabilise the system and mitigate recurrence risk. These include a continued detailed analysis of relay operations and SOE data across all affected substations, and a comprehensive review and validation of line protection schemes, with particular focus on the Hunt’s Bay–Rockfort corridor.