WAPA Says it has Identified Cause of Tuesday Night’s District-Wide Blackout in St. Thomas and St. John

ST. THOMAS — The Virgin Islands Water and Power Authority said Wednesday that the cause of a district-wide blackout in St. Thomas and St. John on Tuesday night occurred when generating Unit 25’s protection control system detected high temperature at the power turbine. The unit performed as expected, by shutting down, to avoid extensive damage, WAPA said.

WAPA, under unending pressure from multiple directions, has been trying hard to keep the lights on so as to not irritate an already sensitive situation.

WAPA Chief Operating Officer of Electric Systems Clinton T. Hedrington, Jr. said Wednesday that the high temperature indication, caused by a water injection pump failure, triggered the shutdown of the unit which resulted in the loss of Unit 26. “Unit 26’s new fuel regulating valve performance has improved but the generator’s response to grid swings and surges is still not quite where it needs to be. Unit 23, a WAPA-owned generator, was recently returned to service and will be dispatched more frequently until additional adjustments on Unit 26 are completed, and the unit is proven reliable,” Mr. Hedrington said.

At the time of the outage, WAPA’s three propane-fired Wartsila generators were online, as were Units 25 and 26, a pair of rental units that utilize Number 2 oil (diesel) to generate electricity. The combined five units were generating more than 51 megawatts of electricity, the utility said.

Executive Director Lawrence J. Kupfer thanked the plant personnel for their efficiency in minimizing the duration of the service interruption. Looking to the future, he noted that in 2020, WAPA will use federal funding to purchase and install an additional 40 megawatts of propane-fired generation to the Harley power plant to provide more efficiently-produced, lower cost, and reliable electric service to its customers.

“The next step in this process occurs later this week when WAPA receives bid packages in response to a previously-issued Request for Proposals for the expanded generation capacity. WAPA’s efforts continue each day to build a more reliable, affordable, and efficient electric system for the Virgin Islands,” Mr. Kupfer said.