We have no inside knowledge to dispute HECO’s explanation and, in fact, we’re not disputing it. Lightning apparently was the cause, and without the storm, power presumably would have been uninterrupted.
But we can’t help wondering about whether something designed into the power grid failed to isolate the problem. That issue hasn’t been addressed in any media reports we’ve seen, and far as we can tell, HECO’s representatives have avoided talking about that possibility.
HECO’s explanation suggests lightning strikes created grid instabilities that inevitably required all the generators on the island to shut down. We and others are left to wonder whether those shutdowns truly were inevitable. Is it possible something failed to operate properly that, for example, might have allowed the Honolulu power plant to remain online and provide power to the circuits it serves?
Black Wednesday’s Finding
Oahu experienced an island-wide power outage on July 13, 1983 that a study determined might have been avoided if the system had reacted as it was designed to operate. Both these outages – December’s and back in 1983 – involved unusual “three phase faults.”
Stone & Webster published its report on the “Black Wednesday” outage in 1984. Here’s a reference to that outage from a PUC docket:
“A three phase fault occurred on the Kahe-CEIP 138kV line and then relays mis-operated to trip three additional 138kV lines leading to the system blackout. The relay mis-operation contributed to the blackout, and had the relays operated properly the outage may have been avoided.”
The report goes on to note that the transmission system was vulnerable because two additional 138kV lines were out of service for maintenance. But the “mis-operation” of those relays, or circuit breakers, was seen as key. Our recollection of the incident (as HECO spokesperson at the time) was that the relays were set to react within a third of a second after a disruptive incident, such as the 1983 cane fire that caused the flashover, but should have been set to operate even faster to isolate the problem.
If something could “mis-operate” in 1983, it seems plausible something similar could have happened last month. And that’s all we really want to know about the electric system’s reaction to the lightning: Was the generator blackout truly inevitable, or might something have tripped earlier along the transmission system that would have prevented the collapse.
It would seem highly unlikely that the engineering report eventually published about the December outage will conclude there’s no defense to Acts of God. Someplace, somewhere surely there is a system designer who knows how to keep the system operating, even when He steps in.
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