Engineers now believe Scituate’s turbine was struck at least twice during a lightning storm on June 24, and while the machine has since been turned back on, problems have persisted.
Damage in two of the blades suggests the turbine was hit multiple times, and crews have been working for weeks to solve the issues.
Most of the fixes were finished by July 11; however, additional problems have surfaced since then, causing the machine to be shut off intermittently.
“It took us awhile to get … one component resolved and fixed. And we ran [the turbine],” said Sumul Shah, president of Lumus Construction and operator of the turbine. “With it running, there were some other things that showed up.”
Those problems have been resolved one by one, and while the machine has been fully running since Tuesday, fixes aren’t completely done, Shah said.
The ongoing issue has to do with an internal sensor that puts the turbine into an error mode every time the wind shifts suddenly.
Though Shah can manually clear the error, it will have to be repaired in the long term.
“There are still a couple of known errors that we have not fixed yet,” he said. “They don’t impact operations, but there are still some items we’ll need to fix. We’re not out of the woods yet. We have some more work to do.”
The work is only the latest ongoing in the machine. Since the June 24 storm, every fuse in the turbine had to be replaced, along with several wires and sensors.
Though Shah said the company had spare materials and parts in inventory to maintain the machine, which will ultimately be paid for by the manufacturer, and though labor costs are also covered by the manufacturer, the turbine has fallen behind in energy production.
The machine has missed out on an average of 198,900 kilowatt hours of energy production, or more than $23,000.
“We’ll be starting to look at that in a little bit, but I’m very much focused on resolving the issues with the turbine,” Shah said.
Once problems are completely resolved, engineers will look at how to possibly avoid future problems with lightning.
Turbines are built to handle a single lightning strike, Shah said, but multiple strikes are rare and difficult to deal with.
Shah wasn’t even sure if the machine was only hit twice. A lightning recorder in the machine should be able to tell the full story and analysis can go from there.
“The turbine is designed to protect itself when it happens once, but under such severe conditions, [lightning] can cause problems,” Shah said. “This is our first experience in Scituate dealing with this level of severity from a lightning storm, but our technicians have worked through this stuff before.”
Already conversations have begun with other turbine operators on how to deal with lightning, a necessary evil when you work in the clouds.
However, it’s unclear if situations like this can be avoided in the future.
“I’ve talked to a lot of people familiar with lightening strikes in other projects and they have spent lots of time, money, and engineering to chase down the source of the problem, and in the end there is nothing you can do to solve a severe lightning strike,” Shah said. “…Turbines get hit by lightning all the time. We’ve had other turbines hit by lightning and you barely notice it, but this is unusual because it was hit multiple times.”