Two-hour blackout hits Saipan

Operator error and a lack of reserve are being blamed for the 2.5-hour islandwide blackout that occurred yesterday morning and cost the Commonwealth Utilities Corp. several thousand dollars.

At 7:28am, an operator put a generator on standby just as demand was increasing and more engines should have been put online. Power Plant 4 went down first, then knocked off the Aggreko generators, forcing 18 megawatts of power demand on Power Plant 1, far more than it can handle.

“The system rejected it and the whole system collapsed,” said Wallon Young, deputy director for Utilities System Rehabilitation.

Power was restored to the island around 10 am.

The loss of customer usage during the few hours probably cost the utility agency several thousands dollars, CUC executive director Antonio Muña said.

As CUC repairs and brings in more engines, the utility company works to conserve fuel. The utility company is working to restore several engines at Power Plant 1, in order to be ready for September, when the one-year contract with Aggreko ends.

The Aggreko engines have been providing 15 megawatts of power to the island since Sept. 11, virtually halting the blackouts and rotating brownouts that had plagued the island. CUC recently brought back online engines 7 and 3 at Power Plant 1 after months of rehabilitation. Muña said the engines were not damaged from the blackout.

The island demand has increased on weekdays from 37 to 39 megawatts, while fuel usage has remained fairly stable. When demand was 37 megawatts, CUC was using 58,000 total gallons of fuel each day at Power Plant 1 and Power Plant 4. Since March 31, when engines 7 and 3 were brought online and demand increased to 39 megawatts, the utility agency has only been using an additional 100 to 200 gallons of fuel, he said.

“So, essentially, we’re producing more with less fuel consumption,” the executive director said. “We operate with a very thin line on a spinning reserve. This morning, essentially what happened, the operator basically took our spinning reserve offline at a critical moment when he was trying to establish stability in our frequency.”

Muña said he believed protocols were in place so events like yesterday’s blackout would not occur. The remedy, he added, is to revisit operation protocol.

“As much as we’d like to save or maximize on fuel savings, it looks like we may need to revisit to what extent we have a spinning reserve available to us at any given point in time,” he said.

He added that it’s a delicate balancing act.

“We felt we had the right kind of protocol in place, considering numbers and demand and not seeing a significant increase in fuel,” he said. “We thought we had something, the protocol was sufficient. But it appears in speaking with Mr. Wallon Young, and at the same time other staff, we’re going to have to revisit that and readdress that issue.”

During the news briefing, Gov. Benigno Fitial asked Muña if the operator in question was still employed with CUC.

”Yes sir. We are re-educating our operators and ensuring the proper remedy is in place,” Muña said, adding that he takes some responsibility.

“I monitor the fuel cost savings. From my standpoint, when you’re producing more and meeting demand and your fuel costs are not significant in terms of increase, it is a positive situation,” he said. “Obviously, it’s also to a certain degree, as far as being a hire wire act, we just need to lower the height a little bit.”

Young, when asked how much is adequate reserve, said it should be equal to the largest unit online, which was 10 megawatts yesterday morning. But to have a 10-megawatt reserve, the engines would need to run at 50 percent.

“Now that’s not a very efficient way to run diesel engines,” he said.

There is an increase in costs when the spinning reserve is increased because engines are not running at their optimal efficiency, Young said. To run diesel engines at 50 to 60 percent, more fuel will be consumed but producing the same amount of kilowatt hours.

Asked if it was impossible to predict yesterday’s outage would happen, Young said: “It was a not so good call by the operator this morning to shut down or to put one engine on standby when the load was coming in this morning. He made the decision because when he looked at the system frequency, it was high. He assumed there were too many engines online.”