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April 16, 2000

HEADLINE: Power Grid Needs Emergency Repair Job Failure Leaves Chittenden Co. Vulnerable

By JOHN DILLON Staff Writer

The electric transmission network that serves Chittenden County needs a multimillion-dollar emergency repair job that could require a new power plant to be installed temporarily in northwestern Vermont, utility officials say.

The Vermont Electric Power Co., which operates the state's high voltage transmission system, is asking utility regulators for emergency approval to install new lines, a large transformer and a new power plant in order to bolster the regional power system after a key piece of equipment failed March 22.

The equipment that failed - called a phase angle regulator - is located in Plattsburgh, N.Y., and controls the amount of electricity that flows over a high voltage line connecting New York and Vermont under Lake Champlain near the Sand Bar State Park.

Without the phase angle regulator in operation, the line itself could fail this summer when electricity demand increases, leaving Burlington vulnerable to blackouts, utility officials worry.

Electricity, like water, flows along paths of least resistance, according to where it is being generated and where it is being used. The regulator that failed "actually forces power to take a particular path. Its function is the keep the line across the lake from getting overloaded," said Thomas Wies, VELCO's general counsel. "If lines are overloaded, they'll burn up. The PAV (phase angle regulator) is a device to prevent that from happening."

Repairing or replacing the PAV could take up to a year. But VELCO officials worry that when demand for power increases this summer, the power line under Lake Champlain would become dangerously stressed.

So VELCO engineers have scrambled to come up with several potential solutions that would essentially keep the power network in balance and prevent the Lake Champlain line from becoming overloaded.

If the line did become overloaded this summer, operators would be forced to shut it down, which then would leave the region susceptible to blackouts, said Public Service Commissioner Richard Sedano, whose department represents consumers in utility cases.

"To avoid (line overload), they would open the switch so the line would no longer carry electricity. That would create problems because it would reduce the amount of electricity flowing into Chittenden County. It would leave Chittenden County more vulnerable than we would like to see," he said.

Sedano described the situation as a "slow moving" emergency, one that will get more severe as electricity use increases in late spring and summer.

"There is a significant amount of exposure. VELCO is doing what it can to minimize what it needs to address it, but there could be some significant proposals that they're going to ask to be installed relatively quickly," he said.

The repairs under consideration are designed both to keep the Lake Champlain line in operation, and to bring in alternative electricity supplies should operators be forced to shut the line down, according to documents filed with the Public Service Board.

VELCO wants approval to build a 115 kilovolt transmission line from its Irasburg substation to the Citizens Utilities network, new connections between Citizens Utilities' lines and Hydro-Quebec circuits at Highgate, and a large, new transformer in West Rutland.

VELCO is also considering installing a diesel power plant near its Sand Bar substation in Milton in order to produce 35 to 40 megawatts needed to strengthen the system, Wies said.

The company is seeking emergency authority for the work in order to get some of the improvements in place before hotter weather hits and power demand increases. The emergency waiver would allow VELCO to bypass the detailed environmental and cost review required for major power projects. Wies said if VELCO is given the emergency waiver, it would undergo full PSB review later in order to make all the repairs permanent, except for the proposed Milton power plant.

"The additional generation is something we would not ask to make permanent," he said.

VELCO also is reviewing state air quality regulations that could affect the power plant proposal, he said. "I don't know that even if the (PSB) thought it was a good idea whether we'd do it."

Small, portable power plants are not that easy to find. And the ones that are available are usually for sale, not for rent.

"These are not off-the-shelf items," Wies said. "We have a line on several possibilities, but we haven't signed any contracts. We're pretty sure something is available."

VELCO has not pinned down the cost of the various proposals, but the work will not be cheap. The phase angle regulator costs several million dollars. The upgrades to bolster the connections with the Citizens Utilities' system will also cost $2 million to $3 million, Wies said.

The question of who pays for the work has also not been answered, and depends in part on which improvements are made, he said. The cost of repairs to the New England transmission system are usually covered by all the utilities in the system, he said.

Wies said the work VELCO wants to do now under the emergency waiver is not part of a transmission upgrade the company considered several years ago as part of a plan to bring more power south from Hydro-Quebec. He said that project would have been valuable today because it would have made the transmission network more robust. "If we had it, it wouldn't be necessary to propose any of the actions in this petition," he said.

The goal of the emergency work this spring is to build reliability back into the system, he said. "It's a question of being prudently prepared for the summer. If nothing else happens, we should get through it OK. But the way you want to run a transmission system is to be prepared for the next worst thing that can happen."

http://timesargus.nybor.com/Story/6406.html

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-- (Dee360Degree@aol.com), April 16, 2000

Answers

What is a phase angle regulator?

What has failed on this job that dictates replacement rather than repair?

Is there a control problem involved?

-- Tom Beckner (becknert@erols.com), April 18, 2000.

Tom,

Good questions...hoping we can get more info on this. I'm tracking the story.

Best wishes, Dee

-- (Dee360Degree@aol.com), April 19, 2000.