Power play: Shumlin argues against wind curtailment 

Earlier this month, while Vermonters were broiling in a heat wave, the entity that oversees the regional electric grid directed Green Mountain Power Corp. to cut back on the amount of power its Lowell wind turbines were generating while also firing up its standby diesel generators.

Scale back on the clean wind power in favor of smelly diesel? Both Green Mountain Power and Gov. Peter Shumlin are objecting to what they portray as a head-scratching, short-sighted move.

In a letter to ISO-New England President Gordon van Welie, Shumlin challenged whether ISO’s planning assumptions align with reality and whether the organization has sufficiently taken into account the burst of renewable energy being constructed.

“I urge ISO-NE to consider whether … it could do more to integrate and fully utilize renewable resources into its grid operations, including during times of peak demand where use of other more expensive and dirtier resources may be avoided,” Shumlin said in the letter.

ISO-New England hasn’t written back to Shumlin yet, spokeswoman Marcia Blomberg said, but it should have come as no surprise to Green Mountain Power or the state that the utility would be asked to curtail power from Lowell.

That’s because the transmission capacity in the Northeast Kingdom where Lowell is located is not strong enough to handle all the power from the new turbines, Blomberg said. Because of that, ISO required Green Mountain Power when it planned the 21 Lowell turbines to install a condenser to modulate the influx of power. The $10 million condenser is under construction and until it’s operating, ISO will have to occasionally curtail power from Lowell, Blomberg said.

When Green Mountain Power completes the condenser, scheduled for later this year, that will likely solve the need to have power at Lowell curtailed, she said.

Green Mountain Power objected to installing a condenser, but agrees that it should solve the curtailment, spokeswoman Dorothy Schnure said.

ISO directed Green Mountain Power to curtail the output of its Lowell turbines from 45 megawatts to 15-20 megawatts during the mid-July heat wave, Schnure said.

The same day, ISO directed Green Mountain Power to use several jet-fuel and diesel generators that are on standby for peak demand, Schnure said. Those sources are some of the most expensive and highly carbon-emitting energy to run, she said.

Those of you sitting at home might be wondering how all of this bodes for the future of renewable energy projects. As in, will they be worth building?

The Lowell wind project is still economically worthwhile, Schnure said, even with the forced curtailing of power.

Kerrick Johnson, vice president of Vermont Electric Power Co. (VELCO), said no conclusions should be drawn about renewable energy projects based on this case. “It’s very site specific,” he said.

What about the proposed Seneca Mountain wind project in Brighton and environs? If it’s built, it would be generating wind power in the same region, into the same underdeveloped transmission system as Lowell.

VELCO President Chris Dutton earlier this year, in a letter to the Lyndonville Electric Department, advised, “Additional generation in this area will almost certainly require additional transmission grid enforcements.”

Johnson said the Seneca Mountain developer is in the midst of studying for ISO-New England what impact that project would have on the transmission grid. When that’s done, developer Eolian Renewable Energy will have the same kind of information Green Mountain Power had when it built Lowell about what ISO will require in the way of upgrading the grid.

Meanwhile, what Shumlin and Green Mountain Power seem to be saying to ISO-New England is that it needs to change the way it thinks when it comes to forecasting electric generation to better incorporate renewable energy.

“Vermont has a clear preference for renewable resources and would have preferred that the local renewable energy produced by this utility-owned resource had been used to meet regional power needs in the Northeast Kingdom and surrounding communities where homes and businesses were also experiencing a period of high demand last week,” Shumlin said in his letter to ISO-New England.

For its part, ISO is neutral on energy sources, spokeswoman Ellen Foley said, not favoring one over another. But if there is a form of generation that has not complied with required upgrades, that source is likely to be the first to be ordered to curtail power generation when there’s a risk of overload.

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Related Links

PDF: Gov. Peter Shumlin’s letter to ISO New England