August 4, 2013

Inadequate transmission lines keeping some Maine wind power off the grid

Ratepayers will likely bear the cost of future upgrades to fix the problem, which could get worse.

By Tux Turkel
Staff Writer

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First Wind’s Stetson wind farm, in Washington County near Danforth, is among the turbine projects in New England that sometimes can’t send their power into the grid because local transmission lines are too weak. The problem is expected to become worse as more wind farms are built, and the regional grid operator is exploring ways to improve the situation.

2010 Maine Sunday Telegram file photo/Gregory Rec

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But the Maine Power Reliablity Project wasn't designed to hook up individual power plants through smaller, 115-kilovolt lines, according to John Carroll, a CMP spokesman.

"The MPRP is the highway and those are access roads to the highway," he said. "We did improve access, but it's a long way to the western mountains, where you're going to have those constraints."

Conventional power plants that hook into the grid are required to design their connections to meet certain technical standards for voltage and thermal performance. These standards are meant to keep lines from becoming too hot or electrically unstable. But federal utility regulators have allowed wind projects to connect with only minimum standards.

"However," the ISO paper continues, "this standard does not ensure that the resource will be able to put its full output on the grid. Generators that do not fund additional elective upgrades to enhance their access to the transmission system, or connect to a relatively weak area of the system, are at a higher risk of being curtailed."

So far, every wind generator that has hooked up to CMP's system has chosen to meet only the minimum standards, Carroll said.

Compounding the problem for wind is the way ISO-New England schedules power plant output for the next day, based on a generator's price and ability to run. Wind farms often can't predict how much power they can produce the next day. And even if they do have power to offer, they may not be called on by the ISO, because firm commitments from natural gas, hydro and other plants already are in the queue.

Power plants don't get paid when they aren't selling energy, according to the ISO. The exception is plants that receive capacity payments, essentially a stipend for being available for emergencies.

But even with curtailment, wind companies and their investors can still make money. That's because wind qualifies for above-average rates, long-term power contracts and production tax credits meant to encourage renewable energy. Some projects also got millions of dollars in federal stimulus money during the recession, and investors received tax benefits.


To critics of wind power in Maine, curtailments are just another reason to limit the number of new projects.

"In the last few years, $1 billion has been spent on wind, and it doesn't make a material contribution to the grid," said Chris O'Neil, a lawyer who represents Friends of Maine's Mountains. "If another $1 billion is spent, how much worse will congestion be, and how much more will that increase transmission rates?"

O'Neil said that locating wind projects on remote mountains, far from cities, "is a recipe for failure."

Curtailment could become a bigger issue as more wind is placed in the system, First Wind acknowledges.

First Wind had 185 megawatts of installed capacity operating in Maine last year, enough to power 66,000 homes. The company is planning the biggest wind farm in New England, a 186-megawatt project around Bingham that will include 62 turbines. Last week, it received approval to build a 54-megawatt project next to its Bull Hill Wind farm at Township 16, in Hancock County.

First Wind had 20 percent of its power curtailed last year at its Bull Hill, Stetson I and II and Rollins projects, according to John Lamontagne, a company spokesman. At least half of that was due to CMP's construction, he noted, and that won't be an ongoing issue.

First Wind also is spending money to upgrade a transmission line in Lincoln, Lamontagne said. That will help projects in eastern Maine but not solve the overall problem.

"While developers can improve the transmission system on a project-by-project basis, we believe the region is in a better position to make upgrades that will benefit the whole region by allowing more wind penetration," he said.

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