JAY – Any day now, a gray cube the size of a dump truck will shiver into life along the eastern shoulder of North Jay Mountain.
When it does, the electricity generated by Green Mountain Power’s 21 wind turbines on Lowell Mountain will flow more evenly and generously – a full 63 megawatts’ worth – across the northern Vermont grid.
The $10.5 million gray cube will have “conditioned” that power.
Is that all we need to know? Possibly.
With the advent of remote, fiber-optic switching and maintenance, our electrical connections have become impersonal, even robotic.
Should we care? You decide.
One recent day, the substation in this corner of the Northeast Kingdom was swarming with people eager to explain the impending convergence of wind power, wiring, plumbing, refrigeration, hydraulics, smart-meters, software and battery back-up.
A visitor arrived at the barn-like building only half-prepared. He wore a regulation hardhat, safety goggles and durable boots. He dressed sensibly for the drafty, barely-above-freezing working conditions inside.
He had been warned that the elephantine gear in question bore a boring name – a “synchronous condenser” – and it would be far from photogenic.
Even more troubling, he was warned that the condenser’s subtler virtues would be hard to explain.
His advisers were correct.
Background reading helped but could not remedy a decades-long neglect of elementary physics.
Who knew that electricity posed more problems than spikes, dips, shocks and outages?
Who knew that phantom elements of electricity race back and forth on power lines in predictable (but still, somehow, alarming) waves of “effective” (working) power, and more mysterious “reactive” (harmonizing) power? And that these waves must be coaxed into more predictable rhythms before they reach a three-prong outlet?
Who suspected that electromagnetic forces could be stirred and steadied with something akin to an industrial-age flywheel?
Luckily, this stuff is common knowledge among those who deliver the goods.
Unexpectedly, the cube and its plug-ins brim with a hybrid appeal of steam- and cyber-punk.
The condenser’s form invites an examination of its function.
Its recent arrival deserves a little history.
Last summer, six months after the Lowell Mountain turbines (collectively termed Kingdom Community Wind) churned their first kilowatts, regional demand for electricity peaked.
New England ISO, the organization that fine-tunes our transmission lines, ordered Green Mountain Power – Vermont’s largest electric utility – to curtail production at the facility and to fire up auxiliary, fossil-fuel generators elsewhere in the state.
It was determined that a bottleneck of sorts had developed at the Jay substation, where an ample flush of hydro power already streamed south from Quebec.
The wind turbines’ connection to VELCO (the statewide transmission utility) and to Vermont Electric Cooperative (a distribution utility, like Green Mountain) was deemed insufficiently reliable, even risky.
Green Mountain Power complied for the good of the greater grid, stilling many of the turbines.
And it fast-tracked the installation of the synchronous condenser.
Popular analysis of the curtailment emphasized the remote location of the King Community Wind project: Its distance and scale are far removed from concentrations of demand, even with the power-hungry ski business at nearby Jay Peak resort.
But an “overload” at the Jay substation didn’t drive the need to tweak its circuits, said Mike Taylor, a marketing project manager for Mansfield, Ohio-based Hyundai Ideal Electric Co.
His company’s “synch” condensers, including the new one in Jay, remedy large wind turbines’ more subtle shortcoming: their innate inability to add to transmission lines the right amounts of reactive (voltage-stabilizing) power, measured in “vars.”
Taylor waded deeper into the explanation, bidding us to follow.
Wind turbines typically use induction generators, which are lighter in weight than their synchronous cousins, Taylor said. The latter sort are the dynamos-of-choice for large, earthbound generating plants.
Synchronous generators, as the name suggests, do a much better job keeping a healthy pulse in the lines.
Synchronous condensers (and motors) share the virtue of adding reactive power to a system – a phenomenon vaguely like the stabilizing back-pressure in a well-tuned automotive exhaust pipe.
Taylor sidestepped that analogy, concluding: “It’s just the nature of the beast. Those turbines require vars from the system; somebody needs to supply those vars.”
Then, thankfully, he steered the discussion toward hardware.
• Inside and out, the big, gray cube is a dead-ringer for a power generator or electric motor.
• Its limousine-length rotor, its electromagnets and its symmetrical windings of wire are familiar innards to those of us who have pried apart electric fans and/or battery-powered toy cars.
• Unlike a consumer-grade motor, the 62-ton Hyundai Ideal model requires an 800-horsepower kick-start from an attached “pony” motor.
Geno Balestra, the Green Mountain Power project coordinator, took time for a hands-on tour – provided that visitors maintained a hands-off policy.
He began in the on-site trailer that serves as the project’s main office.
On one wall, a “lock-out” list of circuits drove home a formula for safety: Power enters the substation at a strapping 46,000 volts and steps down only gradually below 480 volts (the potency of household current is a mere 110).
When a switch is off, a technician’s photo-ID and two padlocks warrant it to be inert.
Balestra continued his tour outside, where the wind whistled through a polished matrix of transformers and breakers.
He traced the passage of the VELCO main line to where it hooks up to the Vermont Electric Cooperative substation, and to the new splice that ties them both, via the condenser, to the Lowell Mountain turbines.
After a glance at the seemingly redundant chiller units, we moved inside, where Balestra has been choreographing the progress of about 15 busy, tool-laden technicians.
Some of the workers toted laptops, porting them into banks of winking microprocessors. Others tightened fist-sized bolts with wrist-thick wrenches.
Most of them circled periodically past the single propane heater.
Balestra urged visitors to conform to the traffic’s prevailing steady, cautious pace. So far, not a single accident had taken place on this floor.
Seen from a catwalk, the crews’ orbits of work coalesced into pockets of intense focus, even beauty: the bright blue tangle of hydraulic pipes; the motley array of oil rags; the orderly, vascular routing of cable.
Clash of symbols
The tableau of concerted labor also served as a reminder that large-scale infusions of power from wind – or large-scale industries of any sort – are rarely “plug-and-play:” Our grid must be coddled as it matures.
Will the condenser help resolve ongoing controversies regarding turbine noise and ridge-top development?
Maybe – if, behind the scenes, it can convince skeptics that the Kingdom Community turbines finally are pulling their weight as advertised.
More certainly, the arrival of the synchronous condenser on a 120-foot-long trailer (relieved of half its 12 axles to make the final turn into the substation) signaled one utility’s confidence that wind power remains an important piece of the renewable-energy puzzle.
But the big gray cube serves poorly as a symbol.
The condenser’s role is in the background, said Josh Castonguay, Green Mountain Power’s director of generation and renewable innovation.
In mathematical terms, its contribution is the square root of minus 1, which, he pointed out “is an imaginary number.”
By some definitions, Castonguay added, the rotor will be doing no “real” work at all.
He offered to elaborate on the trigonometry of it all. The visitor sheepishly opted for plain English.
“Northern Vermont’s grid has been right on the edge for years, in terms of needing more support,” Castonguay said. “The condenser is there to hold the voltage rock-steady.”
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