PROVIDENCE -- When the Block Island Wind Farm starts today to ramp up to commercial operation, it won't be as simple as pressing a button or flipping a switch. Instead, after Deepwater Wind managers determine the time is right, an engineer in the company's Providence offices will give the go-ahead to a counterpart with turbine manufacturer General Electric who, from a remote location, will execute software to fully activate the first offshore wind farm in the United States.
Or actually not quite full activation. Because of an equipment mishap, one of the five six-megawatt turbines is down for repairs and isn't set to go online again until the end of this month at the earliest. Whether the four remaining turbines that were installed this fall in the waters off Block Island spin at full power is of course dependent on the wind and how strong it's blowing. But, with Deepwater today receiving the all-clear from the operator of the regional power grid, it now has permission to remove any constraints on the generating potential of the 30-megawatt wind farm and begin selling all the electricity pumped out by the towering wind turbines.
Making that happen could take a day or two, according to Deepwater CEO Jeffrey Grybowski. "It's not a moment. It's a process," he said earlier this week. The decision by Independent System Operator New England essentially concluded that operation of the wind farm could be integrated into the larger power system without causing disruption. It was the last remaining hurdle that Deepwater had to clear. In a unanimous vote last week, the Rhode Island Coastal Resources Management Council -- the lead permitting agency for the construction of the wind farm -- voted to conditionally sign off on the project.
The approval -- which came at the recommendation of ABS Consulting, an independent firm that monitored the progress of the project for the CRMC -- is contingent on receiving some final documents from Deepwater. "We don't anticipate any major issues," said CRMC executive director Grover Fugate.
Since the final blade was bolted into place in August, Deepwater has been running through a series of tests to make sure each of the turbines functions as expected, that the wind farm as a whole works without a hitch, and that power can be sent by underwater cables to substations on Block Island and on the mainland.
The turbines have been producing power for most of that time and delivering it into the electric grid. ISO-NE capped the amount at 12 megawatts -- equivalent to the total capacity of two of the Block Island turbines -- on the assumption that the power system could safely absorb that much during the testing phase. Deepwater wasn't paid for that power, but it will receive a credit equal to the market price when each kilowatt-hour was produced. The price will likely average several cents per kilowatt hour, well short of the price that Deepwater will be paid under a long-term power purchase contract it signed with National Grid, Rhode Island's dominant energy utility.
That price starts at 23.5 cents per kilowatt hour, but only remains in effect until Jan. 1 when it rises to 24.4 cents -- nearly three times the blended price National Grid currently pays for the rest of its power. An annual 3.5 percent escalator in the contract will see the price in the final year of the contract rise to 47.9 cents. Residents of Block Island, who pay some of the highest electric rates in the nation, will realize savings. And even with such a high price, the typical ratepayer on the mainland, according to National Grid, will see a bill increase of only about $1.07 per month in the first year of operation because the wind farm will produce a relatively small amount of power.
Ratepayers are also expected to catch a small break because of a clause in the contract that restricts how much Deepwater can get paid if the wind farm produces more than 40 percent of its capacity on an annual basis. Deepwater is now conservatively estimating that the wind farm's net capacity will be 47 percent. If that pans out, under the contract clause, the price per kilowatt hour could be a couple pennies cheaper. Operation of the wind farm will be closely watched by a host of parties. A wall-mounted monitor in Deepwater's offices gives real-time status updates on the turbines to company employees. On the morning that Grybowski spoke, the screen reported that two turbines were churning out power, two more were on but not spinning and the damaged one was shut down completely.
Deepwater has also hired Duke Energy Renewables to keep an eye on things around the clock from an operations center in Charlotte, N.C. Duke's main job will be liaising with ISO-NE and responding to any requests from the agency. General Electric will also be observing 24/7 from offices in Schenectady, N.Y. and Germany. Its focus will be on ensuring peak operation of the turbines. Workers can tweak systems online or send any of the 6 to 12 GE technicians based in the Quonset Business Park out by boat to service the wind farm.
It is those technicians who are getting ready to make repairs to Turbine 2, which was damaged when a drill bit was accidentally left inside a critical area. The bit was discovered when an alarm sounded, alerting GE that a foreign object was lodged within a 5-millimeter air gap in the turbine's direct-drive generator. By then, however, the bit had caused damage to an unspecified number of the 128 magnet modules that line the circular generator and are critical to producing energy. Those magnets can be replaced with relative ease, but they need to be shipped from a GE factory in France. The cost of the work is being covered by GE and won't impact ratepayers.
Apart from that setback, the series of tests on the turbines went smoothly, said Grybowski. At the time of the interview, he was anticipating approval from ISO-NE but wasn't planning anything special to mark the moment. Instead, he was focused on the decision and what it would mean for finally getting the wind farm up and running. "At that point, we'll be able to keep the wind farm in optimal operation," he said.