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Chugach reports on wind power usage Fire Island wind farm has produced about 50,000 megawatts of electricity; Chugach Electric used more than 90 percent of output Alan Bailey Petroleum News
After more than a year of obtaining some its power supplies from Cook Inlet Region Inc.’s Fire Island wind farm, offshore Anchorage, Southcentral utility Chugach Electric Association has now purchased about 50,000 megawatt hours of electricity from the wind farm, the utility told the Regulatory Commission of Alaska in a Jan. 30 status report.
The wind farm started outputting power at the end of August 2012, although formal commercial operation did not commence until Dec. 31 of that year. According to data presented to the commission by Chugach Electric, the power output from the farm was highest in January 2013 when the utility purchased 6,880 megawatts of electricity. The minimum monthly power purchase of 2,213 megawatt hours took place in July 2013. On average the wind farm generated about 30 percent of its theoretical maximum power output, the status report says.
Some curtailment However, Chugach Electric was unable to use all of the power that it purchased from Fire Island, with the utility declining the use of a total of 4,799 megawatt hours of the purchased power over the course of 2013. This curtailment of power from the wind farm mainly occurred as a consequence of an outage on the power transmission line that connects hydroelectric power on the Kenai Peninsula to Anchorage, the status report says. The consequent lack of access to hydropower, coupled with constraints on the gas-fired power generation facilities elsewhere on the power grid, limited Chugach Electric’s ability to accommodate the fluctuating Fire Island power output, thus causing the utility to have to decline some of that wind-generated power, the status report says.
Nevertheless, the resulting curtailment of less than 10 percent of Fire Island’s total output was well below the figure of 25 percent curtailment that had been assumed for the first year of the wind farm’s operation, the status report said.
The wind power that Chugach Electric used enabled the utility to register a total of 44,725 renewable energy credits — the utility is marketing these credits, with any proceeds from credit sales being used to reduce the cost of renewable electricity for the utility’s customers.
Accommodating fluctuations Prior to the startup of the wind farm in 2012 one major bone of contention in negotiations between CIRI and Alaska Railbelt utilities over purchase agreements for Fire Island power was the potential cost to the utilities of accommodating power that fluctuates with the wind strength. Power utilities need some spare generating capacity that can compensate dips in the wind power output. And that spare capacity costs money.
Railbelt utilities also expressed concern that the fluctuating wind power might cause power instability in the Railbelt power grid, although CIRI said that, with the output from Fire Island being small in comparison to total generation capacity on the grid, the impact of the power fluctuation from the wind farm would be negligible.
In its status report, Chugach Electric said that there is as yet no definitive verdict on this issue and that a further six to 12 months of data gathering, analysis and discussion will be required to determine the total impact of wind power usage on the grid. The status report says that, as part of this analysis, Chugach Electric has asked Anchorage utility Municipal Light & Power to provide information about any costs and impacts incurred by the utility as a result of the connection of Fire Island to the grid. Apparently, Municipal Light & Power has reported a preliminary review indicating an increase in the variability of the alternating current frequency on the grid since the wind farm went into operation.
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