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Eklutna power station progresses; needs transition in early 2015
After several years of planning, engineering and construction, much of Matanuska Electric Association’s new gas-fired power generation station at Eklutna, north of Anchorage, is now in place, Joe Griffith, the utility’s general manager, told the Regulatory Commission of Alaska on Aug. 13. But with full operation of the new power generation facility not now expected until March 1, the commissioners expressed concern about the need for a transition plan for the period after MEA’s power supply contract with Chugach Electric Association terminates on Dec. 31.
Currently Matanuska Electric, or MEA, the electricity utility for Alaska’s Matanuska-Susitna Valley, buys power from Anchorage-based Chugach Electric: The new Eklutna plant is designed to replace the Chugach Electric supply, starting on Jan. 1.
Griffith said that he expects four to six of the facility’s 10 power generation units to be operational by Dec. 31, with the remaining units coming on line during the following eight weeks or so. Commission Chairman Robert Picket asked if MEA has a “plan B” to cover the period after the termination of the Chugach Electric contract and before full operation of the Eklutna plant.
“The ratepayers in the MEA service area have a right to expect that they’re going to have a reliable service on Jan. 1, 2015,” Picket said.
Griffith said that, although MEA does not yet have a signed agreement for power supplies during that transitional period, he anticipated forming an agreement with Chugach Electric and Municipal Light & Power within the next couple of months, especially as MEA has already contracted natural gas supplies, some of which the other utilities could presumably use.
“We have gas and could put it through their machines,” he said.
Equipment in place Griffith said that all of the equipment in the main powerhouse at Eklutna is in place and mostly plumbed in, and that testing and commissioning has started. The manufacturer of the engines that the facility uses discovered a problem with some of the engine valve assembly castings when installing some extra temperature sensors that MEA had requested - it may be the end of October before it is possible to start testing the first of the engines, Griffith said.
And MEA anticipates completing construction of the main transmission line north from the power station by end-September or mid-October, although there is still a court case in progress involving a challenge by a local resident to the transmission-line route.
Meantime, various tank systems that the power plant will use have been installed, including two 500,000-gallon tanks for holding diesel fuel - the plant’s reciprocating engines are dual fuel, able to run equally well on gas or diesel, thus enabling the use of diesel fuel should there be an interruption in gas supplies.
Apparently MEA and Enstar Natural Gas Co. are in the final stages of completing an agreement for the transportation by Enstar of gas to the plant through an Enstar gas transmission line that runs close to the plant.
Challenging transition The transition for MEA from a relatively small electricity distribution company to a vertically integrated company, handling the entire power supply process through power generation, transmission and distribution, is proving something of a challenge, Griffith said.
“That’s no small undertaking for a small distribution company like we are,” he said, commenting on the complexities of fuel management for the power generation, the need to upgrade the utility’s power dispatch system, and the need to train the utility’s dispatchers.
And with the MEA dispatchers not being experienced in dispatching power generation, MEA is negotiating with Chugach Electric, to have Chugach provide dispatch services for the Eklutna plant, at least initially. MEA is constructing a high-speed communications loop between the Eklutna plant and other dispatch centers. Chugach Electric could simply dispatch the Eklutna power as an additional generation center, Griffith explained.
Griffith said that, in the longer term, he would like to see a single electricity load balancing authority, dispatching power for the entire southern part of the Railbelt power grid, as far north as Healy in the Alaska Range. Such an arrangement would eliminate the complex interfaces between existing load balancing regions while also enabling the optimum use of generating facilities around the grid, he said.
Goes back to 2004 Griffith told the commission that the story of the Eklutna Generating Station goes back to 2004, when Chugach Electric notified MEA that Chugach would stop supplying MEA with power in 10 years’ time. That set the date of Jan. 1, 2015, for MEA to start using some alternative power source.
Following several studies and after conversations with other utilities, in 2009 MEA ramped up its efforts to establish a new power supply arrangement, Griffith said. He said that, at that time, he investigated the possibility of finding some way of using existing power generation assets, while also taking a hard look at the Cook Inlet fuel supply situation and the configuration of the gas pipeline infrastructure in the Cook Inlet region. It was also necessary to consider the electricity load characteristics of both MEA’s region and other regions in the Railbelt, he said.
“That led us to the decision to buy 10 17-megawatt Wartsila reciprocating engines, with dual fuel capability, both natural gas and diesel,” Griffith said.
Load following capability A particular advantage of the reciprocating engines, as distinct from more typical gas turbines, is that the engines can be throttled between low and high power outputs with little change in power efficiency, thus enabling the engines to readily follow the varying electrical load that MEA may have to support. In fact, the new power plant will prove particularly effective in support of load following on the Railbelt grid - Griffith confirmed that MEA has been conducting discussions with Golden Valley Electric Association over the possibility of the Eklutna plant providing load following services, in support of the variable power output from Golden Valley’s Eva Creek wind farm.
Convenient site The chosen site for the Eklutna Generation Station is particularly convenient, being adjacent a major highway, the railroad and one of Enstar’s main gas transmission lines, Griffith said. And, despite some concerns over possible problems with injecting Eklutna power into the Railbelt grid at that particular location, a study has indicated that the location of the plant presents no problem, he said.
After running into difficulties with the original contractor hired for managing the engineering and construction of the Eklutna plant, MEA itself took over management of the project, an arrangement that Griffith said has proved successful. Griffith said that he anticipates the total cost of the project coming in at around $304 million, with a 10 percent contingency. MEA’s customers will likely see a 15 to 20 percent rise in their electricity rates when the plant comes on line, in particular because of the price that MEA will pay for its gas supplies, he said.
- Alan Bailey
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