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When your largest single source of generation is located in a town called North Pole, Alaska, operating under extreme weather conditions plays a major role in planning, maintenance and day-to-day operations.
It also means designing and building for contingencies to ensure that members have the electricity they need when they need it.
“Our summers are pretty mild, and the load on our system is quite low, but Golden Valley Electric Association maintains a lot of generation,” says John Kelly, gas turbine plant manager at the Fairbanks-based co-op.
From April through October, GVEA has excess capacity to meet the needs of its 100,000 residents and back up the demand of four military installations, the University of Alaska-Fairbanks and two large-scale mining operations.
“From October through the end of March, conditions change drastically, as we roll through the dark of winter with temperatures reaching 40 to 60 degrees below zero at times,” Kelly says. “Our system loads are significantly higher than in the summer due to demand for light and heating.”
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Even with the 138-kilovolt Alaska Intertie, which connects Interior Alaska with the southern utilities located in Homer, Anchorage and Matanuska, GVEA considers it essential to be able to meet all demand locally. So the co-op maintains 350 megawatts of generation from a dozen sources including diesel and naphtha, coal, hydropower, solar, wind and battery storage.
“We have a lot of redundant generation due to the fact that letting the lights go out and the power stop is not an option for our 36,000 members,” Kelly says. “Winter weather is potentially life-threatening, so it is absolutely paramount that we have the ability to generate all of our power locally.”
Another facet that GVEA gives special attention to is maintenance and operations, with hardening applied to even the most common components.
“Over the past 10 years, we’ve been replacing oil- and gas-filled circuit breakers with vacuum circuit breakers on our 72-kilovolt system,” says Nathan Minnema, GVEA’s senior engineer. “That technology is now available for replacing circuit breakers on our 138-kV system, and we will install the first three this year.”
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The breakers provide switching points and allow for isolation of portions of the system when faults occur, preventing damage to other equipment.
To operate properly, oil- and gas-filled breakers must be constantly heated to maintain proper viscosity. Each of them requires about 5,000 watts of heating load nonstop during six months of harsh seasonal weather. The switch to vacuum technology eliminates the need for the heaters and contributes to a more robust and resilient system.
“If we had a heater fail on a gas or oil breaker, we’d have more risk at cold temperature of failures,” Minnema says. “Switching to the vacuum technology reduces the likelihood of issues popping up.”
The co-op has also upgraded its outage management and metering systems, says Naomi Knight, GVEA’s environmental officer.
“We're doing a lot of installations of digital fault recorders to identify locations that are prone to issues,” she says. “That information can be used to improve crew dispatch, particularly to areas that are difficult to reach.”
Fault tracking and detection initiatives begun about eight years ago as part of a plan to improve reliability and reduce outage times in areas where track vehicles and snow machines are the most reliable means of reaching trouble sites.
GVEA is part of the Railbelt, an isolated grid stretching from Homer on the southern coast of Alaska, running north through Anchorage and Wasilla and ending in the interior. GVEA is working with the other Railbelt utilities on generation strategies designed to meet future needs, says Kelly, noting that regulatory and environmental issues are major concerns.
“What’s best for the Railbelt?” he says. “Not necessarily today, but let’s look out there 20 to 50 years from now.”
GVEA grew steadily over the past 75 years based mainly on coal-based generation.
“Coal is our cheapest source of power, and it also is our most abundant source of fuel, which is a really, really big deal to us,” says Kelly. “Our coal plants are literally built on top of a coal pile, meaning we have probably over 100 years of fuel reserve.”
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Hydroelectric power offers promise, he says, but co-ops are weighing development costs against operating concerns, including state and federal policy.
“We don’t feel like we have to own and operate all of our generation,” says Meadow Bailey, the co-op’s director of external and public affairs. “We’re looking more toward the long-term interests of our members and weighing the benefits of developing our own generation assets or purchasing power from contracted sources. This gives us more opportunities to balance costs against other considerations like environmental impact or future regional development.”
The co-op consults neighboring utilities on projects that could enhance grid resilience and spread development costs over several entities. Those not only include modernization of the Railbelt but also buildout of roads and other infrastructure and pipelines clearing the way for more utilization of natural gas.
“Alaska’s federal delegation advocates for infrastructure funding for this state, because we do not have existing infrastructure,” Bailey says. “While the interstate system was being built in the Lower 48 states, Alaska was just becoming a state. Alaska lags behind other states in infrastructure development, including the electric grid. And there’s so much potential here, from natural resource development, tourism and other types of economic development.”
GVEA was one of the first utilities in the nation to deploy a battery energy storage system, or BESS, to improve reliability. At the time, it was the world’s most powerful battery, earning a Guinness World Record in 2003. Now more than 20 years old, the large nickel-cadmium battery pack kicks in when other generation fails to keep supply flowing while operators switch circuits to bring other generation online.
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The system was activated 60 times in 2021 and is typically used for no more than 15 minutes at a time.
“It needs ideally three days to recharge between discharges, so it’s not a battery technology or system that’s designed for increased cycling or frequent use to balance renewables,” says Minnema, adding that the co-op is considering upgrading to lithium-ion technology. “We’re currently evaluating the pros and cons of whether to continue investing in our existing BESS or making a larger capital investment.”
The co-op constructed and began to receive power from the 25-MW Eva Creek Wind Farm in 2012, the first such installation by any Railbelt utility. It remains the largest wind project in Alaska.
“GVEA has always focused on meeting the needs of our members. Historically, that involved generating electricity regardless of extreme conditions and making sure contingencies were always in place,” Bailey says. “Looking forward, our success is tied to cooperation with the other Alaska Railbelt utilities. We need large-scale solutions and infrastructure upgrades that benefit residents from Homer to Fairbanks. That is our focus.”