Energy storage has been used to serve multifarious grid needs, but salmon-induced demand mitigation may be a new one.
The remote town of Cordova, Alaska, located on the coast between Anchorage and Juneau, inaugurated its first utility-scale lithium-ion system last week to manage the peaks when the seasonal salmon catch comes in and needs to be processed.
Local power provider Cordova Electric Cooperative runs the town's isolated grid, powered by 7.25 megawatts of run-of-river hydropower supplemented by diesel generation, according to a detailed blog post by CEO Clay Koplin, who also serves as mayor.
The diesel represented a pain point for the cooperative, both because the group subscribes to "the principles of sustainability, resilience and holistic thinking," and because diesel generation can cost up to 10 times as much as local hydropower production.
Still, when the salmon come down the nearby Copper River and the fishing boats bring in the wild, red-fleshed catch, CEC needs that fossil-fueled power to meet the demand for processing. Just as in the winter, when the rivers freeze over, the diesel saves the day.
The newly installed 1-megawatt/1-megawatt-hour system from Saft, with power electronics from ABB, is designed to help the utility use less diesel and more renewable power.
"We are marching toward a smart grid, smart city architecture, and this is another step," Koplin said in an interview.
The containerized battery system sped up installation in the remote environment. (Image credit: Rob Roys/ABB)
Stabilize the grid, without waste
When the local grid runs on hydropower alone, that resource has to perform grid-balancing duties like frequency regulation.
In practical terms that means deflecting some of the river flow to create a buffer in case demand spikes suddenly. This practice sacrifices about 500 kilowatts of capacity to support frequency; the deflected water doesn't come back.
As far as various tools go, fast-acting lithium-ion batteries are innately well suited to managing the moment-by-moment fluctuations of the grid, just as salmon are innately adept at migrating back up rivers to spawn where they once hatched.
When the salmon industry ramps up and electrical demand starts to outpace hydro generation, CEC flips on a diesel generator with a minimum output of 400 kilowatts. That cuts further into hydropower production. During these times, the co-op can sacrifice up to a megawatt of hydropower capacity to allow for these other functions.
The battery will now take on that fast-ramping duty, allowing the co-op to save the diesel genset for when the battery runs low on charge.
Built to last
Grid resilience takes on special meaning in Cordova, where there is no bigger electric grid to rely on if the local system goes down.
The town doesn't even connect to a broader transportation network — it's accessible from afar by ship or airplane.
That made installing a storage system more logistically difficult than typical jobs. It also drove CEC to pick established players with a track record operating in tough environments, Koplin wrote.
ABB and Saft both descend from century-old corporate lineages. French oil and gas major Total acquired battery maker Saft in 2016 for $1.1 billion, meaning it has a particularly large balance sheet standing behind it. The suppliers provided a modular, shippable system that shortened on-site installation.
Grid resilience is a trendy topic, but the electric industry is still figuring out how to define and act on it. The early adopters willing to move forward with resilient microgrid systems today tend to be ones with extreme needs that make the storage value proposition abundantly clear. Hence Eversource New Hampshire's proposed battery to deliver backup power to a rural town beset by blackouts.
Reliability in a harsh environment already drove CEC to put 100 percent of its power lines underground, Koplin noted.
The heightened cost of imported fossil fuels also makes the business case for cleantech alternatives more compelling in places like Cordova, and mirrored in Hawaii's push to replace diesel generation with solar-plus-storage.