Southwest village prepares to harness river in harmony with salmon

  • This graphic depicts Ocean Renewable Power Co.’s RivGen Power System. The first of potentially two RivGen units is being installed in the Kvichak River near the Village of Igiugig for a year of tests before. The community hopes to eventually use the RivGens as its primary power source. (Image/Courtesy/Ocean Renewable Power Co.)
  • Pieces of Ocean Renewable Power Co.’s disassembled 35 kilowatt RivGen Power System are barged across Iliamna Lake earlier this month for installation and a year of tests in the Kvichak River near the Village of Igiugig. (Photo/Courtesy/Ocean Renewable Power Co.)
  • Employees of Maine-based Ocean Renewable Power Co. pose in front of the company’s RivGen in-river generator being installed for the Village of Igiugig in Southwest Alaska. (Photo/Courtesy/Ocean Renewable Power Co.)

A small Southwest Alaska village is trying to integrate the power of an iconic Alaska river into its electric grid without interfering with the millions of salmon that rely on the same water.

The Village of Igiugig and Maine-based Ocean Renewable Power Co. are in the midst of a years-long partnership to refine and eventually utilize the company’s RivGen Power System generator in the Kvichak River.

The village of about 70 residents sits at the outlet of Iliamna Lake — Alaska’s largest — which feeds the Kvichak that flows another 50 or so miles before emptying into Bristol Bay. The clear waters of the system support some of the largest salmon runs on Earth. Somewhere between 3 million and 7 million sockeye and countless numbers of other salmon pass by Igiugig each year on their way upriver to spawning grounds in Iliamna’s myriad of tributaries.

However, the remote location that affords residents the opportunity to live in such a unique ecosystem also comes at a cost that many rural Alaskans are familiar with. Diesel fuel, which is the primary fuel source for power generation, averaged $5.85 cents per gallon last year in Igiugig, according figures compiled by the Alaska Energy Authority.

Acting Igiugig Administrator Karl Hill said that fuel is flown into the village in batches of about 3,000 gallons.

Those costs translate into residential electrical rates regularly in excess of 90 cents per kilowatt-hour, according to AEA, which the state then subsidizes through the Power Cost Equalization Program to a more manageable effective household rate of around 30 cents per kilowatt-hour. For comparison, recent electric rates in Anchorage were 18 to 20 cents per kilowatt-hour.

Power for businesses and most public buildings is not eligible for the PCE funding, which makes the cost of power a major impediment to economic growth across much of Alaska.

“We’re looking for any way we can to be more self-sufficient. To have the means to produce our own energy gives us that much more autonomy,” Hill said of the RivGen System.

A 35-kilowatt RivGen system, which is 12 feet tall and about 40 feet wide, landed in Igiugig June 6 after being barged across Cook Inlet from Homer to Williamsport, trucked 15 miles up the Williamsport Road to Pile Bay at the east end of Iliamna and finally loaded on a second barge for the final leg of the journey across the length of the massive lake.

That followed a May 23 order from the Federal Energy Regulatory Commission that approved a license for a pilot project to run two RivGen units in the Kvichak for 10 years.

Sen. Lisa Murkowski, who chairs the Senate Energy and Natural Resources Committee, has supported federal research and grant programs to advance small-scale renewable energy production and integration into small, isolated power grids.

According to her office, the Igiugig Village Council is the first Tribal entity in the country to gain federal approval for an in-river power project.

“I am so pleased this project will be able to move forward, reducing local diesel consumption and energy prices. Igiugig’s efforts are blazing a trail for marine renewable energy and microgrid solutions around the world — when we prove these technologies can work in rural Alaska, we are proving they can work just about anywhere else on the planet,” Murkowski said in a June 5 statement.

According to the FERC license, the single RivGen can produce power at an average annual cost of 78 cents per kilowatt-hour.

Company and village officials plan to install the RivGen soon and operate it for up to a year, ORPC project manager Monty Worthington said in an interview from Anchorage just a couple days before he was to leave the city for a summer of working on the system. The lengthy test should prove whether the system can handle its two biggest remaining challenges: big chunks of ice and tiny salmon.

Prior late-summer tests of a prototype bottom-dwelling generator indicated through five monitoring cameras that it can coexist with adult salmon and other fish, according to Worthington.

“A million-and-a-half sockeye went past the turbines and we saw no adverse impact,” he said.

Juvenile salmon, known as smolt, however, also pour out of Iliamna by the tens of millions each spring on their way to the ocean. The sheer numbers of them and the fact that they aren’t as adept as adults at avoiding hazards when in the strong main river current means how the smolt interact with the RivGen unit must be studied closely.

As it’s currently designed there is nothing to block fish or other objects from interacting with the RivGen. A large grate to deflect drifting wood or ice could be added, Worthington said, but a screen small enough to deflect smolt would almost certainly disrupt water flow and in-turn the efficiency of the unit.

The National Marine Fisheries Service recommended in comments to FERC that the twin-turbine generator be shut down for two weeks during the late May-early June peak of the smolt outmigration.

FERC officials are not requiring such a stipulation, but stressed in their order that the interaction be watched closely.

Worthington noted that like adult sockeye, the smolt usually stick closer to shore and the surface of the river when on the move. He also compared the leading edge of the five-foot diameter open turbine to a baseball bat, meaning any little fish that swim through it wont get cut by the unit.

“They’re better at avoiding than we assume they are and also they just get pushed out of the way by the pressure wave on the front of these (turbines),” Worthington said.

Still, a biologist will be on-site continuously during the smolt season to monitor any impacts the RivGen might have on them.

“Certainly, if we find out that smolt are getting injured by our device we won’t be operating at that time of year; it’s a no-brainer,” he added.

ORPC officials also feel that they will be able to work around ice flows emitting from Iliamna Lake each spring, though the upcoming winter will be the first that the RivGen is in the water.

The Kvichak itself is a fairly quick, deep river near the outlet of the lake so it rarely freezes over and the large lake provides unusually stable flows when compared against other large Alaska rivers. Additionally, the chosen installation site is about 15 feet deep, Worthington said, so ice sheets should drift harmlessly over the 12-foot tall RivGen. The site is also immediately downriver from a large shoal that should deflect large chunks of ice.

Still, ever more common mid-winter thaws can send ice downriver at unpredictable times and ice jams in a shallow, braided section below the RivGen site could complicate matters, he acknowledged.

Keeping the unit in the water and operating year-round is paramount to maximizing the project’s efficiency and driving down its per-kilowatt cost.

“It’s a big experiment and we recognize (ice) is probably one of the riskier aspects of the project, but it’s also such an important one,” Worthington said.

If it is damaged ORPC will need to devise ways to protect it or pull it from the water easier, he said.

If the yearlong test proves successful, the plan is to install a second unit; combined, the two could produce up to 70 kilowatts of electricity and mostly get Igiugig off of diesel-fired power. The village’s powerhouse has 40 kilowatts of generation capacity, according to the FERC license.

Village Administrator Hill said the village has plans to purchase large batteries for power storage and is also working with micro-grid developers to better integrate existing small wind turbines into their power system as well.

Completely shutting off diesel generation is rarely feasible, as it is needed to mitigate fluctuations in power from variable renewable sources and make up for sudden spikes in demand that — particularly in small isolated communities — can come from a single residence.

ORPC believes two fully operable RivGens with the requisite grid upgrades should allow Igiugig to limit its cumulative diesel generation to about four weeks per year, Worthington said.

The first unit and several years of shipping, testing and monitoring has been paid in part by federal Department of Energy grants totaling $2.3 million. Those grants required equal private matches for a total project cost of $4.6 million, according to Worthington, who acknowledged it’s a high price for a small village endeavor.

“I think they key is this is all a first-build,” he said. “A lot of our construction costs are easily double what even a second unit would be because to build the turbines we had to build molds for them and everything’s sort of like that.”

He estimated a second RivGen would cost about $1 million, with costs gradually shrinking for subsequent units.

The technology could also eventually be scaled and applied to other river villages and is very applicable to shallow tidal sites near costal communities, he added.

Even with another year or two of refinement, Igiugig’s hydrokinetic power project has already been years in the making.

ORPC officials first visited the village in 2011 after initially investigating the prospect of testing their technology at the community of Nenana on the banks of the Tanana River south of Fairbanks. Worthington said the appeal of Nenana was that it’s right on the Parks Highway, which would’ve allowed the company to avoid all of the logistical challenges inherent to working in remote Alaska.

However, the glacially muddied Tanana didn’t prove cooperative, he said. The dark water made it difficult to monitor fish, debris and even confirm the composition of the river bottom.

Meanwhile, Igiugig leaders were starting to seek renewable energy prospects of their own through Alaska Energy Authority programs.

“It was clear they really wanted to partner with technology providers to try to do this,” Worthington recalled. “It was an accepting community.”

Prototype tests in subsequent years led to development of the latest commercial RivGen model.

Hill said the work with ORPC has indeed been a long process, but one that’s necessary to pioneer new technology.

“We have a very active village and council — very progressive,” Hill said.

“Living next to this wonderful source of power that flows past us 24 hours a day…it’s pretty obvious that if we can harness some of that energy and not harm the salmon and some of the other fish in our area it’s definitely something worthwhile.”

Elwood Brehmer can be reached at [email protected].

Updated: 
06/12/2019 - 9:15am

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