Igiugig will test RivGen hydropower through the winter

The RivGen operating in the Kvichak River in 2015. (Image credit Ocean Renewable Power Company)

In the Yup’ik language, Igiugig’s name means “like the throat that swallows water.” The Bristol Bay village of about 70 people sits at the head of the mighty Kvichak River. The turquoise waters rush out of Iliamna Lake and past the village with such force that it rarely freezes over, even in the winter. The community is hoping to harness that power in its ongoing quest for independence from diesel.

The high price of diesel motivates the community to seek alternatives. Igiugig flies the fuel for its generators over miles of tundra. That drives the cost up to about $7 per gallon.

For several years, it has been the test site for a hydropower project. In June, the project got a new lifeline—a $2.3 million award from the U.S. Department of Energy to continue as the test site for the RivGen Power System designed by the Ocean Renewable Power Company of Maine.

“The unique thing about the RivGen device and hydrokinetic energy in general, as compared to other renewables, is that it’s very predictable in how much power it will produce in either a tidal or river site,” said Monty Worthington is the ORPC Director of project development in Alaska. “In a river site, not only is it predictable, but it will always continue to produce power unless you have some kind of equipment failure. And so you can really look to hydrokinetics as a baseload energy resource that really, hopefully, eventually moves the diesel to more of a backup source.”

The RivGen turbine is a hydrokinetic system designed for rivers and shallow tidal waters in remote communities. ORPC first tested versions of the system in Igiugig in 2014 and 2015. The project stalled briefly during a gap in the funding. With the recent monetary support from the Department of Energy, ORPC has developed a new RivGen model.

“Over the next two and a half months, we’ll be fully assembling the RivGen device in Maine, making sure everything fits, doing all of our alignment, things like that. And then we will disassemble it and ship it to Anchorage after that,” said Worthington.

From Anchorage, the plan is to test the system in Nikiski at a “virtual river” test site and transport the RivGen to Igiugig by the end of May. The RivGen will deploy for two months during the summer and be removed from the river for maintenance in the fall. Then it faces the big test. ORCP plans to test the device in the Kvichak over the winter for the first time.

“The lake ice does go out in the spring, and that is probably the single biggest risk to the device, that and what we call frazil ice accumulating on the device in really cold periods if the river’s open,” said Worthington. “This is an important aspect of the project. If we had to take it out for the winter every year. It certainly wouldn’t be as economically attractive as if we can leave it in throughout the course of the year.”

Environmental monitoring is another key component of this testing period. Protecting the Kvichak River’s prodigious sockeye salmon run is a top priority for all involved in the project. The river’s clear water allows video cameras on the device to document how it interacts with fish. In 2014 and 2015, it found no negative effects on adult salmon returning to spawn. If the device is going to stay in the river all year, it also needs to be safe for young salmon travelling downstream in the spring.

“Larger fish just tend to just avoid the device,” explained Worthington. “Sometimes smaller fish do pass through the turbine while it’s operating, but we saw no negative interactions, and it’s partly because the size of the fish is so small relative to the diameter of our foil that they just get pushed out of the way by the pressure wave. And we think with smolt, they are more likely to interact with the device. And we need to document both in front of and behind the turbine their behavior and understand if they’ve had any certain negative effect from interacting with the device.”

The DOE-funded portion of the project concludes in the summer of 2020. Depending on the results, ORPC and Igiugig could discuss the possibility of the village continuing to use the RivGen.

More than $4 million state and federal dollars have gone into developing this RivGen system. But Worthington said the design phase is full of onetime costs, such as building molds. He is optimistic that the RivGen system could be a cost-effective and environmentally sustainable alternative for rural communities worldwide.

Igiugig is working on several alternative energy projects involving long-term energy storage, wind power and solar power. Some of those, like the RivGen, are pilot programs for emerging technologies. It is a long road to independence from diesel as the village works through rounds prototypes, studies and funding options.

Karl Hill, the acting village administrator, explained that operating as a test site is a part of the village’s commitment to finding sustainable energy sources.

He said, “We are really open to new technology, and we know that none of this is going to be a slam dunk. But we’re willing to work with some of the companies that we work with because they are easy to work with. They do take into consideration advice that we have on fish, and whatnot, [and] river conditions. It is still kind of in its infancy, but we’re excited about it, and we don’t mind being on the forefront of it.”

If the RivGen is successful, it has the potential to offset half of the village’s diesel consumption. Hill said the village’s goal, in that case, would be to seek additional funding to purchase two RivGen units. That way, the Kvichak River, which already provides the community with necessities from drinking water to salmon, could also serve as its primary source of electricity.

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