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Preparing for the next steps for Igiugig Village council files draft FERC license application for in-river turbine power while ORPC plans next phase of system testing Alan Bailey Petroleum News
Following a successful test of an in-river power generation system in the Alaska village of Igiugig last summer, the village tribal council has filed a draft application for a Federal Energy Regulatory Commission license for an operational system. The village sits on the bank of the fast-flowing Kvichak River and wants to use the river current to generate electricity, to replace at least some of the expensive diesel-fueled power that the village depends on.
However, with further testing needed before a fully operational in-river system can be implemented, the village does not anticipate starting the build out of the system until perhaps September 2016. The tribal council envisages a two-phase project. Phase one would involve the installation of a single in-river turbine while phase two, possibly starting in 2018, would involve the installation of a second unit. Two turbines together would be capable of meeting the village’s average electricity demand, the license application says.
The license application says that, although Igiugig has some wind turbines, the village’s main power supply comes from a power plant with three diesel generators that consume about 30,323 gallons of diesel fuel annually. The cost savings resulting from the use of the in-river turbines could amount to more than $250,000 per year, the application says.
Ideal location Igiugig is located near the end of Lake Iliamna in southwest Alaska - the Kvichak River flows out of the lake. Monty Worthington, director of project development for Ocean Renewable Power Co., manufacturer of the “RivGen” power generation device that was tested at Igiugig last year, told Petroleum News that the village is ideally situated as a location for spearheading the new in-river technology. In addition to the village being a great partner in the project, the river is almost free of the debris that can plague in-river turbine systems at some locations. Moreover, the river is typically ice free, Worthington said.
ORPC’s RivGen device consists of a turbine with helical shaped blades, connected to a submersible generator and mounted on a pontoon structure. The floats of the pontoon can be filled with water to sink the structure to the river bed, for anchoring in position. By refilling the floats with air the device can be refloated and towed to the shore for maintenance.
The focus of last year’s testing was validating the technique for moving the RivGen device in and out of the river and demonstrating that the device could produce power, as planned, Worthington said. Based on lessons learned from that test program, ORPC is in the process of making some modifications to the device. A company on the Kenai Peninsula is fitting a ramp-like fairing to the bottom side of the structure, to increase the velocity of the water flow through the turbine and hence improve the turbine’s efficiency.
“It will increase the efficiency, the amount of power we get out of the same size turbine,” Worthington said.
ORPC is also making some changes to the pontoon structure, to enable the floating structure to be towed through the strong river current with less horsepower - last year there was a lot of drag when towing because of certain structural members on the pontoon, he said.
Integrate the power In addition to testing the effects of the new fairing on the turbine efficiency, this summer’s program will involve further work on integrating the power from the river turbine into the electricity grid at Igiugig. A key factor for the technology, referred to as hydrokinetics, will be its ability to integrate into the type of diesel-powered microgrid that is typical of a rural village.
“Hydrokinetics have a lot of promise, not only to reduce diesel fuel use but, because they’re fairly consistent. If you size the project appropriately, you could even have times when you turn the diesels off completely,” Worthington said.
In fact, the Igiugig program presents a worldwide opportunity for ORPC, given the possibility of using the hydrokinetic technology as a power source for remote communities, if the technology can integrate successfully with microgrids he commented.
The clear water of the river at Igiugig enables an underwater camera to monitor the behavior of fish near the turbine and last year’s tests revealed no adverse interactions with river wildlife. No fish were observed to go through the turbine. However, small fish have been recorded swimming uninjured through a similar turbine device in an ORPC hydrokinetics application in Maine, Worthington said.
Earlier deployment This year ORPC hopes to deploy the RivGen device at Igiugig in July, about a month earlier than last year. That will enable the interaction of different species with the turbine to be observed, Worthington said. And ORPC will continue to collect environmental data, as part of the process leading to the licensing of the power generation system, he said.
Assuming that the system goes into full-scale operation, the idea would be to place the RivGen device in the river for most of the year, removing the device in late April, before broken winter ice starts flowing out of Lake Iliamna, and then re-installing the device four to six weeks later. Annual maintenance could be conducted while the machine is out of the water.
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