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ORPC progresses demo in-current power Plans tidal and river systems in Cook Inlet and at Igiugig but seeks funding support to test technology in Alaska conditions Alan Bailey Petroleum News
With some of the world’s strongest tidal currents and a wealth of fast-flowing rivers Alaska would seem an obvious venue for power generation using the new in-current, water-driven turbine technologies that are starting to emerge from the realms of research into the world of commercial operation.
Ocean Renewable Power Co., or ORPC, a company formed in 2004 to seek opportunities for harnessing tidal energy for electricity generation, established an Anchorage office in 2006 with a specific interest in the tidal resources of Alaska’s Cook Inlet, Douglas Johnson, director of business development for ORPC in Alaska, told the Regulatory Commission of Alaska April 11. The company has since also pursued possibilities for using in-current turbines in Alaska rivers in rural Alaska to offset the high cost of diesel fuel for power generation, said Monty Worthington, ORPC’s director of project development.
ORPC is in the process of implementing demonstration in-current generation systems using Cook Inlet tidal currents at East Foreland on the west side of the Kenai Peninsula, and in the Kvichak River, by the village of Igiugig, at the southwestern end of Lake Iliamna.
System in Maine The company has been running a test tidal current system in the waters of the Bay of Fundy, between Maine and Nova Scotia, and plans to upgrade that system this summer to become the first grid connected, commercial, tidal in-current project in the United States, Johnson said.
The ice-free waters off Maine provide a relatively benign environment for a first implementation of the technology, with the waters of Cook Inlet presenting the challenges of a high silt content in combination with fierce tidal currents, Johnson explained.
However, ORPC is progressing its Alaska plans while using its Maine project as an avenue to learn more about the in-current technology.
Cook Inlet options In Cook Inlet the company had originally envisaged a pilot project at Cairn Point, at the entrance to Knik Arm at the extreme northeastern end of inlet. However, having been advised that this location presented problems associated with potential disturbance to Cook Inlet beluga whales, the company moved its attention to a site off Fire Island, offshore Anchorage, Worthington said.
For connection to the local power grid the Fire Island site required the use of an electrical intertie that Cook Inlet Region Inc. planned to construct to serve the wind farm now being built on the island. But, with the future of the Fire Island wind farm project subject to uncertainty at the time when ORPC was planning its tidal power project, ORPC opted instead for East Foreland as a project site.
ORPC sees the possibility of multiple tidal power systems at various sites along Cook Inlet and has retained its Federal Energy Regulatory Commission license for the Fire Island site, Worthington said.
The eventual deployment of systems at multiple sites along the inlet would present the possibility of a relatively constant power supply. That is because the phase of the tidal current — the timing with which the tide ebbs and flows — shifts as water moves along the length of the inlet, with the tidal peaks and troughs at Cairn Point, for example, being about 180 degrees out of phase with the peaks and troughs off the southern end of the Kenai Peninsula, Worthington explained.
“So you’d have a renewable energy source that also has some baseload capacity,” he said.
East Foreland With access to suitable tidal currents and the possibility of connecting to the Kenai Peninsula electrical infrastructure without the need for a transmission line, East Foreland presents many advantages as an initial tidal power site, Worthington said.
Work in earnest on the East Foreland project began last year. The University of Alaska Anchorage performed some water current velocity modeling to pin down specific locations for an initial turbine installation and ORPC subsequently placed acoustic current profilers on the seafloor, recording current velocities at different levels of the water column over a complete month.
“That allows us to extrapolate the energy potential of the site over the course of a year,” Worthington said.
ORPC also identified potential interconnect points on the power grid, in readiness for an eventual decision on precisely which location at East Foreland to use for the project. And, using Department of Energy funding, the University of Alaska Anchorage has built a flume for testing the impact of flowing, sediment-laden Cook Inlet water on the key moving parts of ORPC’s underwater turbine equipment.
HEA agreement In January power utility Homer Electric Association signed a joint development with ORPC for agreement for the East Foreland project, Worthington said.
The first phase of the project will consist of a four-device demonstration with a 600-kilowatt rated capacity, to flesh out the cost, performance and environmental compatibility of the tidal power technology in Cook Inlet. The plan is to expand that initial implementation into a pilot project that will eventually be built out to a five-megawatt power plant, Worthington said.
ORPC plans to install the initial 600-kilowatt system in 2014, by which time the company will have seen some run time from its system in Maine. The full five-megawatt system in Cook Inlet might be operational in 2016.
River power ORPC has also been pursuing its Alaska in-river power generation concept.
The company originally hoped to carry out a pilot project in the Tanana River by the village of Nenana in Alaska’s Interior. However, having discovered significant issues with silt and river debris that could damage the generator turbines at this site, the company has opted instead to pursue a pilot project at the Igiugig site, where water in the Kvichak River is relatively clear, thus providing a better initial river site for a test.
“As we’ve learned more about the Tanana River … we’ve realized it has a few too many challenges as a first step into a river,” Worthington said, adding that ORPC is nevertheless working with the University of Alaska’s Alaska Center for Energy Power to find a debris mitigation approach for the Tanana, with a view to eventually installing a system at Nenana.
Meantime, ORPC has tested the installation of its river generation system in water at Nikiski on the Kenai Peninsula and the company hopes to install a river system in 2013 for initial testing.
Funding needed ORPC anticipates its Cook Inlet project costing about $13 million, with about $7 million of that being spent in Alaska, Johnson said. The Alaska Energy Authority has contributed about $2 million in funding. But, with ORPC putting about $1.8 million into the project, the company has been approaching the Alaska Legislature, trying to see how to obtain the balance of the funding. This year the company was denied $5 million in funding from the state renewable energy fund because of a glitch with the timing of the funding application, Johnson said.
Johnson said that financial incentives are essential in helping overcome the economic hurdles facing the implementation of embryonic technologies such as tidal power. Maine and Nova Scotia both have mechanisms that enable the high current cost of tidal power systems to be met with minimal impact on electricity ratepayers, he said. The tidal power in Maine, at 65 cents per kilowatt hour, costs three to five times the average renewable market rate and is heavily incentivized, he said.
“The first kilowatts from the new energy technology are the most expensive,” Johnson said.
But Maine has also seen the benefit of $14 million of investment from tidal power in the local economy and ORPC would like to see the same type of economic benefit in Alaska, Johnson said.
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